rutlandtrails
Member
- Dec 19, 2005
- 5
- 0
rutlandtrails said:ok i have a 2001 KX85 and it will run perfect for about 2 days but after that second day when you go out in the morning on the third day it will start and then die........so i take out the plug and its wet with oil.......the carb is tuning is stock and im mixing the gas at 32:1.........its not leaking bottom end oil or anything and my question is would going to 40:1 help my problem or not help and will it hurt my motor? sorry about the book any help would be greatly appreciated.
thanks rutland
mattb348 said:KX's seem to always seem to have a pilot jet that is to lean. I would try bumping down the pilot (also know as slow jet) by a couple sizes (maybe even more). I actually bumped down my 250 by 4 sizes on the pilot jet. I wouldn't jet yours down that far though.
i_955 said:Mattb348 must have meant RICH, not LEAN.
I agree with the rest as I had to reduce (lean) my pilot size by two on my KX100, my needle by 1 and enlarge my main by 2.
I still have to increase my main by one or more now that the temps have fallen.
nikki said:Are you running the stock R6252K-105 plug? If so, try a BR9ES (one step hotter than the stock 10) or BR8ES if you still foul the 9.
mattb348 said:Isn't going down 2 heat ranges a little hard on your engine though? I think it would be better to just rejet.
rm_racer said:Im pretty sure the plug heat range is just the tempature the plug clears at? Im not sure tho. If that is the way it works I cant see any potential damage to the engine. This is just a quick fix tho, as rejetting would be the proper fix.
DLHamblin said:Not necessarily. Depends on the bike (stock/modified), jetting, and rider ability.
While its correct to say you shouldn't use spark plug heat range to try and fix bad jetting; its also equally wrong to try and fix all spark plug issues with jetting as well. They kind of go hand in hand.
An example is my son's YZ-85 (2006). Stock they come with a BR10EG which lasts about 30 minutes even if jetted correctly (unless you are on a MX track where the throttle is never closed). Be on a slower track or trail riding and it fouls in 30 minutes (with proper jetting). Lean it to where it won't and the bike is too lean and runs like crap. Put a BR9EG in and it will run for weeks (for just trail riding we use a BR8EG). Bike runs well and neither plug looks like its running too hot.
Bottom line is don't randomly drop 2 ranges without doing some follow-up checking; but if the jetting and top end condition are good; don't be afraid to go one range at a time hotter plug. The bike will let you know its too hot by pre-ignition (which is what would burn the piston, not the plug itself).
I know this post is old but wanted to re-hash anyway...i_955 said:Mattb348 must have meant RICH, not LEAN.
I agree with the rest as I had to reduce (lean) my pilot size by two on my KX100, my needle by 1 and enlarge my main by 2.
I still have to increase my main by one or more now that the temps have fallen.
mattb348 said:Isn't going down 2 heat ranges a little hard on your engine though? I think it would be better to just rejet.
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