85 250r running terrible

[DeePa]

You have probably seen my recent threads on this...

Mods. Bills sectional high rev pipe, DG type 1 Silencer, k & n filter, boysen carbon fiber reeds

I have been playing with jetting all day now. Went from a 148 main and stock coil down to a 142 and aftermarket coil. Ran much better with the new coil.

142 was nice and white, so i went to a 145, still lean, went to a 148, still lean and went to a 150.

Its running like *Edited**Edited**Edited**Edited* through the entire range. It seems to do better when the engine is under load.

What else can i change here? With those mods, do you think i would be much higher than a 150 main jet? I have the stock pilot jet in there with the needle on the second clip.

The bike idles great and is fine up to half throttle. After half throttle is doesnt rev clean and seems to break up a bit. The plugs are never wet, sometimes a little black.

After half throttle the revs dont really increase, just sound nasty.

What is over rev? Since I have a high end pipe....could i be over revving the motor? Is it possible to hit the red line at half throttle?

I am really getting sick of playing with this thing. Next step if i cant figure this out is to get a nice pipe and silencer and start from scratch.

Any advice on what to do now?

Thanks,
Mike

[Jason Hall]

Wow that sounds just like a 250-R that I worked on that had the wrong cdi box on It. I also have a 87 CR125 with a bad stator that does the same thing, It only breaks up on the very top end. If I would drag the brakes on the 125, or short shift It was fine. If I let er rev all the way out It runs like a turd. Check the code on the cdi, I don't know for sure what the code # is for an 85, but Im quite sure an 86 Is HB9. Someone else can probly give you the code for an 85. I know a 86 350X cdi will make an 86 R run, but not very good at all. Ohm out the stator next, that would be my bet If the cdi Is right.

[jason85atc250r]

try a 160 or 170 jet and see what happens. maybe it just needs rebiult real bad my 85 atc 250r ran like that before the last time i rebuilt it.

[ChrisD]

It could be jetting, but if you tried a bunch of jets it could be the stator. Before you spend a bunch of money on a stator, use a timing light and rev it up, see if the light cuts out under rev. It will be the stator. I never had a CDI go up nor a coil. Between my freinds and I we have had 6 stators go over the years.

Jetting is the easiest to correct. I would try it. I also would check your air filter for good flow. However, if nothing changes with any jetting change, then test your stator.

[InPiEcEs]

An 86 CDI will not plug in to an 85 harness. Different plug on the 85. 86 and up are all the same, with the exception of the 85. Exciter coil resistance should be 50-250 ohms, being closer to 50 would be better. Measure between the wire terminal and ground. On the 85 CDI, resistance should be as follows, black/white to green-2-200 ohms, Black/White toBlack/Red-0.2-20, Black/White toGreen/White-2-200, Black/White to Blue Yellow-50-1000, Black/White to Black/Yellow-infinite. Green to Blue/Yellow-10-100. Black/Red toGrn/Wht-0.2-20, BLK/Red to BLK/Yel-20-200.
GRN/WHT to BLU/YEL-10-100.
BLU/YEL to GRN-10-100, BLU/YEL to GRN/WHT-10-100.
BLK/YEL to any-infinite. These came from the Honda manual, and they say to use a Sanwa tester, but any good multimeter will work.
Pulse coil is 50-200 ohms closer to 50 being best.
Any bad connections can make your ignition go funky on you, so check them all good. If it sounds like it's burbling real bad up top, check your plug for being rich, and maybe try going down on the main, unless it looks kinda white. Then it's lean, and you need to fatten up your main jet. Hope this helps, and you get it figured out.

[DeePa]

thansk for all of y our responses.

i just bought an ohm meter/multimeter and timing light.

I dont know how to use the timing light. There is a clip that goes on the plug wire, a b lack clamp for ground, and a red clamp for the pos battery terminal. Where should i hook this one up?

Whats the proper procedure for timing?

I am going to go ohm stuff out now and see what happens.

Thansk,
Mike

[Dusty]

hope you get it runnin good mike.....

[250rAL]

I dont know how to use the timing light. There is a clip that goes on the plug wire, a b lack clamp for ground, and a red clamp for the pos battery terminal. Where should i hook this one up?


Just hook it up to a 12 volt power source. Your car battery will do. That powers the strobe. The black will have to be hooked to the same power source.

