Jetting Advice 28MM FS Mikuni, 200X race motor - DUMB AGAIN!!

[Dirtcrasher]

My god, everything I have read, everything I "thought" I understood is making no sense to me.

Telling you what I have for mods means nothing, it's all about how it runs and what it's telling you.....

I am running great on top, 3/4 to WOT so I'm very close on the main which of course has a trickle down effect.

So here is where I AM COMPLETELY LOST!!

I am running a 28 Mikuni that had a 20 pilot to start.

I am up to a 50 Pilot now.

The choke is nearly useless which says RICH and I'm watching my front half of my Suertrapp pipe turn cherry red :mad:

YOU TELL ME!! that means lean!! but the choke being useless means rich!! and those are all 0-1/4 throttle of the circuit!

There are no air leaks, no worn carb, no float problems and I have the conflicting issues......

Does it make any sense to PEOPLE THAT HAVE TUNED AND BUILT MOTORS?? Because it does not make sense to me...

If your choke does nothing, your too rich on the pilot. If your pipe glows red at idle you are too lean!! WTF is going on here??

I would up my pilot to a 55 (from50) which is the LARGEST one they offered at a given site, but then I wouldn't even have to choke it at that point which is wrong in 15 degree weather. It seems to be COMPLETELY asssbackwards??

The ONLY variable is the "air jet" which of course I can't find one piece of literature to say " the air jet is responsible for..............................BLAH BLAH BLAH!!!

I "THINK" it allows more air into the choke circuit when the choke is on. So, if I drop it down the choke may work again. BUT! even then, why at idle with a 50 pilot. 1 turn out is my pipe turning red - LEAN LEAN LEAN!! A 50 pilot jet in a MIKUNI IS LEAN!!!!!!!!!!!!!!!!!!!!?????????????????????????? ??????????????????? NO AIR LEAKS!!!!

I'm so pissed off that I can fix anything mechanical yet this thing makes me feel like a complete IDIOT/NEWBIE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Air jet?? Anyone?? Please!!

I'm not satisfied with "good enough" I want to get this close to dead nuts!!

[Mosh]

What was it doing with the 20 pilot?

[Saul]

Is this a 2 or 4 stroke?

[Dirtcrasher]

Hey Mosh,

Wit a 20 pilot, the pipe turned cherry red immediately and cooked off all of the PC on the headpipe........

If it's glowing at a 50 pilot you wouldn't start dropping down would you??

IDK if that Mikuni "air jet" is doing this but the choke circuit and 0-1/4 throttle do not seem right.

SAUL- 4 stroke 200X, full porting, 12:1, race gas, no AB lid, aggresive cam, lightened flywheel and a 28MM Mikuni flatslide carb.

It is LOVING the top end whi9ch is roughly a 280 main jet.

[Mosh]

What is your compression at?

This is the built to the hilt 200x right?

Have you ruled out timing?

[Dirtcrasher]

What is your compression at?

This is the built to the hilt 200x right?

Have you ruled out timing?

I'll check it again in the next few, but it was at about 190PSI.....

Timing on a 86 200X is supposedly FIXED, but, I'd be more than willing to oblong some holes and either advance or retard it.

In the Service manual, when timing is off, they suggest ohms tests of various components (I've got many repeats of parts that could be swapped, but I never liked being a "parts changer" :D)

What are your thoughts on the ignition timing? The thing is awesome from 3/4 to WOT.......

Hey, I can run it. But... I've ALWAYS had a problem when "things" don't make sense to me and thats whats going on right now.

Thank you all for any input and or advice! :beer

[edog]

Could the problem be in the exhaust valve and port?

[Billy Golightly]

Hey Dirt, didn't you have one of those Chinese Mikuni copy carbs or is this one of the actual Mikunis?

[edog]

You NEED to advance your timing.

[Mosh]

I am not going to try to pretend I know everything about jetting.
Honestly, I have seen 2 identical engines run different jetting before,so everyone is unique.
I would think that rich of a pilot would be more than enough.
So all I can do is throw out some theories..
A) 110 gas doesn't combust properly in cold temps..
B) Maybe your cam duration is letting unburnt fuel out of the head.Therefore I would at least try to look at cam timing more closely.

Even all the new 450s glow at the pipe.
I believe this to be becuase they are so heavy in exhast cam duration,some of the combustion takes place in the pipe.

Edit.......You said you just "picked out" a cdi that looked good.
It wouldnt be the first time a CDI was the wrong unit.All the timing advance is built into them,and vary from bike to bike,even though they may "bolt on"

[Jason Hall]

Dirtcrasher, I would think that If the choke makes no difference, then you are still lean. If the choke being on doesn't change anything, and the pipe Is glowing your not getting enough fuel. If the timing was retarded, like Mosh suggested that could cause excess heat In the pipe. What kind of carb Is on It? I know It's a Mikuni, but is the air/fuel screw In front of the slide? or behind It?

[Dirtcrasher]

Hey Dirt, didn't you have one of those Chinese Mikuni copy carbs or is this one of the actual Mikunis?


Hi Billy, At TF08 I had a 30MM roundslide (copy) thats why no one had any jets for it and I ended up drilling the pilot way to fat, running the main way to lean and not having race gas. Then the rain/mud hit and I couldn't tune any more.......

I've got a 28MM Mikuni flatslide now and the slide was worn so I tossed in a new slide and I had new floats so I put them in also.

It is running SUPER on the top but the choke not doing crap and the pipe glowing bothers me... BUT, Mosh has seen headpipes glow before?? I mean. it is a very thin Cobra headpipe - is there enough heat to create this condition and COULD I go leaner on the pilot??

EDOG - Maybe so, but wouldn't I also have problems up top?? I do appreciate anyone's thoughts and arguements. Thats how we learn!!


ANYONE on the "airjet" and it's function?? I assume it's simply in the choke circuit and then done?? anyone??

[edog]

You could always try a dial a jet.

[edog]

You probably look into Jet hot coating the header or wrapping it with header wrap.

[Mosh]

Some consider a 450 glowing to be normal...
I dont think I would be comfortable with it.
You are definatley not the type to assemble the engine wrong, so I am gonna rule that out right away.

If it were me, I would start from square one.
A completely different carb.
I have a carb for a 250R I and others spent over 10 hours on and never got the thing right.
I now use that carb to throw at stray dogs getting into the thrash.
Sometimes it is best just to start over...
But I still wouldnt rule out timing if a different carb doesnt help.
I dont care for Mikuni's, but I never had problems with them either, on a stock machine with little mods.

