Hungry for Spark plugs

[Mack]

Does anyone have an idea why factory jetting would foul so many plugs?

I took my 84R to the Badlands off road park in Attica, IN on friday. Pretty cool place to ride and my R ran great all day with one annoying reoccurrence. I went through 6 plugs in 8 hours. I started out with stock pilot and a 138 main that id put in earlier in the week due to lean plug chops. The 138 gave me a black read but I didn't have a 135 so I went with it. Everything was going well until I took on a pretty big hill and my trike bogged out at the top and died. Other than a cracked front fender :cry:(pissed) a bent clutch lever fouled plug and a panicking run down the hill, all was well. I changed the plug and rode back to the truck and jetted the main back down to a 130. The rest of the day I was good on the hills as long as I didn't open it WOT or i'd foul the plug.

A 130 is the factory main and my trike is all stock. I spent the rest of the day changing plugs every hour or two. A few times I would shut it of to take a break and when I started it back up and took off it would bog down and die with no start until I changed the plug. another time, I was drag racing my buddy on his lt250r and I got it revving real high in first and it just crapped out and died with another fouled plug. To me this indicates rich at 3/4 to WOT but why would that happen with factory jetting?
My brother suggested that the timing may have delayed a bit over the years? I am also running NGK BR9ES which all 3 Honda shops in my area have recommended for my trike but another member on here said to run BR8ES.

All in all it ran well and being my first real ride on three wheels (been on 4 all my life) I actually like a lot of things about trikes better than quads. My only dislike is those steep hills that are rutted out by quads at the very top and pretty much serve as a deathtrap to a center placed front wheel. I just wanna get this thing dialed in for the next trip. Any suggestions or insight regarding timing or any other ideas would be appreciated. Mack

[jmax857]

Is it burning clean or does the exhaust stink? Any black sploog coming out the exhaust? What oilfuel ratio arr you running. Are you using quality oil?

[Mack]

I'm running Klotz at 32:1. The exhaust smells like the klotz but it smokes moderately and yes black oily sploog consistently seeps from the exhaust. It doesn't blow out or anything, but the end of the silencer is always wet with it. What would this indicate? I just thought that was typical of a two stroke.

[hoosierlogger]

I would cut back on the oil a little bit. Maybe go to 40:1

[just ben]

kinda sounds like a weak coil,even with too much oil you shouldn't be going through a plug every hour

[jmax857]

Do a resistance test on the coil. Does it have a nice blue spark? Are tbe plugs gapped properly?? Stinky exhaust and an abundance of black splooge would indicates a bad clutch side crank seal. It would be obvious and if wouldnt run top notch either. 32 to 1 is not too much oil espefially for a air cooled r

[bkm]

Have you performed a compression test lately?

[Thorpe]

Trans oil still full? (crank seal going?)

[Jason125m]

My money is on the coil. You would be able to tell if crank seal is gone. Oil doesn't burn white... Lol.

[RIDE-RED 250r]

All good advice, and I will add that most of the time, factory jetting for just about anything is going to be safely rich to begin with. That has been my experience with multi-cylinder sleds, trikes, bikes and on and on.

If your coil, trans side crank seal and comression all check out OK, it sounds to me like you just might need to drop the needle one notch and step your pilot jet down 1 size.

Don't go messing with sparkplug heat ranges to try and address what is actually a jetting issue. That is a VERY common misconception and mistake. The heat range rating of a sparkplug only indicates how quickly it will transfer heat from combustion into the cylinder head, thus (in tandem with jetting setup) regulating combustion chamber temps to a degree. Yes, it can be a band-aid to an improper jetting setup, but it is not the proper solution and could end up costing you a top end on a long pull in warmer weather. The BR9's will keep you safer with a long pull.

After reading your post a second time, it seems that it is responding to jetting changes to a point. Check your trans oil and make sure it's not mysteriously low. If that checks out, then I would say try some jetting changes, mainly with the needle position and pilot jet. If it is unresponsive to jetting changes then start troublshooting other components.

