I have a 89 lt250R with an 87 jug on it .80 over wiseco piston, clamp on K&N filter no air box, FMF pipe, scilencer, boysen dual stage reeds, im running a 35 pilot jet, the needle is 2nd clip down, and 240 main jet air screw 2 turns out and a 40:1 mixture with klotz super techiplate oil, the thing blows smoke all the time, what should i do ??????????

 

Inspect your sparkplug. At nominal temp it should be a coffee with creame color. Ride the thing and see where it is the most rich i/e blowing out smoke. Ajust your jetting accordingly so that the richness stays constant throughout the rev range. Then i would recomend going down 2 jet sizes on your pilot and main jet, then see how it runs.

 

Did you ever get your jetting fixed? Seems like 240 main jet is small with the mods you have.

 

still having probs, i took off the K&N clamp on and put on the air box, and did a total rebuild on the top end, new sleve and it is back to stock, and im runnin a pro lite piston in my 87 jug and it seems to run fine with it, but im still lean when starting and idle, i have a 40 tm 8 hole pilot jet in it and it still revs at idle and blows smoke, i cant seems to get any thing out of it, wont going down on my pilot jet make it leaner, making it rev more ? the only thing i can thing off it is getting air, but from where ?

 

My 86 smokes at idle, no big deal. Just make sure that your not running too rich.