more jetting thoughts from someone less intelligent.

[dank]

ok, i love the way m bike runs down low, but once i get say 1/2 throttle, its like the rpms stop and hover. i dont notice this so much riding, other than it just seems to run flat, at which point i shift, but that happens right around 1/2 throttle. its gets flat and kindof sputtery, i dont know exactly how to describe it. so im wondering where to start. i have a 40 or 42 pilot, i cannot remember which right off hand, but the way i understand it the pilot only really comes into play at the lower end of the rpms, i also have a 178 main jet, and i have no clue what needle i have. i tried to take out the retaining screw on top of it, but i could not find the correct size (i think its supposed to be a 6, but i think a previous owner tried to use SAE tools and stripped it out. the size is somewhere between 5.5 and 6mm, but neither work.) so im wondering if i should take a vice grip to the screw and try moving the needle and replacing the screw, or if i should try a different main? i dont know if its running to rich or too lean on top, but i think it would be safer to move it richer first and see what happens before i go leaner. any suggestions would be great!

 

[wence]

I would check and clean out carb with air and petrol.
Also take a look at the muffler and check the packing.
Just a few ideas ..... I had a few dramas with both with a similar problem whe n I first got the bike.
Cheers Mark

 

[dank]

just cleaned the carb, and it has new packing.

 

[Brian]

Sounds like the needle to me, but what do I know. If your plug doesn't look to lean (whiteish), I'd try moving the clip from one extreme to the other and see if that changes what you feel. Also find out what needle you have. Someone may be able to give you some advice...