[Dirtcrasher]

Dirtcrasher, I would think that If the choke makes no difference, then you are still lean. If the choke being on doesn't change anything, and the pipe Is glowing your not getting enough fuel. If the timing was retarded, like Mosh suggested that could cause excess heat In the pipe. What kind of carb Is on It? I know It's a Mikuni, but is the air/fuel screw In front of the slide? or behind It?

Thanks Jason, the airscrew is in the back half of the carb at 1 turn out. Thats the only place we had any 0-1/4 throttle response and it made it idle.

Correct me if I'm off..... But if I can start a freezing cold motor doesn't that mean my pilot is too rich?? It's cold as hell outside, I kick it with the choke on - it bogs right away - so I take the choke off and it runs freezing cold....

Doesn't that mean the Pilot is too rich?? but the headpipe says lean??

The choke and plunger are brand new also!!

I always thought that if the choke did nothing, you were rich in the pilot/airscrew circuit??

Thanks guys for the thoughts and quick responses!!!!!!!!!!!!!!!!!!!!!!!!!!

[edog]

This is it-

http://i257.photobucket.com/albums/hh220/Dirtcrasher/NewMikuni3.jpg

Maybe you should try a bigger carb?

[Jason Hall]

I edited my last post, but you might have missed it. If the A/F screw Is behind the slide you are adjusting AIR, not fuel like a normal 4 stroke carb.

[Dirtcrasher]

Does the carb have an Air/Fuel SCREW?


This is it-

http://i257.photobucket.com/albums/hh220/Dirtcrasher/NewMikuni3.jpg

http://i257.photobucket.com/albums/hh220/Dirtcrasher/NewMikuni.jpg

I believe it is an AIRSCREW not a fuel screw.......

Anyone know what the "AIR JET" does?????????? It's in the back half of the carb, just where the air box boot mounts.....

[Dirtcrasher]

I edited my post because you answered my question. If the carb has the A/F screw behind the slide, you are adjusting AIR, like a 2 stroke. A 350x or normal 4 stroke carb has a FUEL screw In the front of the slide. Remember now you are adjusting air, and not fuel when you adjust the A/F screw on your carb. What happens when you tunr the A/F screw all the way In?



Thanks Jason......


So that means that if I turn it in I am taking air away from the starter circuit correct??

I'm at 1 turn out that idles but if I turn it in more, I imagine I am letting more fuel into the starter/idle circuit??

But, if I let more fuel in, how can the choke be doing nothing at this setting I'm at now? More fuel with closing off the air would continue to allow the choke to be useless - no??

[Jason Hall]

Ok, I know your not a Dummy LOL, but Is their a chance that the thumb throttle Is holding the slide up? It also looks like thats a 2 stroke mikuni. I guess from what you have said, the choke being turned off does make a slight difference. So I would for sure say you are correct to say It's rich. If the slide Is held up by the cable, then the air gap could be Inconsistent & could make the Idle Inconsistent.

[Dirtcrasher]

Sorry........ I made the dummy comment because some people are beyond the very first critical steps and thoughts :lol:

Nah, there is plenty of cable slop...

Everything I've ever owned needed the choke for 30 seconds to a minute.

This does not, which (I thought) told me that the starter circuit was too rich.

Mind you that I have been dickin with this for awhile now, it wasn't a perfect running motor at any point. It ran at TF with 98 octane and 50% of the power it has now....

To me, I should drop down to a 40 pilot, but that would be even leaner and the headpipe would get even hotter... Is a glowing headpipe normal?? I don't think so myself with ANY mods.....
]
Maybe I'm wrong??

Of course I'm wrong, this just doesn't seem right to me.

Is it at all possible that I have to go leaner on my pilot and richer on my airscrew?? Just throwing it out there guys......

I do seem to be somewhat flat on the bottom.

[Billy Golightly]

THis already sounds similar to the gremlin I've been chasing on my 86 ATC250R thats driven my to extreme ends of insanity.


Sparkplug gap, and heat range? Good closeup Picture of the plug would beneficial to me.

I'm leaning towards timing, myself at this point. I don't agree with the red glowing 450 pipes being normal. I've seen it happen but its not a real common thing here and any of the pros or pro am riders I've seen don't ride with glowing pipes.

Are you SURE, you don't have any airleaks? How do you know?

On the Keihin's and my limited experience with the bigger Mikunis, the airscrew controls air and fuel mixture at idle and just the very beginning of the throttle range where the pilot jet picks it up.

And I'm not positive, but I'm pretty sure the bigger the #, the bigger the jet with the mikuni's just like the Keihin's but just a different range. Like a 320 mainjet is still richer then a 280 main for Mikunis. I have a few pilots for a bored 38mm TMX series and bigger=bigger and smaller=smaller.

[Jason Hall]

Ok, I would drop the pilot back down. I feel that you are tuning a 4 stroke with a 2 stroke style carb. I'm not sure It will come Into tune!!! Most all 4 strokes have a fuel screw, not an air screw. Remember this. Air goes through the pilot hole In the rear bell of the carb. With an air screw you are adjusting the air before It contacts the fuel to be pushed through the carb. With a fuel screw, the air has allready pushed fuel against the screw. I think that the Idle circuit of that carb Is to big for a small 4 stroke. I'm not that familiar with the flat slide Mikuni's. I would put a 32mm FCR on that engine.

[Mosh]

I thought all 4 stroke carbs had the air screw after the carb towards the cylinder?

[Jason Hall]

Thats what I'm saying Mosh, the 4 stroke has a Fuel screw. If the screw Is In front of the slide your adjusting fuel. If the screw Is behind the slide your adjusting air.

[oscarmayer]

i always thought the pilot was for idle and low range. now assuming this is true, why a 50? that means you really need a 36-38 pilot most likley.
now from what I understand the MAIN jet is what handles everything from about 60% and up on the throttle if i rememer correctly. assuming i'm correct(my memory has been having issues latley), then that means your main jet is too lean.

drop back to a 38 pilot, and then up the main by like 3 sizes to start. set the needle in the midle clip (if the flat slide has one i forget if it does or not) and start from there. if your at 2/4 your out of the pilot jet range and running only on the main jet if i rememebr correctly.

[Daddio]

It does look like a 2stroke carb. That could be whats causing the problem on the bottom. Check this link.
http://www.thumpertalk.com/forum/archive/index.php/t-595079.html

[Jason Hall]

It sounds like he has the needle and the main set pretty close. The pilot Is where his trouble Is. Idle to 1/4 throttle. Is there a chance the slide Is In backwards? If the cutout Is facing forward, It will pull fuel through the main jet.