[DeePa]

i just ohm'd out the cdi and the only thing that gave a response was the 0/shorts.

i didnt get any other reading by following the manual

the coil and exciter coil ohm'd out perfectly


its a brand new multimeter from radioshack, digital...cost 30 bucks so i hope its not the problem...

is it common for cdi's to go bad?

Mike

[hoser]

I am not sure I understand the question, the mods you listed were installed and the bike ran fine then all of the sudden it started acting up OR you just installed all this stuff and it runs like crap?

You should be checking the integrity of your electrical system and its connections on a regular basis, your system is OLD and no doubt abused, a degraded component will not allow the ignition system to fire every RPM. Funny guys will wadh and wax their ATV's polish chrome etc.after each ride but NEVER check the electrical connections to see if they are dirty, if you have spark I would not blame the CDI at this point, many are too quick to blame the 'black box' I never seen one fail myself. I have seen a few that were replaced and it "fixed the problem" but it you plug in the 'bad CDI' it also ran, all along it was a bad conneciton at the CDI.

[DeePa]

the mode were installed when i bought the bike.

I always thought that it wasnt jetted right...it had the stock jets with all of the aftermarket stuff.

The bike does run, and does have spark. Nice and blue from what i can tell. It breaks up really bad on the top end. When I was running out of gas and the heat of the plug was igniting the gasoline with the ignition switch off, the machine sounded beautiful even though it sounded like it was gonna grenade on me because of the high revs.

I recently put dielectric grease on all connections except the cdi one, i forgot about it.

The bike runs well at idle, but its really starting to break up at mid to high rpms

I have to run it tomorrow because im going riding.

Im sure itll act up but i can get a whole days of riding out of it.

How come my cdi wont get any readings? itll get some but they are in MegaOhms and not even close to where they should be

Mike

[DeePa]

if i go by the manual...

negative on green, positive on black/white I shoudl get 2-200 ohms.

I get nothing...if i switch it up, positive on green, neg on black/white, i get 9.25 M ohms...something cant be right there. the tester worked fine on the coil and exciter coil.

this is the multimeter

http://www.radioshack.com/product/index.jsp?productId=2104114&cp=&origkw=digital+multimeter&kw=digital+multimeter&parentPage=search

Mike

[hoser]

the mode were installed when i bought the bike.

I always thought that it wasnt jetted right...it had the stock jets with all of the aftermarket stuff.

The bike does run, and does have spark. Nice and blue from what i can tell. It breaks up really bad on the top end. When I was running out of gas and the heat of the plug was igniting the gasoline with the ignition switch off, the machine sounded beautiful even though it sounded like it was gonna grenade on me because of the high revs.

I recently put dielectric grease on all connections except the cdi one, i forgot about it.

The bike runs well at idle, but its really starting to break up at mid to high rpms

I have to run it tomorrow because im going riding.

Im sure itll act up but i can get a whole days of riding out of it.

How come my cdi wont get any readings? itll get some but they are in MegaOhms and not even close to where they should be

Mike


Ok thanks, you were running out of gas because it was lean jetting, you were low on gas, your carb was having a problem? The next time that happends turn off the gas and pull the choke.

How does it run at WOT if you remove the lid from the air box, I have found removing the lid is like going 1-2 sizes smaller on the main jet and 1 notch on the needle, your pipe might be looking for more air, the pipe cant work if it cant suck the air into the engine or if your intake 'system' is too restrictive, you might go up 3-4 main jet sizes and lower the clip on the needle one notch before making a WOT pass with the lid off the air box.

Have you tried a jet larger than the 150?

[hoser]

oops forgot....

How are your jetting skills?

I have compiled some great jetting info here http://12.215.122.222/jetting1.htm its great refresher for experienced mechanics and the people new to jetting.

[mart]

Sounds electrical to me for sure.

[Dammit!]

Check your float level too. My Z used to do something similar and that was the cause. Float level was low.

