Jump to content
Sign in to follow this  

02 cr250 fouling plugs???????

Recommended Posts

hi there. recently my cr250 has been fouling 2-3 plugs every 3 ur four hours of riding. i have a small chip in my flywheel side case that i beleve was letting some water to get it.and ive been riding threw alot of puddles an such. Can water getting in your flywheel cause your bike to die and not start until a new plug is introduced???? i alaso have stock jetting the bike has lottsa power but will load up a bit when going slow for a while or goig down hills. i was blaming poor jetting. and am going to try a jd jett kit. anyone have any suggestions or know if some water entering the flywheel side could foul a plug. thanks alot cheers!

Share this post


Link to post
Share on other sites

If your crank seal on the flywheel side is leaking, then it will suck in the water, and cause the ignition to go haywire.

see if you see any trace of oil leaking down the back side of the casing from the bottom of the crank seal. You'll have to pull your flywheel off the crank to be able to see any trace of oil leaking through the seal. THe leakage is found from behind the flywheel, which you can't see if the flywheel is on the crank.

Share this post


Link to post
Share on other sites

Do a search on jetting here. To start off, I'm sure you could improve it for free by raising the clip on the needle 1 groove and opening the air screw 1/2 turn. Beyond that it would just be a smaller pilot jet and main jet.

Share this post


Link to post
Share on other sites

Get the JD kit. I put it in my 02 and it made a world of difference in low to mid power and should remedy your fouling issues. The only thing better is the PWK carb swap.

Share this post


Link to post
Share on other sites
If your crank seal on the flywheel side is leaking, then it will suck in the water, and cause the ignition to go haywire.

see if you see any trace of oil leaking down the back side of the casing from the bottom of the crank seal. You'll have to pull your flywheel off the crank to be able to see any trace of oil leaking through the seal. THe leakage is found from behind the flywheel, which you can't see if the flywheel is on the crank.

brand new crank seals bothsides. actually all new seals everywheres and gaskets. thanks tho man.

Share this post


Link to post
Share on other sites
Sounds like a crank seal to me.

brand new crank seals jus installed a mounth ago. new air leaks on the bike. some water did get in my flywheel side because i had a gasket in wrong. but thats it. thanks

Edited by stephen99
missed word

Share this post


Link to post
Share on other sites
Do a search on jetting here. To start off, I'm sure you could improve it for free by raising the clip on the needle 1 groove and opening the air screw 1/2 turn. Beyond that it would just be a smaller pilot jet and main jet.

im already on the second clip from top i had it on the first but it feels way to lean. i have a 32.5 pilot in now i jus got a 30 to put in and im going to order a jd jet kit and replace the crap stock needle witch i beleve to be to rich.thanks man

Share this post


Link to post
Share on other sites
How old is the top end? Worn rings will mimic poor jetting, and no amount of jetting work will restore the rings.

this bike has nasty compression an will take u up an back in any gear. there is now way i have a worn top end . it also passed a compression test not long ago with flying colours. thanks tho man

Share this post


Link to post
Share on other sites

If you have a chip on your case allowing dirt in there, it will destroy your crank seal in a very short period of time. a blown crank seal will cause a rich condition which will foul plugs. JD jet kit will help your jetting in the long run but if you are fouling plugs, it is due to that blown crank seal. I would replace the crank seal and then use some sort of sealer to close the break in your case.

Share this post


Link to post
Share on other sites
im already on the second clip from top i had it on the first but it feels way to lean. i have a 32.5 pilot in now i jus got a 30 to put in and im going to order a jd jet kit and replace the crap stock needle witch i beleve to be to rich.thanks man

Good choice. The JD needles are the best you can buy. Check the float height while you are in there.

Share this post


Link to post
Share on other sites
If you have a chip on your case allowing dirt in there, it will destroy your crank seal in a very short period of time. a blown crank seal will cause a rich condition which will foul plugs. JD jet kit will help your jetting in the long run but if you are fouling plugs, it is due to that blown crank seal. I would replace the crank seal and then use some sort of sealer to close the break in your case.

100 percent not the crank seal i checked it.dry as a bone in bhind the flywheel seal looks and the case is not chiped. im leaning towards jetting the bike was never jetted since it was bought new.thanks tho

Share this post


Link to post
Share on other sites

Yea sounds like its not properly jetted. This bike is sensitive to jetting.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

×