[Dirtcrasher]

This might be a 2stroke carb modded to work with an 86/87 200X......

People say 2 stroke or 4 stroke carb, but what is the difference anyhow??

I just went for another blast.... It is fast as can be on top and loves life!! Down low it is erratic and stumbles.

This is the plug which says "RICH" to me and I'll bet I am a bit rich on the main but it seems to love to be WOT....

If it is rich, why is a 50 pilot glowing the headpipe!!

http://i257.photobucket.com/albums/hh220/Dirtcrasher/PLUGRaceGas.jpg

This is also RACE GAS which definitely seems to affect the plug color reading...

I think I can take that main down a few thousandths...... but I certainly have a 0-1/4 throttle problem....

Dam, I even downloaded the Mikuni tuning manual and not one frigin page says " the air jet is primarily responsible for.........."

Thanks so much for any help guys and I WILL get this and I WILL tell you all what I find....................

Again "Jetting is no easy task!!"

[Mosh]

Mark just told me to have you drop down the pilot and up the main..

Most of them 450's will glow the headpipe at prolonged idle,especially if it is dark you will see it.
The cam duration is so high at idle on them.
They are made to be revved up to stay clear of unburnt fuel..

[Billy Golightly]

Dc, that looks to be an "8" heat range plug, if its an NGK brand, find a "9" and a "10" even if you have to order them. And try them. Sounds like a band-aid fix I know, but you wouldn't believe the experiences and differences I've had with different heat range plugs.

[oscarmayer]

it looks lean to me. tmay be jsut the photos, but that looks like rust not carmel tan. rust is usually caused by rich, then very lean conditions. if it was lean all the time, then it would be whiteish color. ir it's good, it's carmel tan all over.

i think your low end is way rich and the top is a bit lean.

[Dirtcrasher]

Mark just told me to have you drop down the pilot and up the main..

Most of them 450's will glow the headpipe at prolonged idle,especially if it is dark you will see it.
The cam duration is so high at idle on them.
They are made to be revved up to stay clear of unburnt fuel..


Thanks a bunch MOSH!!, Mark gave me a yell..... Just to talk with him is always a good time!!

I think I have to get the hell out of Massachusetts!! Aren't too many "good" people left in these parts...............................

Allot of stuff Mark said made sense, and he's definitely done his share of tuning and I always enjoy talking with him!

I'll be back out there tomorrow :beer

I'm gonna start by dropping the pilot.

[Dirtcrasher]

Dc, that looks to be an "8" heat range plug, if its an NGK brand, find a "9" and a "10" even if you have to order them. And try them. Sounds like a band-aid fix I know, but you wouldn't believe the experiences and differences I've had with different heat range plugs.



Hey Billy,

Funny you mention it, it should be a 7 but I'm running an 8, I'll play some more tomorrow after my conversation with "Garage Boy" but I'm willing to see what difference the heat ranges does :D

[Billy Golightly]

7? What brand are you running? I think on the Champions the lower the #, the cooler the plug, and the opposite for the NGKs. Either way I'd try a COLDER plug first.

[SWIGIN]

all i can add is i had a 85 200x with the same carb and similar mods and the pipe glowed red......till it blew up days later.

this was 20 years ago so dont ask what jetting i had, cant remeber that far back.

but that was the last time i ran a mukuni carb....i hate those things

[Dirtcrasher]

all i can add is i had a 85 200x with the same carb and similar mods and the pipe glowed red......till it blew up days later.

this was 20 years ago so dont ask what jetting i had, cant remeber that far back.

but that was the last time i ran a mukuni carb....i hate those things



GREAT NEWS!! THX SWIGIN :w00t:

At least I know what "COULD" have happen :D

[honda250sx]

The air jet will effect the 1/2-Full throttle condition. The air jet meters air for atomization of fuel.

[Bryan Raffa]

The air jet will effect the 1/2-Full throttle condition. The air jet meters air for atomization of fuel.

you got that wrong.. from Idle to 1/2 throttle it effecs the most


Clean the air filter and warm the bike up. Accelerate through the gears until the throttle is at full throttle (a slight uphill is the best place for this). After a few seconds of full throttle running, quickly pull in the clutch and stop the engine (Do not allow the engine to idle or coast to a stop). Remove the spark plug and look at its color. It should be a light tan color . If it's white, the air/fuel mixture is too lean and a bigger main jet will have to be installed. If it's black or dark brown, the air/fuel mixture is too rich and a smaller main jet will have to be installed. While changing jets, change them one size at a time, test run after each change, and look at the plug color after each run.

After the main jet has been set, run the bike at half throttle and check the plug color. If it's white, lower the clip on the jet needle to richen the air/fuel mixture. If it's dark brown or black, raise the clip to lean the air/fuel mixture.

The pilot circuit can be adjusted while the bike is idling and then test run. If the engine is running poorly just off of idle, the pilot jet screw can be turned in or out to change the air-fuel mixture. If the screw is in the back of the carburetor, screwing it out will lean the mixture while screwing it in will richen it. If the adjustment screw is in the front of the carburetor, it will be the opposite. If turning the screw between one and two and a half doesn't have any affect, the pilot jet will have to be replaced with either a larger or smaller one. While adjusting the pilot screw, turn it 1/4 turn at a time and test run the bike between adjustments. Adjust the pilot circuit until the motorcycle runs cleanly off of idle with no hesitations or bogs.

it must be done in that order! starting with the main jet .. and get come color first..

[honda250sx]

Not so. If you look at Mikuni's factory manual it states 1/2-full throttle. I can email you a PDF.file grass hoppa. Not my first rodeo either.

[Dirtcrasher]

So now were saying the the air jet works with the main jet.......

Thanks Mikuni!! Just one more variable to play with!!

SWEET!!

Thanks for all the help and advice everyone, I had things to take care of today but I will toy with this tomorrow.

[brapp]

well i am learnign a littl ebit here so please continue and good luck with it all.

[honda250sx]

Dug up some info on that little TM28mm trailprotrailprotrailprotrailprotrailprotrailprotr ailpro. Steve it shows no airjet for that model?

http://i71.photobucket.com/albums/i151/brauerpower/tmcarbs.jpg

http://i71.photobucket.com/albums/i151/brauerpower/tm.gif

[NINJA]

Dammit! I'm so busy right now that I don't have time to write it all down on here. I'm giving you a call Steve. I can help you out with this.