[NewOldSchool]

my trimoto does the same thing, i finally got desperate and i blew into the gas tank, it ran alot beter for about a second or two then it started its S>H>I>T> again. somebody told me it was my reeds and just to turn them over....it ran great until i poured some bad gas in it on accident.....thas when i sold it

[DeePa]

this still doesnt explain why im not getting any reading on my cdi.

im going out there in a bit an dill ch eck the float level

I dont get how it runs but i cant get any readsing on my cdi

i have never tried anything higher than a 150 main jet


mike

[hrc85250r]

CDI'S are funky to test and rarely go bad unless somebody does something stupid to the system. completely tear your carb apart and clean it and make sure your intake boot isnt crack and there are NO airleaks. other than that jet it more. check your reeds too. they may be crack or some pieces are missing, that will lean it out. timing isnt an issue because the flywheel is keyed and timing on a 250r is not variable in any way. check your spark plug boot connection and boot-to-plug connection, make sure its solid, and make sure the spark plug wire isnt loose in the coil. if still sketchy, find a cdi you can borrow and plug it in and try it, i gaurantee that isnt it though.

[DeePa]

the tube from the airbox to carb does have some cracks where it fits around the carb...

could that be messing me all up?

im pretty sure the reeds are ok but ill check them anways.

Time to go to work

If i have any questions ill be checking in

thanks for all of your help so far

mike

[hoser]

Its just my hunch but I think your pipe is asking for more than your giving it.

Try the bigger jets.

Try the air box lid.

Cracks in the tube from the airbox to the carb mean its time to replace the parts that are cracked I would not want it to crack open whilst I was out running down a dusty trail and suck all kinds of dirt into my engine, as SOON as one finds any parts like that degraded they should be replaced ASAP so we dont create other problems for ourselfs in the future.

I agree if the CDI is working dont worry about the readings your taking, I was told long ago the only way to test a CDI properly requires expensive equiptment thats why dealers dont buy the tester its cheaper to buy a replacement CDI and swap in to see if its bad.

Kudos on putting the dielectric grease on all connections how ever some times just putting it on them is not enough sometimes you need to clean the connection, over time where the connection meets the wires moisture is wicked up into the wire itself and the wire will corrode I have seen this happen on connections that looked brand new, connections that were greased at the factory so incase your still having problems later done rule out the connection thing..

[Erics350x]

if the cdi doesnt pass the test per honda , why are we still looking for a problem? just because most of use havent seen a bad one doesnt mean it isnt bad.

[DeePa]

i took it riding today with the 150 main and kept the air box lid on. Taking the lid off didnt do much. It would run good up to half throttle/3/4 throttle if i gave it gas really slow. if i punched it, it would break up at any throttle.

Does that mean its getting too much gas? is 150 too small for a pipe and filter?


It seems that right when its about to get on the pipe, it breaks up. Could the pipe be clogged with something? Would it still run halfway decent if the pipe was clogged?

Mike

[InPiEcEs]

Does it sound like it's missing, or does it sound like it's burbling(4-stroking) when it breaks up. I would maybe check every connection you can for the ignition. Dirty connections make your ignition do funny things. Also, a coil that makes good blue spark when yoou check it may not be so hot when the rpm's go up. The info I gave you from the Honda manual is right, but like people said, it is easier to swap in a good one to check the cdi. In all honesty, your last post makes me think you need to go richer on your main. Try a 160 main and see what happens. I know it's a big jump from the 150, but try it. If it runs better, but ends up on the rich side(dark brown to black plug), then work your way down. If it runs better, but falls flat near the top, check your plug for being lean. You may have to mess with your needle clip postion a little for the midrange as well. Here is a link to a spark plug chart that might help.

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

I like to err on the rich side on my jetting and work down, because plugs are cheaper than an engine rebuild. Keep us posted.

[hoser]

Does it sound like it's missing, or does it sound like it's burbling(4-stroking) when it breaks up. I would maybe check every connection you can for the ignition. Dirty connections make your ignition do funny things. Also, a coil that makes good blue spark when yoou check it may not be so hot when the rpm's go up. The info I gave you from the Honda manual is right, but like people said, it is easier to swap in a good one to check the cdi. In all honesty, your last post makes me think you need to go richer on your main. Try a 160 main and see what happens. I know it's a big jump from the 150, but try it. If it runs better, but ends up on the rich side(dark brown to black plug), then work your way down. If it runs better, but falls flat near the top, check your plug for being lean. You may have to mess with your needle clip postion a little for the midrange as well. Here is a link to a spark plug chart that might help.

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

I like to err on the rich side on my jetting and work down, because plugs are cheaper than an engine rebuild. Keep us posted.


Here is another one http://12.215.122.222/sparkplug.htm
Follow the links.