It's kind of putting the cart before the horse to jump into all the other possibilites if it is responding to jetting changes. You check all that other stuff if it is unresponsive to jetting, or the jetting jumps all over the place and is unstable. That would indicate problems with ignition and/or crank seals....

[Thorpe]

My money is on the coil. You would be able to tell if crank seal is gone. Oil doesn't burn white... Lol.

Did I miss white smoke somewhere in the description? I caught constant sploog out the exhaust...?

[Jason125m]

No, he didn't bring it up, but I would assume he would notice IF his R is smoking white ( which it isn't, i hope? )
That's how I came to the coil conclusion.

[Thorpe]

Gotcha....

[Micahdogg]

All good advice, and I will add that most of the time, factory jetting for just about anything is going to be safely rich to begin with. That has been my experience with multi-cylinder sleds, trikes, bikes and on and on.

I agree with this. I've also noticed the needle making a dramatic affect on spooging. So I would also agree in trying lean the clip.

I would also use a BR8ES with 50:1 premium. I've used Klotz quite a bit and it is great, but gummy and will clog your carb easily (semi-regular riding for me meant cleaning the carb twice a year). Just make sure your carb is clean to begin with, but otherwise I've had no performance problems with Klotz. Also if your compression is around the 100 psi range, you will eat plugs often, but the machine will otherwise run well.

[Mack]

First off, Thanks for the abundance and variety of replies.

To clear a few things up, My trike is not smoking white. It does smoke consistently but its a blue smoke and just smells like klotz. Also, I am assuming that a BR9ES is gapped properly out of the box but please correct me if I'm wrong because i've never heard of gapping a new plug to a specific tolerance before screwing it in. I haven't had a chance to check my tranny fluid but I will first break I get. Finally my compression is high if anything, 185 to 190 on a craftsman gauge and 180 on a Harbor Freight gauge.


Do a resistance test on the coil. Does it have a nice blue spark? Are tbe plugs gapped properly??

Last time I checked, I had great spark. How exactly would I do a resistance check on the coil? Am I simply measuring ohms from input to output or something different, and what kind of reading should I come up with in a properly functioning coil vs a weak one?


After reading your post a second time, it seems that it is responding to jetting changes to a point

Ride-Red, It does seem to respond to main jet changes. I haven't messed with the needle or the pilot but I've been thinking my pilot is rich for awhile now. Is there any risk in leaning out the needle? Especially since its getting cold (mid 30's to low 40's here)

Last question, Would it hurt to reset the timing since its probably never been done since it left the dealership in 84?

[Micahdogg]

Definitely good on the compression. Next up, check that tranny fluid to rule out the trans fluid burning.

As for the smoking thing, your bike doesn't need to smoke much at all and it's ok if your insulator has white portions even after riding for awhile. So don't be afraid to lean your premix. Leaning the premix will make you even richer in air/fuel though - so don't be afraid to lean the jetting again. You won't blow anything up by leaning the needle. In fact, you won't blow anything up if you just go a size or two on the main at a time.

[Mack]

Update: Tranny fluid level is great. Any details on testing the coil would be great. If coil checks out I will commence to jetting.

[Micahdogg]

I can't offer any help there. I usually just kick it with the plug against the head and make sure it's throwing a decent spark (not some little flicker of a spark). Then if the timing is set correctly, I call it good.

[oscarmayer]

i would recommend cleaning the carb from ground up. as mentioned Klots can gum up a carb. it could be as simple as a clogged hole or jet. Also as mentioned you may be running to much oil on your setup try going to a 40:1 and see how that goes.
Your a 2-stroek there is no timing chain to adjsut so don't worrie about timing. it is handled by the CDI and pickup. Do check to make sure all that is tight and in order.

[RIDE-RED 250r]

Ride-Red, It does seem to respond to main jet changes. I haven't messed with the needle or the pilot but I've been thinking my pilot is rich for awhile now. Is there any risk in leaning out the needle? Especially since its getting cold (mid 30's to low 40's here)

Last question, Would it hurt to reset the timing since its probably never been done since it left the dealership in 84?