[oscarmayer]

again, (assuming your not ignoring me like before) your too big on the bottom and too small on the top, but what do I know right? I'm jsut a dumb @$$$ who knows nothing, so maybe it's best that i'll stop helpin.

[Erics350x]

^^^WTH^^^ Did i miss something?

[Dirtcrasher]

again, (assuming your not ignoring me like before) your too big on the bottom and too small on the top, but what do I know right? I'm jsut a dumb @$$$ who knows nothing, so maybe it's best that i'll stop helpin.



I refrained from answering to your post ......

I'm not ignoring you, your just assbackwards as far as everyone elses opinion.

You look like you need more help than me... Do you need "POST" recognition or something?? Doesn't mom still hold you?

More tuning tomorrow!! :D

Thanks for viewing!! :welcome:

[The Goat]

Dc yours is doing exactly what my 85 was doing when it was like 6 teeth off on the timing chain.

The pipe would glow, but I was up to a 170 main or so keihn jet. It just kept going faster... And faster. I had pet someone else time it and yeah that didn't work out. I'm not saying you're misstimed, you wouldnt do that.

But have you considered all of your mods are doing a number on the stock cdi/electrical?

Maybe I'm way off base here, but maybe your portwork coupled with highligt duration cam is allowing fuel to enter into the pipe before it can ignite. Basically I mean too much duration coupled with a ton of flow.

Unlike oscar, I am actually a fool when it comes to tuning, but common sense says you're getting fuel in that headpipe... And if you aren't mistimed...

[Nick_R_23]

I would also say its a timing problem also. When I redid the top end on my truck, I forgot to unplug the timing advance before I set the timing. Ended up being something like 12* out of time. Ran like crap and acted like a fuel problem. Took it out for a test drive to see if it would clear up, and when I got back the headers were glowing cherry red!! Re-set the timing and it cleared up and ran great after that.

-Nick :TrikesOwn

[Dirtcrasher]

I have not ruled out anything yet, but I will be jetting today.....

The ignition timing is fixed. It cannot be adjusted.

The cam chain timing is dead nuts, not saying I couldn't advance it a tooth but I'd be willing to bet on a half tooth. Which, of course is impossible with the 86 200X because the sprocket is welded to the cam. You would have to go one complete tooth either direction.

I can't see anything being 6 teeth off without bending a valve.

My jetting is close, it was more the mere panic of seeing a glowing red headpipe at which numerous "tuners" have claimed it to be perfectly normal.

[DeePa]

the im no dummy part of your thread title is misleading...

[oscarmayer]

^ exactly. if all the otehr advice is not working, why not listen to someone who is not following what they are doing? wait, that makes too much sence. (not callign everyone dumb, but the chopice NOT to try all ideas is when nothing is working). i'm trying to tell you how to tune THAT carb on a 4 stroke (done it a lot in karting)but your ignoring me and insulting so, yea what ever man good luck with it.

[DeePa]

dude i was joking, know him outside of here...

The bike actually runs great up top and the "rust" color is from the race gas...No need to TOUCH the main jet, not a chance in hell...

His question was about the red headpipe...which can be normal in dark situations when you have a high performance 200 cc motor, and your modded head 200e doesnt count...sorry...

actually we joked about how funny your first response was...

go open your shop and charge someone 700 after you tuned their carb because it took you 70 hours at 10 bucks an hour because you were CLUELESS at what you were doing...K THX BYE

OH and dont PM me telling me to be nice because i dont give a trailprotrailprotrailprotrailpro, thanks

[The Goat]

dc...no lie, my flywheel line was lined up pointing at the cam, rather than being in the middle of the hole. that should give you an idea of how mistimed this thing was.

I think your issue is a thin headpipe, a ton of flow, and a carb that still needs some tweaking.

have you tried recording where you are now, and instead of tuning from top to bottom, tuning from bottom to top?

sounds odd, but I've been reading a couple of articles from guys who do just that

[3Razors]

If you have the stock 200x carb maybe just for experiment throw it on with some bigger jets and see how it runs? It surely wont hurt anything and if it runs better with the stock carb then chances are your timing and everything else is ok but the 28mm is still out of whack.

Did you buy this 28mm as a kit from White Bros? I have the White Bros catalog in my hand and they sell the 28mm Mikuni FS carb as a kit for 200X, supposedly comes with a twist throttle also. If you bought the carb from a shop almost all of them are setup for 2 stroke use which you will have to change every jet over includind the needle valve and possibly the slide for 4 stroke use. I would say call White Bros and see what they set it up baseline but if I remember right the company was bought out or something a couple years ago.

[NINJA]

I think your issue is a thin headpipe, a ton of flow, and a carb that still needs some tweaking.

have you tried recording where you are now, and instead of tuning from top to bottom, tuning from bottom to top?

sounds odd, but I've been reading a couple of articles from guys who do just that

That's exactly what to do with this one. Start out by richening up the float level and it will allow you some leeway with all your other circuits in the carb. That cam has so much duration on the exhaust lobe that part of the combustion process takes place in the headpipe. It's NORMAL for the headpipe to glow on a fully built 200X motor. The bottom end throttle response suffers on a modded out small displacement 4 stroke when it's head is flowing so much more. It has lost the intake velocity that it used to have. That motor is built to live at 5/8-WFO at this point. It's close Steve, real close to right. With a higher float level you should be able to lean down that pilot a little bit. See if you can get a couple different size slide cutaways from Sudco or Mikuni and you'll be able to tune that throttle response off the bottom end a bit. They range in size starting at 1 to 3.5 in .5 increments. That will be your fine tuning of it.

Anyone wanna argue with me? Oscar?

[The Goat]

and the goat steps up to crush one out of the MFing park!!!!!

just kidding, bored at work guys.

keep us updated DC... ya never did send me your paypal addy

[Dirtcrasher]

Hi guys, I'm done playing for the day with positive results.

Oscar - I don't know what to say but you were so quick to feel that I ignored you, I don't ignore anyone - I just felt you were wrong. IDK what to say, but look at some of you other posts - I think your a cracker....

Back on topic. I went out today and toyed with the float tab just a hair, changed to a 35 pilot and messed with the main jet. I felt that the pilot was a bit rich and the main a bit fat - .071" is a very fat main. Here's what we had.

I jumped down a little low and worked my way up, here are the plug chops.


