Can' tell for sure from here,but the 158 is probably too much,do you have other jets?like 150,152,155?might consider buying a whole kit.always check plug after each change.I would start at 155.You already know the 158 causes a foul.

 

Allright tomorow I wil go buy as many spark plugs and jets as I can for $30 and I should be set for a day or 2. PS jason 300ex "what is the proper way to turn a 2 stroke" lol

 

buy the next 2 sizes down. 155 and 152. 5 bucks apiece and a case of plugs for 20 dollars.

 

I noticed that you are running a '9' heatrange plug. If you are doing alot of woods riding, I would switch to an '8' heatrange, as it is less prone to fouling in partial throttle situations.

 

I agree with Dill, change to an 8 series plug and you will have way better luck. I used 9's when I first got my R and fouled them out a lot, now that I switched to an 8, the only time I foul is when there is some sort of problem.

 

2-sTROKES DON'T FOUL PLUGS ANY MORE THEN 4 STROKES. iF YOURS DOES IT'S NOT SETUP RIGHT. ALL THE PEOPLE WHO HAVE HAD PROBLEMS WITH 2 STROKES DON'T UNDERSTAND ENGINES AND WOULD BE HAVING THE SAME PROBLEMS IF THEY HAD A 4 STROKE.

1. First always use the same oil -gas combo---Don't change brands of oil all the time, (the jetting is affected)

2. Use a quality sythetic oil Maxima 927 Mix at 32/1

3. Use BR9EV Plugs Much better plug then the crap es plugs.

4. Do a plug check. Warm bike, Run through the gears WOT till 4th gear-shut it off, Pull in the clutch and let go of the throttle. Glid to a stop. Look for a tan color, if not jet one down EXAMPLE 158 down to a 155 Run the bike for a bit and repeat.

5. If you are still having problems your burning trans fluid.

 

Well I was thinkin the same thing as you Dill and rhino99 so as soon as I got back from school I went and bought a BR8ES and a BR8EG, then I lowerd the neadle clip one spot and now is runs awesome. But I have one more question! I run it without the airbox lid now and it seems to have more bottom end and less top end speed, am I just getting useto the R or am I really missing some top RPMS?

 

Your needle may be part of your top end loss. It may have you running too lean on top. Its mainly a half throttle adjustment, but still has a little effect on top I think. Did you check your plug after you did your changes? If it was black before like you said then you should go ahead and check again and see what its like. It souldnt be black, should look something like paper grocery bags color.

 

Well I just yanked out the plug and it is black not wet like before just alittle black. It is not smokeing alot anymore and seems to be running cleaner. I dont want to F*** it up !! but I want it to be running 100% I may go riding this weekend and I would like it to be running good. THANKS !! Zeebo

 

I run a BR8ES in my R