1995 Kx 250

[Monkeyboag]

MY son in law has a 95 kx 250 and it runs like crap... it pops, cuts out, backfires (that was a first for me to hear a 2stroke backfire) and fouls plugs.. It has a new rad valve,top end,and power valve.. is it the carb float?? Does anyone have any jetting specs for him to try?? Any help is appreciated...... Thanks.........

 

[Senior KX Rider]

Stock jetting for that bike was 162 main, needle 4th groove from top, pilot jet 45. If it has a RAD valve on it those specs are prolly a little rich.

 

[motomad]

A great man taught me long ago"make sure the ignition's right before you start screwing with the carb."
Having said that,also check the stuff that's new(reeds maybe? vacuum leak?)And I think Boyesen does recommend leaner jetting with the rad valve.

 

[EZ-Rider]

Originally posted by Monkeyboag
MY son in law has a 95 kx 250 and it runs like crap... it pops, cuts out, backfires ......... It has a new rad valve,top end,and power valve.....

How did it run before this work was done? If it ran okay it would be a safe bet that it has to do with one of the "new" items. What plug is in the bike and how old is it? What jets are in the bike right now? Does it run smoothly at any point in the rpm range? Have you checked the ignition? or are you positive it's fuel related?