This was .o57" chop - felt very flat.

http://i257.photobucket.com/albums/hh220/Dirtcrasher/057Mainjet.jpg

This was .063" chop - flat again but better

http://i257.photobucket.com/albums/hh220/Dirtcrasher/063mainjet.jpg

And last was the .066 chop which felt and showed me a good color.

http://i257.photobucket.com/albums/hh220/Dirtcrasher/066Mainjet.jpg

I have as bit of stumbling down low, but the airscrew may take care of that. It loves to be wide open and screams up high. Which I'm sure has allot to do with the cam that came with this ported head. This is supposedly hand ported from Mickey Dunlap himself and it loves to be on top :D

I quit for today and I'm very very happy with the results. I did not touch the valve or ignition timing or anything else aside from whats in this post.

It's fast, very fast and I'm feeling allot better today!!

[Mosh]

So did dropping the pilot help the choke?
Has the glowing pipe gotten any better?

It still looks to me like you could go up on the main a smidge...They say jump up till they stumble,then back down?


Thatsa why I like them thangs without valves...LOL

I still think jetting in this cold weather with 110 fuel is hurting you results.

[The Goat]

quick quesiton... aviation fuel? if so, isn't it meant to be burned up high in the low temps anyways?

not being a smart ass, just trying to ask a legitimate question here. lol. like does av fuel burn better in the cold than the heat?

[honda250sx]

DC those look good. You seem to be back on track. Hell its taking longer to jet than it did to build.

Looks like you will get it no matter what. The cold weather isn't helping and its going to get colder this week.

[Dirtcrasher]

So did dropping the pilot help the choke?
Has the glowing pipe gotten any better?

It still looks to me like you could go up on the main a smidge...They say jump up till they stumble,then back down?


Thatsa why I like them thangs without valves...LOL

I still think jetting in this cold weather with 110 fuel is hurting you results.

Yep, I agree completely....

I think that the main could go up a few thousandths, But, a drill index between 2 given sizes is too much. Thats why Suddco told me to get it close and then buy a few jets in that particular range....

As far as the valves - it just adds one more variable and makes it less reliable:lol:

I felt happy with where it stood today..... Lets see what it does tomorrow. :beer

[Daddio]

Hey DC, just out of curiosity, what type of 110 fuel are you using? Leaded, unleaded, oxygenated, that type of thing.

[Bryan Raffa]

Yep, I agree completely....

I think that the main could go up a few thousandths, But, a drill index between 2 given sizes is too much. Thats why Suddco told me to get it close and then buy a few jets in that particular range....

As far as the valves - it just adds one more variable and makes it less reliable:lol:

I felt happy with where it stood today..... Lets see what it does tomorrow. :beer

fine tune that main a little more then....

After the main jet has been set, run the bike at half throttle and check the plug color. If it's white, lower the clip on the jet needle to richen the air/fuel mixture. If it's dark brown or black, raise the clip to lean the air/fuel mixture.

[Billy Golightly]

.066 plug gap?!?!? Holy trailprotrailprotrailprotrailpro DC, what in the world is making run you that much? What does the manual call for??? Hell I don't run anymore then .015 on my stuff, most of the time its .012!

[The Goat]

Billy I could be wrong but I think that was what he drilled his jets to.

[Billy Golightly]

oh geeze. I went back and read that post two more times, but I get it now. You are correct, those were main jet drilled diameters.


/dunce

[honda250sx]

Tis correct goat-san

[oscarmayer]

if I'm a "cracker" why are you doing exactly what i recommended? :P yea really, all messin asside, your doing everythgin i said. your leanign the bottom and your drillin the main (richening the top) so am i still a cracker and an dumbbutt? :P I've tuned THAT particular carb dozens of times. that model is differen than most. the pilot doesn't do that much in it. that carb was designed for a motor to run WOT most of the time. so what your going to have to do is trick it to let you tun a mid range and low end. that's why I told you different.

[Dirtcrasher]

I'm sorry, I meant to call you a WEINER....:lol:

I never went richer, I went leaner on the main. The reason it is drilled is I took out the .072 jet and jumped back down to a .055 and did some legitimate plug chops with a fresh plug each time.

It ended up having a nice caramel color at a .066 main jet with no hesitation. So in the end I went leaner on the main, from a 50 to a 40 to a 35 on the pilot and the air scre is out .5 turns.

Mosh, the CDI was from 5 or 6 CDI's but all 86/87 200X models....

A few guys have asked about the fuel, it is 260 GT PLUS 104 octane.

It's raining now but I'm gonna do what Raffa suggested. I do believe I may be able to raise that needle but I'll let Mr' Plug tell me what to do.....

Drill index's jump about .003 and drill always drill a bit more than that because they are a drill and not a straight flute reamer. So, at this point, I'd like to buy thew few jet within the range I'm at which might be a 280, 285, 290 ?? I can't find where these sizes correspond anywhere...... but whatever is in the .066 to .071 thousandths of an inch.


Hey, you know what rhymes with weiner???











































































































LEANER shens

[The Goat]

Dc I want you to know I just laughed hard enough to scare the puppy.

[brapp]

gla dot hear your makign resaults.

[oscarmayer]

as long as your making results that's cool. yea those carbs are pretty finicky. i had ne that i had to setup for a 2-stroek 1 week then the next redo it for a 4 stroke jsut cause the guy wanted to save $. he eventially got tired of spending $ on parts and got a second for the 4-stroker.

[Bryan Raffa]

when lookin at the plug ...have a flashlight ready to read the proper area on the ceramic...this one has the threds cut off to show you.. where too look:beer

[Dirtcrasher]

Thats the thing Bryan... I think allot of people think they can look at the electrode and call it a plug chop!

The things I've been reading tell me you have to cut the metal off and read it the way you just posted.......

Some people may ignore it but it can also mean the difference between performance and or blowing up!

[Russell 350X]

I never relized that jetting can be so difficult, normally I make it "good enough", this is deffinetly "fine tuning" lol.

[The Goat]

so the ceramic in those areas should reflect the usual colors we look for?

[Erics350x]

yes, your looking for tan at the bottom of the ceramic. with two strokes i like to pull the head yearly and check piston wash, it should have about a finger nail thickness of clean area around the edges of the piston.

[Dirtcrasher]

I never relized that jetting can be so difficult, normally I make it "good enough", this is deffinetly "fine tuning" lol.

Honestly, were not even CLOSE to fine tuning.....

There are different needle jets and seats and they have different cutaways on the throttle slide!! Adjusting the float level, the air screw and the amount of oil on your air filter....