The 3rd gen 250r's have fixxed ignition timing and is not adjustable, so I would assume your 2nd gen 250r probably has fixxed timing as well. There is no need or way to adjust it, so timing should not be your problem.

As to jetting, I run my big bore at 32:1 on Sunoco 110 and Maxima 927 and it runs it happily all day long and never biffs a plug. I don't mean to open the "what oil/what ratio" can of worms here, but what you have is a jetting issue, not a premix ratio issue. These engines were built to run at 20:1 reliably. Running leaner ratios is safe and acceptable with todays better oils but be careful not to go too lean. That premix ratio is what keeps all of your bottom end bearings lubricated and adequately cooled. If you do a little looking around, you will find the most reputable names in the business highly recommend a 32:1 ratio with modern high quality premix oil. Micahdogg is right, leaning premix ratio will richen fuel mixture. But like I said, you are also reducing the amount of oil getting to your crank bearings, lower rod bearing, wrist pin bearing and cylinder wall. Carefull with how lean you go...

So, your trans oil checks out OK... Time to start making jetting adjustments. It sounds like most of your problem is in the low end and maybe a little bit of midrange. I would start leaning the pilot jet 1 size at a time till you get good performance without showing signs of a lean condition. Once you get that dialed in, see how the mid range acts and adjust the slide needle as needed. After both are satisfactory, do plug chops with a new plug for each throttle range, (1/4 or less for low, 1/4-3/4 for mid and 3/4 to WOT for high). Each of these plug chops will tell you how each circuit (pilot, needle and main jet respectively) is running.

My money says you are just one or two sizes too rich with your pilot jet.

[Micahdogg]

These engines were built to run at 20:1 reliably.

It has always been my impression that the big four put "20:1" stickers on everything as more of a disclaimer to avoid people blowing up their engines. But I've never known anyone that actually had luck running 20:1 reliably unless it was a 80cc or 125cc that was raced. Admittedly, for years I mixed at 32:1 though, but then I started using good oils.

[RIDE-RED 250r]

That's a valid point Micah, just like factory jetting specs tend to be safely rich.

I'm not saying you are wrong or anything, just pointing out that less oil gets to the bottom end when you lean the premix ratio. :)

[bkm]

Its probably just as good of a chance that the old round slide stocker carb has seen better days and was probably junk ten years ago.

[jmax857]

It can run 32:1 even 20:1 reliably if jetted properly. with modern synthetic oil 20:1 is not necessary but it shouldnt be an issue.

[RIDE-RED 250r]

Its probably just as good of a chance that the old round slide stocker carb has seen better days and was probably junk ten years ago.

Good point BKM. Definitely a possibility if he can't get it to jet in.

[Mack]

Thanks again for the response fellas.


As far as spark goes the 81 - 84 250r has an adjustible stator there are three bolts that hold it on and you can advance and retard it the stator holes are slotted. I use 8r plugs in all 4 of my 250rs.

I will CHECK the stator to make sure the timing marks line up and adjust if necessary.


Its probably just as good of a chance that the old round slide stocker carb has seen better days and was probably junk ten years ago.

The stock carb seems to be in good shape and has been cleaned several times since I bought the trike (every time i've changed the jetting). However I did pick up a PJ34 last week off a 89 trx for 60 bucks and it appears to have seen minimal use. The guy has had it sitting in the gage for years after he went with a bigger carb for the quad.

I will probably up the premix to 40:1 because I see no harm in it and it does smoke a decent amount at 32:1.

If anyone can suggest a good jet range to start playing with for a PJ34 and stock setup, I would appreciate it. If i'm gonna play the trial and error jetting game I'd might as well do it with the new carb.

You guys are awesome. Without this forum I would've went with the original owners recommendation of lucas oil 80:1 lol

[RIDE-RED 250r]

Thanks again for the response fellas.



I will CHECK the stator to make sure the timing marks line up and adjust if necessary.



