hello klxers. just bought my first klx 250, 94 with the 300 head, tm33 pumper carb and airbox lid taken off, stock exhaust butt plate removed. i cannot get it running good. i have changed all the fluids, cleaned the carb and replaced the plug. my fuel screw is only about 1/2 turn out but my plug still shows its running rich(black plug?). it has a little popping on decel and i can only get it started with starting fluid however the throttle will keep it running(idile jet?). im lost, ive searched, read and tried so i figured id post my first thread and see if im missed something. i hope its not the intake valves. would the tm33 pumper carb on a 300 stock setup cause really rich conditions?
thanks brett

 

Hey Brett, welcome to the forums. If it were me I would make sure the valves were set right then work out from there. Fuel screw 1/2 out? hmmm my wife's 225 is 3 turns out, 1/2 doesn't sound right.

 

thanks man. ive read that 2 truns out is where you should start and thats what i did, but it ran better the more 1/4 turns i made in. now my right foot has no arch just a huge bruise from kicking this thing all day

 

Wait a minute, when you say you cleaned the carb what does that mean exactly? Did you pull the jets one at a time to make sure they are not plugged? I don't think that valves could be the problem if tinkering with the carb changes the way it runs. If it were the valves, it would be a constant problem no matter what you did to the carb. Take another look. Also make sure the rubber boot material doesn't have a crack or hole, that can be another problem area on older bikes.

 

cleaned with chemtool b-12 and sprayed through all jets. i thought i was pretty meticulous but i dunno. im just confused why my fuel screw is only about 1/2 turn out and it seems to still be rich. is there another adjustment other than the fuel screw that im missing?

 

Fuel screw isnt going to change what you see on the plug, unless it fell out. Check the valves, those ealy 250s. Had soft valves

 

how is it jetted?

 

You'll need to post your mods, elevation, & manf & size of jets. With that info, we could lend more advice. It probably would be a good idea to at least check your valves, if your pulling the carb anyway, it is only another 30 min to check and then you know. Set them up loose side of tolerances.

If your fuel screw is in and it runs better that way, your jets are probably to big.

 

ok i pulled the jets out and the previous ower has a 20 pilot jet and a 140 main. bike has a 300 barrel, tm33 pumper and airbox lid cut off. other than that it is stock as far as i can tell. my elevation is 500ft above sea level. im going to check my valves this weekend

 

Good idea to check the valves. If they're OK, make sure the pilot jet and the area it's seated in is cleaner than very clean. The 140 main could be the reason you're running rich.
When it runs does it smoke? What color?
Not sure if your bike requires the special starting technique that the older 300s use. There was a problem with the ACR and it's relation to the exhaust cams. They are a beast to start if you don't do the dance.
Anyways, with my 300 I need to engage the kick starter until I find TDC, then go past it about a quarter to half kick. Then allow the lever to return to the top. Then give it a good kick.
Foot was black and blue until I learned the dance step. Now it usually starts 1st kick.
Good luck and let us know how you're doing.
Rob