You could go crazy OR, you could get things very close and super fine tune them in for the ultimate performance in the entire throttle range :w00t:

For us "hackers" I think the average needle that goes up and down, a couple turns of the air and or fuel screw and the pilot and main jet increments; I would IMAGINE it's quite close enough!!

At least the thumpers have some room for forgiveness but the pingers can have damage in just a few minutes with lean jetting.

We all go thru stages, and jetting isn't something I have done extensively. I remember when I got a Banshee for some work I had done on someone's backhoe. The head was shaved quite a bit and it had Toomeys on it. But, the owner had been murdered while it was being built. I got this and that and din't know much about race gas etc etc at this point. I sold the head and the exhaust and the carbs. BUT, the carbs had not been jetted. Although I gave him a great deal on all the parts, he told me it ran terrible when he installed them. Unfortunately, I didn't know enough to help him at that time and he kept the parts but went back to stock. If I wasn't JETTING STUPID!! I would have said "you have to run race gas with the higher compression and you have to jet those carbs!! But, I didn't know :(

I feel bad, because I know that today I could help him allot more. And it was just a few years ago........

Jetting is based on a ton of experience and the ability to read a plug. My mechanical abilities far surpass my tuning abilities and those come tough and deserve respect when you work with someone that knows jetting very well!!

The day you feel your an expert and don't need anyone elses input is the day your all done.

YOU CAN NEVER LEARN TOO MUCH!!

Take everything people suggest with a grain of salt and ask, test and tune until you get it right :D

I'm not there yet, but it's tough this time of year. I'll get there, I'm still so disappointed to have built this 200X in 20 days and if I had a half a clue, it with have been a good opponent at TF08 :cry:

[Dirtcrasher]

Hey guys, so off I went to Pennsatuckayuckafuckaway (which BTW, was an awesome experience :D)

At this point, I am merely posting everything I have experienced to share with other guys that want to learn and tune. I believe we are way past the obvious associated problems that are normally found in this type of tuning/troubleshooting......

As mentioned previously, I had bought a brand new Mikuni 28MM flatslide (same carb) BUT, it has not been modded to directly bolt on to this engine. I have to get my machine shop squared away before I can machine and then run a completely brand new carb.

Prior to any of this jetting and testing, I stole all the parts from the new carb (slide, float, choke etc etc) and installed them in the used carb body to try and help with any of the wear within this carb which I felt may had been creating all these odd tuning problems.

It was cold when DEEPA and I got there friday and a bear to get started, once I got it started it ran well. I rode it on and off numerous times and everything was fine until that evening. Then, I believe both Raffa and Loius rode it and had some stumbling issues in different ranges.

Saturday morning it simply would not start, or I should say that it would start but wouldn't take any fuel off idle and the choke seemed to do nothing. I could take it off completely at 15 degrees outside and it would still start, then die and you couldn't even tap the throttle.....

SO, I felt I needed to lean out the pilot. If the choke does NOTHING then you must be rich! or so I felt. I dropped the pilot from a 35 to a 25. At this point it started and the choke worked for a short warmup time and then I could take it off choke; which seemed to me that the choke was doing it's job and indicated my low circuit fuel system was close - that being the air screw and the pilot jet.

At this point I wanted test pilots. Louis hopped on and felt it was flat in the middle and should have more on top. DEEPA felt there were issues but wanted me to "RUN IT!!" however I felt we could tune it better.

So, one step at a time. I lowered the needle clip one notch (effectively raising that needle or mid fuel cicuit just a bit richer) and both Mike and Louis liked the change. Then Louis still felt it had more on top to go so I drilled the main jet out about .004 larger than what was in there. Mind you that it was 20 degrees and no air box lid was in use.

At this point both my test pilots felt it was dead nuts everywhere. 10 minutes later it wouldn't idle correctly :cry: almost surging up and down and if you touched the idle it would rev up which indicates an air leak. But up top, it runs like a rocketship. Of course thats the cam grind being a flat track or top end cam, but I know that I have issues down low.

Aside from an idle that we could not lower and some RPM changes, it ran very very well in this temperature and the elevation at BRAPPs. That night the temperature dropped and Russ rode it only to tell me that on top it ran like a madman but stumbled down low from 0 to 1/2 throttle.

There are simply no air leaks in this system aside from air leaks within the carb. When I got the carb, the black (teflon?) coating on the slide was extremely worn in the corners so I'm sure the mating surfaces to that slide in the carb body are also worn. I'm certain that this isn't helping.

Otherwise, I just want to get out of the way that this is a tight motor. New valves, top end race cam, new OEM intake and rear boot and no air leaks possible aside from the carb body itself. Timing is dead nuts, ignition system fresh..... What I'm getting at is there simply HAS to be some internal air leakage issues with this carburetor and my ability to tune it.

I am still COMPLETELY 100% satisfied with the purchase of this carb, for one - I had nothing to run aside from worn 26MM Keihins and if I never bought this carb, I couldn't copy what White Bros had done to this carb back in the day to get such a clean fitting performance carburetor.

Something I'd like to hear more about: There have been different people telling me that this is a 2 stroke carb and I'll never get it right. This only drives me further towards getting it to work and work 100%. This carburetor was made by Mikuni and modded by White Bros back in the day specifically to run on a 4 stroke engine.

Although I had spoke with him last week, on my ride home I heard a voice mail from NINJA. One thing he brought up was the difference in the choke system from a 2 stroke to a 4 stroke carb that really made me think for a bit. Just about every 4 stroke choke that I have seen is a butterfly choke that blocks off most off the air at the rear bell of the carburetor during a cold start. And when you blip the throttle, that butterfly remains closed while the needle jet and other circuits are allowed to warm up the engine in the now choked fuel rich condition. This setup within this carburetor, I am richening the fuel circuit but the second I blip that throttle the slide raises, the air is allowed into the circuit and it dies instantly. I don't think I can buy a pilt large enough to correct this yet still work when it's warm. When we had the 55, 50, 45 and 40 pilot installed it was definitely too rich down low when it was warmed up.

Without a butterfly valve, am I incorrect in feeling that possibly I will not get a choke circuit to work properly?? Especially in such cold weather?? I have tried from a 20 to a 55 pilot and that choke circuit simply will not work properly.

I am convinced that I have some air leaking due to wear within the carburetor body but again, I'll never regret buying this carburetor because it has forced me to jet, jet and jet again and ask/ponder things I'd never have thought of before.

Will the new carburetor resolve any and all issues?? I won't know until I machine it and fit it up but that lack of a butterfly valve certainly makes me wonder if in 10 degrees I can make this work. Will the fresh carb work 100% from 40 to 100 degrees?? it may but I won't know for awhile........

