hi. i have a 1989 it runs oretty good but it fouls out plugs real fast, about 2 every time i go riding and this is getting expensive and annoying, when im not on the gas i have the clutch pulled in and am revving it( goin down hills mostly) i am not new to 2 strokes and know about them having to be on the gas alot, but i cant figure this one out) i have a new air cleaner, and a new top end just put in what can be the problem>? jetting maybe? any help is appreciated, thanx -jason

 

i forgot to add that its a kx125, thanx

 

your either running rich or your choke isnt fully dissengaged (spelling?). How about some more info such as does it have a pipe or has it always fouled plugs? try going down a jet size though. I have to get on mine every so often to clean it out. I have a cr250 though. 2 strokes dont make very good "trail" bikes.

 

i got an fmf pipe, and fmf fatty silencer on it, i dont ride trails i ride at this track in canton called outlaw extreme, there a step down jump there with a lot of hill left to go down after you land. i just started doin this. not right away after the new top end.

 

Try mixing the fuel at 40:1 instead of the recomended amount. Your doin it right by holding the clutch all the time. Never let the clutch out unless the motor is already in powerband, and if it starts to fall drop out of powerband feather the clutch.

Keep the gas pinned all the time, use the transmission to control your speed.

 

before i had the top end re done, there was no power band init. im serious there was no kick or jolt or anything to the top end when there should of been. there is one now kinda, not a lot but u can tell that its tryin to work. is there a way to make more of a power band to the engine? can you replace a power band or what is the power band? im new to workin on my engines like this, but know some stuff about bikes, but nothing about powerbands. thanx-jason

 

There is no need to keep the gas "pinned" all the time. Only do that if you enjoy rebuilding your engine. The powerband is were the engine makes the most power (rpm's) it is not a part in the engine. I would suggest stepping down a jet size or adjusting your needle. Check your plug after 30 minutes of run time. I use one bottle of golden spectro to 5 gallons of at least 91 octane gas. I have a cr250 though but that ratio should work fine for your bike.

 

ok thanx for all the help., im gonna try a lower jet size, and new gas ratio, tomorow, thanx for al the help-jason

 

Don't forget to gap your plugs

 

what do you mean gap my plug? check the gap etting with the owners manual then set it with the setting tool?

 

exactly. One more thing make sure your air filter is clean that can cause plugs to foul also. Let us know how everything turns out

 

How much does your bike smoke and what color is the smoke? A bike that is jetted well shouldn't hardly smoke at all.

 

the bike doesnt smoke, just a little bit when it fisrt starts, its a gray color but about 5 seconds later it quits smokin