The stock carb seems to be in good shape and has been cleaned several times since I bought the trike (every time i've changed the jetting). However I did pick up a PJ34 last week off a 89 trx for 60 bucks and it appears to have seen minimal use. The guy has had it sitting in the gage for years after he went with a bigger carb for the quad.

I will probably up the premix to 40:1 because I see no harm in it and it does smoke a decent amount at 32:1.

If anyone can suggest a good jet range to start playing with for a PJ34 and stock setup, I would appreciate it. If i'm gonna play the trial and error jetting game I'd might as well do it with the new carb.

You guys are awesome. Without this forum I would've went with the original owners recommendation of lucas oil 80:1 lol

BAD JUJU! Smart of you to run more oil than 80:1. I don't care what promises are made on the bottle, 80:1 is way too lean in my opinion and would NEVER run anything I own that is premix on a ratio that lean.

I was just thinking again about what Micah and I were discussing earlier in this thread regarding oil ratio having an effect on jetting. Go with me on this for a second...

Honda recommended a 20:1 fuel/oil ratio and established baseline jetting to work at that premix ratio.

Now, by cutting the fuel/oil ratio down to 32:1 that very well could richen your fuel/air mix to cause your rich condition down low that is giving you the problem of eating plugs. If you drop to 40:1, that will richen your fuel/air mix even further, excentuating the problem.

If it were me, I would get the jetting dialed in at 32:1 and see how it runs first. Then go ahead and jump to 40:1 if you still feel compelled to do so. Take it one step at a time. By establishing good jetting now, it will be easier to make small changes to compensate if you want to change premix ratios later.

As to your baseline jetting question for the PJ34.. I have no experience with the ol' Air-Hammers, but if I were to dig in, I would try to jet it safely rich and work it down from there. I would probably initially try a 140-142 main jet with a 42-45 pilot with the slide needle clip in the middle groove. There are guys that run the Air-Hammers here and I'm sure they would know better off-hand a good baseline jetting setup for that carb on that engine...

[jmax857]

BAD JUJU! Smart of you to run more oil than 80:1. I don't care what promises are made on the bottle, 80:1 is way too lean in my opinion and would NEVER run anything I own that is premix on a ratio that is pelled to do so. ...

It could run on 80.1 no problem yamaha outboards run 100:1 premix and they last just aslong or not longer than a 50.1 outboard engine. Im not saying we need to mix our air cooled 250rs 80:1 but it realistically would not be a problem with the right jetting and the proper oil.

In fact if you look at opti max outboard engines and figure out how much oil you burn in comparison to fuel its something like 100:1 at wot. And at idle as high as 200:1

[RIDE-RED 250r]

Yes, but I would venture a guess that those outboards are specifically designed to run at 100:1 safely. It could be a difference as simple as more/bigger weep holes in the crankcase for more oil to seep into the crank bearings, longer oil slits on the lower rod bearing housing, etc etc. Just because the modern Yamaha outboards and Evinrude ETECs can get by on so little oil doesn't necessarily mean older machines can.

I do agree with you though on proper jetting being key. But I garantee, on our old wing-dingers, the bottom ends won't last nearly as long on such lean premix ratios. Especially if run halfway hard the way they were intended to.

But I will alter my initial statement slightly.. I would never run something that lean on premix except in a case like a modern outboard that the manufacturer calls for ratios that lean.. ;)

[bkm]

I would see where the PJ is at with the stock jetting and go from there. That will create a baseline to start with.

[fabiodriven]

I've got a couple of things to add here.

First of all, there's a lot of talk here about what mix ratio to run the bike at. Obviously the ratio is important, but it's not the reason the bike is fouling plugs. The difference between 32:1 and 40:1 is not going to effect how the bike runs enough to notice, and it's not going to be the cause for fouling plugs. I have been riding for 20+ years and when I mix my gas I just toss a guesstimated amount of oil into the tank and go. Now, I know that's not the right way to do it and I'm not recommending this method for anyone else, but I will say this- My Tecate ran great the entire time I had it ON THE FACTORY NIKASIL from 1985. It's in TecateDan's hands now and was tested at 195 PSI of compression last week. I had the same spark plug in that bike for over 3 years. My point being here, the small jetting change you will net from your premix ratio is not significant enough to cause the problems you have.