In the meantime, I have a new 30MM Keihin and I just got in the jets for it. It's the one I ran at TF08, BUT, I didn't have any jets at all to test with and now I do. So, this week I will put this carb back on with a richer pilot and jet jet jet and see how it runs. Even if I get it running great, when I machine the new Mikuni, I WILL put it back on and see if it works.

You'll never learn anything by giving up!!

Thanks to any and all that have helped, put up with my ranting and continued to follow this topic :beer Persistence will persevere eventually :D

[Louis Mielke]

DC, I'll say it again. I think we had it as close as you could possibly get that carb with it leaking like it did. The odd idle is most definitely a leaky carb (not that you needed it repeated, I just liked typing it again lol) I felt it ran just as well down at the ice pond that night as it did when we were jetting it that afternoon.

I think you'll loose what little bottom end you have with that larger carb.

I personally would work on getting that new 28mm machined. I really liked the power that bike has, just need to fix the leaky carb issue.

[Vealmonkey]

Are you keeping in mind that if you have a cam that is set up for top end, that more often than not the bottom end really suffers? It may not be a carb issue at all juist that the cam is not working at the bottom end of your power range. Cams are often a compromise. Top end cams are meant to work best and make the most power with your throttle wide open and you engine revving out, sometimes at the sacrifice of the lower end. Manufacturers figuring you are only going to have the engine idling for a short time before you are pegging the throttle wide open. You may or probably never will get any carb to work with that cam on the lower end. That is why most race cars have very erratic or lumpy idling or you hear alot of race cars constantly revving their engines at idle so they can keep the engine running. If you want a cam that works in most ranges and a trike that works better on the bottom end, I think you'll have to look at getting a different cam and quit beating your head against the wall thinking it's the carb. Just my opinion.

[Louis Mielke]

After talking with DC saturday I'm confident he's well aware of the sacrifice on the bottom a top end cam takes.

This 200's jetting was definitely out even for a top end cam. I think there are just to many variables to get this carb jetted right for max power AND all around running. It's probably gonna hafta be one or the other. The throttle body itself is obviously worn as it leaks at the adjustment screws and I'm sure other places. It's definitely a topend cam but you just couldn't even roll on the throttle without almost killing the engine.

I took it for a spin friday night and it ran alright once you got past 1/2 throttle but it just would not run for anything before 1/2 throttle. It was starving for fuel. DC played with it saturday morning had the pilot right when we started really working on it. I took it for a spin, it would run but it was definitely thirsty just past quarter throttle so we raisedthe needle. Roll on was much better quarter through half but wide open it seemed flat/thirsty still. I played with the throttle, stabbing it and it would stumble real bad the faster I open the throttle. After DC opened up the main, pulled super hard almost to full throttle. Power signed off just at the top of the RPM range. It doesn't have grunt at the bottom but it definitely can get out of it's own way.

I felt we had it pretty close in consideration of leaks and temp/altitude.

[NINJA]

It definitely sounds like you are on the right track DC. Like you said Persistence will persevere eventually

[Curtis-Tecate3]

On my 85 200X I have/had nearly the exact same setup. 12.5-1 Wiseco, Big Al's #2 cam, Bassani pipe 28mm Mikuni, headwork with nice springs, retainers etc and on & on. . I chased jetting for a while and could never get the part throttle right. It would literally scream at full throttle but it hated that part throttle cruising. It would glow the headpipe at 1/4 throttle cruising and would ping if you rolled into the gas at low rpm. I played with pilot jets, needle heights, main jets etc with improvements but still not right. I finaly took some advice and changed the needle itself to a richer one and shazam. No more ping and ran much much better. It still never wanted to idle worth a crap but with the big cam and timing I didnt expect it to. Now before you ask I do not know what exact needle I used but it did make a large improvement. The carb I have is a specific 28mm Flatslide 200X kit from Sudco that came with intake manifold and a few other goodies to make it work. I also had to heat and dent the frame rail to get it to fit better. Are you sure yours isnt resting on the frame and vibrating the fuel into foam...

Good luck,

Curtis.

[The Goat]

dirt running that 30mm I had...the bike was literally sucking so hard into the carb that the airbox was caving in. I was 40 sizes larger on the main and still lean before I just decided that it wasn't worth it....

Good luck to you...but when I would stab the throttle and watch the airbox BUCKLE...I knew tuning that 30 was going to be nigh impossible.

[Dirtcrasher]

dirt running that 30mm I had...the bike was literally sucking so hard into the carb that the airbox was caving in. I was 40 sizes larger on the main and still lean before I just decided that it wasn't worth it....

Good luck to you...but when I would stab the throttle and watch the airbox BUCKLE...I knew tuning that 30 was going to be nigh impossible.

I don't run airbox lids so I doubt there will be that much of a vacuum.

I was running the 30MM, I just had jets available in Indiana..... and I had hoped the 28 Mikuni would work. And work it does, from 1/2 throttle to the moon it's a raped ape.

Now I have jets so I'm just gonna keep toying with it ;)

[BigGreenMachine]

Sounds like a little beast and I'm enjoying you guys picking each others brains in this thread. Sure makes the CRF250R motor in a 200X frame appealing.

[The Goat]

I forgot to mention there was no lid.

The boot running from box to carb would seal itself it would buckle so much.

Good luck with your tuning... takes a long time to go fast.

[BigGreenMachine]

Just wanted to ask if you thought about the CRF150R carb, its a 32mm flat slide Keihin.

[The Goat]

steve

not sure if you saw that article in the scans someone posted a while back...it said that the 28mm was for race only apps...

I'm wondering if that means...kiss your idle goodbye?

[Dirtcrasher]

Hey BGM, no I haven't but thanks for the thought....

I'm still thinking that the butterfly choke is needed esp in the cold weather.

I've been so busy with the 350X headlight guards and staying afloat without a job that I haven't touched the 200X. I just get so tired of heating up the garage (shed) and then trying to do plug chops in 15 degrees - it's just the wrong time of year.

Were getting close to much better weather now so I'll see if the 30MM Keihin RS can work well.

BUT, I'm so glad you posted this, I'm DEFINITELY gonna check into that flatslide and if it's designed for a thumper, I'll bet it could be a well rounded carb for the X. Thank you! :beer:

^ EDIT - Goat, I'd like to see that article, HOOK ME UP!! (or I'll cut your HD guard into macaroni :lol:) Because honestly, that Mikuni 28MM FS I have HAULS ARSE at 3/4 to WOT. I'm not joking, it screws! And it may not ever be well rounded but we only learn from trying different things!!

