I have an 86 250R w/ an FMF Gold series Fatty pipe/sil., K&N filter (just cleaned and lubbed) and V-force Reed valve. The thing should have some power over stock? wrong!

I run a stock carb w/ 155 main, #6 needle in the 3rd clip position and I believe it has the stock pilot (48 but I'm not sure 'cause I've never checked and I run 32:1 w/ Klotz technoplate.

Now, she lacks lowend. Not only that but sounds unclean and has a sputter ALL THOUGHOUT LOWEND IN FIRST GEAR. But it sounds fine once I shift into second. Now THAT"S weird and makes no sense to me. It hits kinda hard when it finally does come on and seems to rev out ok but will actually flatten out and lose a bit of speed when shifting from 5th to 6th at full throttle. The intake where the reed valve is is missing a bolt but that should be a problem should it?? afterall it is still sealed by the other bolts and a gasket.

The main problem is the holeshot. My brother's stock 86 R beats out consistently beats it out off the mark by 2-3 quad lengths and then as I hit the midrange it doesn't really catch it just stops the stock are from pulling away.

What could be wrong??

 

You should do a plug check at 1/2 throttle to determine proper needle height, and a plug check at full throttle to determine the proper main jet.

Did you re-jet after putting on the aftermarket parts?
You should have had to go up on the main jet AND drop the clip a position to start out with.

Yes, you should replace the missing bolt. It can cause you to run lean!