I like the idea of looking at the timing. It's not going to hurt anything and it's a good idea just to rule that out.

I'm not backing this theory 100%, but I'm kind of at a loss here as to why you would be eating so many plugs. I would suggest "cooking" your exhaust to get any excess buildup of carbon and oil out of there. It could possibly explain the abundance of oil leaking from your headpipe and also the lack of air flow through your motor (causing the wet plugs). Again, this may or may not work for you, but it's only going to help things. If you're not familiar with cooking off your exhaust, look here- http://www.3wheelerworld.com/showthread.php/149971-Carbon-removal-from-pipe..

[jmax857]

Also check the reed valves its simple enough to do and could also be a culprite.

[Mack]

Also check the reed valves its simple enough to do and could also be a culprite.

Now that you mention it, I had the reeds out a few weeks back and noticed A decent gap between the petals and the cage. I called a mechanic at my local dealer and he said there should be a pretty small tolerance ( .001 - .003 or so). I had somewhere around .015". I flipped the petals and got down to .004 or .005 and figured I would be ok. I actually completely forgot about that until now because the petals were in good shape visibly.

Obviously, I'm no expert but if the gap is too large, at idle, the slide would be nearly closed restricting the airflow needed for the excess fuel being drawn through the reeds and cause over wetting the plug. Let me know if im on the wrong train of thought and if these tolerances sound correct based on your experiences.

I will proceed to replace the reeds regardless because they're pretty cheap and Then I can eliminate that and move to proper jetting with my new carb. Does anyone know if the little brass plates that hold the reeds to the cage come in the package with a new set of reeds because I remember one of my plates is bent a bit and would like to rule that out as well.


I would suggest "cooking" your exhaust to get any excess buildup of carbon and oil out of there.

I did cook my exhaust with a propane torch in the end for several hours a couple weeks back and then cooked it from the other end for a few more hours. I did it until it would hardly smoke and then blew it out with the compressor.

Thanks again guys. All great ideas thats why i'm here. Mack

[Micahdogg]

I don't think there should be any gap. Replacing them is a good start. I just replaced some stock ones in a cr125 that looked good and was blown away at the difference in performance. It is a friends bike and I absolutely hated it, but after superstock boyeson reeds went in, it is now quite tolerable. I definitely was not prepared for that kind of difference with no other changes.

[jmax857]

If your reeds are crap it will give you hell trying to jet it.

[Mack]

Just out of curiosity, I assume that the reed petals will settle in the open direction over time and leave you with a gap. (based on what my petals looked like). How often do reeds need replaced, or flipped? Also, Is the stock cage fine to use or is there something more reliable out there?

[Micahdogg]

Yeah, they get warped from constantly opening in one direction. Sometimes they will chip at the ends or crack. Flipping is a band-aid so I would only suggest doing it once if you have to. Otherwise, it's just periodic maintenance and depends on how often you ride. I don't check reeds very often unless I'm having a problem that I need to chase down. If your cage isn't damaged and the new reeds lay nice and flat on it, i would just reuse what you have. I also don't get too fired up with dual stage or carbon fiber reeds....2 strokes are simple and I like to keep the reeds simple.

[RIDE-RED 250r]

Reed petal life varies. In general, most carbon fiber type reed petals will begin to flake and chip on the ends before developing a set and not laying flat on the block. I have had some do that within 3 hours run time. Make sure and run stops if you can. Some reedblock setups can't be run with stops. I don't even know if anyone offers old school steel petals anymore... They are pretty much a thing of the past.

Basically, it's a good idea to inspect your reeds seasonally at minimum. Like I said, some last longer than others....

[Mack]

Make sure and run stops if you can. Some reedblock setups can't be run with stops.