[Jason Hall]

My bet Is still on the Stator, or a bad connection. My 125 does the exact same thing. If you just romp the throttle It will spudder like the jetting Is way to rich. If you ease on the throttle It will rev clean until the very top of the RPM range, when the load Is gone. Wiggle the wires when you ohm the stator, you might see a change only when the wires are bent.

[DeePa]

how do i ohm the stator and what values am i looking for? ro what page is it on in the manual?

Mike

[Mosh]

seen a lot of water get in stator covers and gum up the works. you may want to pull it off and see if it is wet in there or all rusty and stuff. a little rust on your pickup can cuase a weak output signal cuasing your bike to break up under high rpms.

[InPiEcEs]

Mosh has a good point. Seen it myself, too. Anyway, If you have a Honda manual for 85-86 R, Electrical is section 15. For the exciter coil, which is in the stator, Remove the tank, and disconnect the Black/Red wire. Ohm from that to ground. Reading should be 50-250 ohms. Quite a range if you ask me. For the pulse, or trigger coil, again, tank must be off, and disconnect the connector. Measure between the leadds that go TO the pulse coil. They say 50-200 ohms. Again, quite a range. The pulse coil is the little one that sits outside your flywheel, and triggers your spark. If that has a weak signal, it can cause break-up. Like Mosh said, definitely pop the stator cover and check the pulse coil. You will notice a rectangular raised section on the outside of the flywheel. If this is looking quite rusty, clean it up carefully. You should remove the pulse coil and check it for rust if you see any on the flywheel. That rust can cause havoc sometimes. Its funny that they don't give an air-gap for the pulse coil, since it can move a little once loosened up.

[atcsteve]

Fix the air leak,then take off your silencer and see how she runs.If thats not your problem,do the carb right.If your getting spark correctly up to half throttle,then probably not a cdi or stator problem.Sounds like a fuel problem or pipe restriction to me!! Good luck.

[DeePa]

OK...update time

I havent bought the airbox tube yet, im working on it.

I took the silencer off and it seemed to be the same, except so *Edited**Edited**Edited**Edited**Edited**Edited**E dited* loud it hurt my head.

I took the pipe off and it isnt clogged at all. Poured some gas through it and it was all set.

I took the stator cover and it was dry as a bone, but there was rust on the flywheel. I just bought a puller on ebay so i can look underneath it. heres a pic of it.

http://members.cox.net/deepa20/13.JPG

And heres a picture of the little thing next to the flywheel

http://members.cox.net/deepa20/14.JPG

I ohmed out the exciter coil and it was 138.

I ohmed out the pulse coil and it was around 114.

I took a picture of the ports and piston...is that too much carbon?

http://members.cox.net/deepa20/11.JPG

I noticed when the silencer was off that there was some wet spots on the fenders where the pipe was. It was gas. Is it bad that gas made it through the pipe? Does that mean i am running rich? I want to get all of this electrical stuff sought out before i go buy more jets.

Mike

[Mosh]

well i am out of ideas for you. the ports look like some one was runnin really crappy 2 stroke oil . just go back over the basics. compression, . i know everyone was tellin you to go richer on the jets. have you tried going leaner? what is the leanest jet you have tried?

[DeePa]

the leanest i have tried was a 142 and that was really lean. I need to get a pic of the spark plug i just pulled out of it. Ill do that a lil later on.

I used blue marble for the last 6 tanks or so, but ran out. I went to bennys and bought some halvoline 2 stroke and mixed it at 32:1. I was running 50:1 before.

Should I wash the engine out with that stuff you guys have been mentioning
?
what should i do about that rust on the flywheel? Pull it off and se whats under it?


Mike

[Mosh]

well if there was rust under the flywheel,you would have lighting problems. the flywhell looks real good. tell me though,do you see oil running out of the crank seal behind the flywheel?make sure that the little black pickup box has about a 17thousands gap when the raised portion of the flywheel passes it.just roll it over till the little metal tab is under the pickup coil and check it with a feeler gage.that is what drives the signal to the coil. you did check your plug wire and boot right? if you do see oil coming out the crank seal and dripping down the case behind the flywheel,then you could have a bad crank seal.basically i am out of ideas. sometimes i wish i could see these problems in person. it is very hard to diagnose problems over the computer or phone.i have read this entire post 3 times,and it reminds me of a lt 250r that was jetted way to rich.you might want to go back to your stoock jet and needle and clip posistion and start all over again. sometimes it is best to start at the beginning.it wont hit the top end.here is a dumb question.is your air filter over oiled? too much filter oil will cuase this problem too.