[The Goat]

http://www.3wheelerworldforums.com/showthread.php?t=94642

took forever to find on the crappy work comp.

it's in one of the ads on the page.

talks about the 28mm specifically.

hope it helps some.

[tanks350x]

I've been thinking about the whole plug chop theory.. Back when I raced at the local short track.. when we first wanted to set up our carbs, there was no such thing as a plug chop, we went 10 laps or so to see what the plugs looked like.. sometimes it would take more that that amount of laps to get an accurate reading.. Granted, your talking apples, and oranges when comparing the 2, Holley, compared to your flatside job... So, what I think you should try, if you already haven't, get it running smoothe, from idle,to WOT,,, put a fresh plug in, and take about 5 to 10 laps on your course, then pull the plug... Because in my opinion, doing an immediate plug chop with a fresh plug is not enough time to get an accurate reading.. Just my thoughts

[Mastacator]

Hey dirtcrasher, have you been able to get back to that mikuni?
I have found myself with the exact same carb, and a fairly modded 200x engine. I've got the same issues, hard to start won't idle and up to 3/4 throttle is no good.
I haven't changed out any jets yet, but I'm hoping to get an idea from you on what ones to put in it to get it closer.

Thanks
Later!

[Dirtcrasher]

^ I don't know what your motor has in it.

But, I ended up putting on my 30MM roundslide and got it so it would start cold and run thru the whole jetting range well. That was at 40 degrees, then at 80 degrees I was far too rich and had to dick with it again.

I only recommend aggressive porting and full race cams for just that - RACING!! They are far too much of a PITA to jet for all conditions. I am seriously considering buying a midrange cam and tossing the race cam.

As far as your situation, I'd obviously bump up the pilot. Not sure if you have a 15 or 2o but I'd grab a 20,25 and 30.

I take it WOT is good?? Is that with or without a lid??

Your needle position can take care of 1/4 to 3/4 throttle.

Listen to it, test it, plug chops and change one thing at a time.

You may get yours, but I could not get a cold start under 40 degrees and I gave up - for now anyway :D

[Mastacator]

Thanks DC.

I didn't realize it before but you are rocking an 86 X right? I read your 20 day build you had going last year today, Sweet ride. I saw the carb on there.
I have a 83 that i just did the same thing, started the build with a tight deadline, and semi-finished it at about 4am the day we were leaving for the sand at 10am. We got it to fire that morning about 2am, but weren't really able to get it tuned. My engine consists of 83, 84 and 85 parts, and an 84 XR200 trans. With that Mikuni carb for the 86 on it.

Its bored to 66mm, 12:1 piston, (that is milled down to 11:1). Midrange Webcam, ported and polished head, lightened flywheel, an oil cooler, Bassani exhaust, and a uni filter.

I've tried running it with lid off and lid on, holes in the lid (like the white bros kit directs) holes covered with the lid on. I think at one time I had the lid off and it "ran" with the choke on. Which from your research on that carb tells us the choke is richening up the mixture. So I definitely need bigger jets. It "runs" with the choke off and the lid on. No matter what I do it stumbles throught the range and doesn't exactly run well at WOT.

So, if your temporary conclusion is correct, that this carb is near strictly for race purpose only, I may have to look elswhere. To which thought I ask, what carb should I go with? I like the flatslide, as the initial startup had instant throttle response, I mean it snapped. and a 28-30mm sounds like a must.

Thanks again.
Later!

[200xfreek]

hey im new, i got jetting questions too. hey umm how do i post pics of my ongoing 200x restoration and where can i post them?

[beets442]

Just kinda skimmed through posts, looks like your on the right track. I don't use flatside carbs but have noticed that they are good for the WOT apps. I was wondering if the slides on a flatslides change pitch like the VM series do.That can cause rich and lean probs too. On the bottom of the slides are marked 2.0, 2.5, 3.0. You can change slides as you jet down, helps with the pilot screw adjustments. Hope that helps.... Beets

[greenhuman]

I have been over at 3wheeler.org for a couple of days discussing the XR200 carb on an ATC 185 engine. There's this dickhead called Ninja there arguing about the size of this carb. Over here they are definately 30mm but old mate says no and I should go back to here.
It now looks like I am banned for upsetting this sooky baby.
Anyway, I have found the best performing carb on my 200X conversions with strokers etc is a standard early model CR80 or '81/'82 ATC250r 28mm Kehein carb with a standard Banshee needle and a 110 main and standard pilot. Idles perfectly, revs like crazy.
I will now go and cry about being banned. Not.

[whyzee]

^ I don't know what your motor has in it.

But, I ended up putting on my 30MM roundslide and got it so it would start cold and run thru the whole jetting range well. That was at 40 degrees, then at 80 degrees I was far too rich and had to dick with it again.

I only recommend aggressive porting and full race cams for just that - RACING!! They are far too much of a PITA to jet for all conditions. I am seriously considering buying a midrange cam and tossing the race cam.

As far as your situation, I'd obviously bump up the pilot. Not sure if you have a 15 or 2o but I'd grab a 20,25 and 30.

I take it WOT is good?? Is that with or without a lid??

Your needle position can take care of 1/4 to 3/4 throttle.

Listen to it, test it, plug chops and change one thing at a time.

You may get yours, but I could not get a cold start under 40 degrees and I gave up - for now anyway :D

Serious lesson learned !!!! I did the same thing about 10 years ago by having a race motor....what a pain in the ass in every single sense of the word. I was so happy to have my mostly stock motor back and just enjoy riding. Insted of rejetting every morning and afternoon, and fussing in between.

Think of how much you just learned though!!! you are an expert now! :beer

[Dirtcrasher]

^ Whyzee, I never realized you had responded but I'm :) that someone else can share the pain of tuning a moderately built motor.....

Even today, it seems like the temperature and humidity play a HUGE roll in how well this thing runs. Aggressive cams and unmatched components make for day by day running conditions. Any CLOWN (such as myself) can merely buy exhausts, cams, pistons, ignition products

In like to find a 28MM RS carb, I feel thats a good match and I honestly think think this cam is just too aggressive for any trail riding

WOT doesn't seem to be affected poorly, but idle to 1/ throttles are definitely a crapshoot based on the day and I ALWAYS run race gas. It screams on top end, but if you want a lower displacement engine to pull and rip out of a tight corner, your tuning has to be SPOT ON!!