What exactly do you mean by stops?

[RIDE-RED 250r]

Reed stops.. The metal pieces that sandwich over the reed petals to keep them from over-extending. Some reedblocks have them, others don't. If your reedblock has them, it's a good idea to keep using them IMHO.

[Mack]

Gotcha. Thanks Man

[Dirtcrasher]

Take the airbox lid off and see how it runs at 32:1. If it's worse, you KNOW your too lean.

What elevation were you riding at or is that the norm?

[82 250r]

Mack, if you have a 34mm PJ, use it. Don't waste another minute on the round slide pe if you have a pj.
Clean it out as already described then jet it from the factory. 42 pilot, 145 main, middle clip. This is a starting point.
If it were mine, i would look for rust and corrosion under the flywheel, stator and ALL wire terminals/connecters. Many carb issues turn out to be electrical problems.
The wet silencer and spooge on the pipe indicate a miss. The miss can be caused by an electrical or carb issue. It's good to eliminate electrical before spending time on jetting.

Marc

[Mack]

Mack, if you have a 34mm PJ, use it. Don't waste another minute on the round slide pe if you have a pj.

As soon as I get the chance.

Also, I gave her a bath today and happened to snap a few pictures so I figured i'd throw those on here too.

158698
Before the bath

158696
The aftermath of that big hill I described in my first post on this thread. Major bummer

158697
And to end on a happy note, my New to me PJ that I scored for 60 bucks

[Mack]

Oh and while I'm thinking about it. Do any of you guys have experience with the v-force 3 setup vs running boyesons on a stock cage? If so could you give me some details or opinions and let me know if the performance of the vf3's will justify the price of the whole setup vs a less expensive boyeson petal replacement.

[jmax857]

I have picked up boyesons for around 20-30 bucks and they usually do the trick just fine. The v force reeds are a good product and work. But them alone wont make much of a difference. If your going to keep your stock expansion chamber and air filter setup then the v force is kind of a waste of a few hundred bucks. If your planning on trying to push as much hp out of your r as you can get the vforce and compliment it with other performance mods.

[Micahdogg]

All the VForce stuff is good and works (unlike Boyeson Rad Valves, IMO). For most applications, just replacment Boyeson cheapo single stage reeds on the stock cage is my go-to solution. This would probably be fine for your R. (and like $200 cheaper!)

[Mack]

Mack, if you have a 34mm PJ, use it. Don't waste another minute on the round slide pe if you have a pj.
Clean it out as already described then jet it from the factory. 42 pilot, 145 main, middle clip. This is a starting point.
If it were mine, i would look for rust and corrosion under the flywheel, stator and ALL wire terminals/connecters. Many carb issues turn out to be electrical problems.
The wet silencer and spooge on the pipe indicate a miss. The miss can be caused by an electrical or carb issue. It's good to eliminate electrical before spending time on jetting.

Marc

OK, educate me on the negative effects of rust on the flywheel. Here are a few pictures.

158717158718158719158720

As you can see, the outside and inside of the flywheel are slightly rusted but from what I can see the stator is dry. There doesn't appear to be any oil behind the flywheel or anywhere in this side of the case and I have good compression so I'm pretty confident my crank seal is fine. My brother should be in town with his flywheel puller this weekend so I can check timing.

I'm really just wandering what rust on the flywheel indicates?

[82 250r]

That has got to be the cleanest 2nd gen flywheel i've ever seen. You may be ok in that regard.
It is common for water to get into the stator cover and destroy everything there. Rust, (even rust dust) will effect the magnetic field causing a weak spark which results in a miss.
If it ran good before, I would not mess with the timing either.

Check the CDI, spark plug boot, and coil terminals for corrosion and then install that PJ.

Marc

[teamboaty]

Im not sure by any means but I used to run KLOTZ because I LOVE the smell of it. I ran it at 100:1 and that it what the bottle said to do. I NEVER had a problem and to all you nay sayers Ive also NEVER friead a motor EVER.