[DeePa]

i have seen something liquidy from the crank seals. I couldnt figure out exactly what it was. It didnt look like gas/oil mix, it didnt light on fire, and theres was two or 3 drops of it. This time when i opened it, there was nothing in there at all.

How can i test for a bad crank seal? Ill go take a picture of a plug and check that gap.

Mike

[Mosh]

to check for an air leak, you have to get a rubber expandable freezeplug and put it in the exuast on the jug and tighten it down.then you have to fab some sort of plate to put on the intake side of the cylinder.it has to be sealed too. then you fab a vacumn fitting to screw into your sparkplug hole. once everything is sealed,you apply 20 inches of vacumn with a vacumn pump and it should hold at least 1 hour without bleeding off. it is kinda complelex to explain but easy to do once you see it done.you can also leave the reeds and intake boot attached and use a rubber freezplug where the carb gets clamped in, instead of fabbing a block off plate.

[DeePa]

here are the plug pucs...some are full chops with varios jets. The first one is the current plug i used to ride over the weekend.

Mike

[3leggeddog]

by the carbon build up,and the plugs i would have to guess your a bit rich.it may not be all in the main jet.lean everything up a little and run her.if you need jets,i got a arse load.you are welcome to any of my doubles.let me know,i'll send a few out

[Pete]

did you ever check the reeds? I know you said you were, but never mentioned if they were OK or not.

[hoser]

by the carbon build up,and the plugs i would have to guess your a bit rich.it may not be all in the main jet.lean everything up a little and run her.if you need jets,i got a arse load.you are welcome to any of my doubles.let me know,i'll send a few out


Correct, and you jet from bottom to top http://12.215.122.222/BillGivensjetting.htm

[DeePa]

I have no idea what happened, but it runs great.

I took the pipe and silencer off and cleaned them up.

Changed the main jet from a 150 to 145

Put a new floatvalve and air screw in the carb.

Cleaned and oiled my K & N

Changed plug to a BR8ES

Cleaned up flywheel

Checked reeds and rotated the cage 180 deg.

Put stock coil back on

Put dielectric grease in all electrical connections and pushed them and rotated them to get a good conection

I guess it was just a combo of everything.

The plug is a nice brown color too.

The pipe has a really consertavie hit which is good for trails

Thank you very much for all of your help. I really appreciate it.

Mike

[hoser]

Its great you got it running again but you did so much at one time when it happens again you have no idea what the problem actually was, its best to do things one at a time then test the results of your changesto verify its out come..

Something you might want to know about K&N http://12.215.122.222/K%26N.htm follow the links at the bottom too.

[OldSchoolin86]

Please don't turn this into an air filter debate. Any time an opinion about air filters are tossed in the entire topic is lost.

Good news on the R DeePa, the list looks like a bunch of stuff that should be done to many machines.

[Dammit!]

Correct, and you jet from bottom to top http://12.215.122.222/BillGivensjetting.htm

That's interesting. The way I was taught is pretty much the exact opposite (top to bottom). I don't have time to read all that right this second but I'll be sure to check it out soon.

And people wonder why jetting is confusing. :lol:

[hoser]

That's interesting. The way I was taught is pretty much the exact opposite (top to bottom). I don't have time to read all that right this second but I'll be sure to check it out soon.

And people wonder why jetting is confusing. :lol:

All the circuits of the carb over lap each other,

http://12.215.122.222/carb%20tuning_files/graph.jpg

so each affect each other, when you start your engine and it is ideling your starting on the bottom, as you warm up the engine and start to ride your progressing to the top so you jet from bottom to top, if your mid range is painfully over rich it will affect the plug color of your WOT plug chop, same goes if you were lean in the mid.

[hoser]

Please don't turn this into an air filter debate. Any time an opinion about air filters are tossed in the entire topic is lost.

Good news on the R DeePa, the list looks like a bunch of stuff that should be done to many machines.

Sorry I am not trying to start a filter debate, I could care less what filter anybody uses, just trying to help and share real life experiences, some lessons involved in gaining the experience was paid for by me, some was paid for by my friends, either way I hate to see others learn the hard way.