High speed sputter?

[moochdog]

Having some issues w/ my 1997 Warrior. Sometimes when running at full throttle, it has a light sputter. Cant really feel it, can only hear it. I am wondering if this is jetting related or possibly timing. It has a full yosh. exhaust, uni air filter, holes cut in air box. I just rebuilt the carb and rejetted. It has a 45 pilot, 145 main, clip in middle slot on the needle. I had initially installed a 150 main and it seemed to sputter quite a bit more, so I backed it off to a 145. Could the sputter be from running rich? After doing some research on jetting w/ the exhaust and holes in air box, it seems like most people run 150 mains. I am nervous to back the main off any more than 145 due to possibly running too lean. I live in Michigan (not high elevation) and have been riding in 20-30 degree weather. Is this a jetting issue or could it be timing or something else? Any input would be appreciated.

 

[Venom]

i run a 155 main, no airbox lid and uni foam filter, needle on stock position, and 45 pilot fmf pipe, no sputter at all , altough i m running a bit rich. My carb had a 142.5 main i think witha 150 you will do fine ,145 sound a little lean...
I think you will only have timing issues if you have your timing chain very streched.

 

[Gen1Pat]

You need to do a plug chop and see how well the air/fuel is burning.

 

[lbjamm]

You need to do a plug chop and see how well the air/fuel is burning.

Agreed