Shearer inframe jetting

[Long Rod Todd]

I just installed a 4mm stroker, lightened flywheel (Boonman), Prodesign adjustable advance plate, v-force 2 reeds,boss racing intake manifold,cool head, Passion 12 port stroker porting, Shearer inframe pipes, 35mm PWK's with Dual K+N filters.

 

The carbs are currently jetted with 52 pilots, DEK needles on the 5th clip position from the top, I recently moved up to 175 mains from the reccomended 160's (starting point).

 

I have never ridden with these pipes before and seem to have a major bog at full throttle at lower rpm. The bog was worse when I had the 160 mains in. I am finally through with the break in period and was wondering if the main jets seemed a bit big considering most people seem to run 145-160 range. I didn't have much color on the plugs when using the 160's. This thing pulls like a mother on the top end and revs to the moon. Midrange throttle between 1/4-3/4 is all good. I'm at sea level with the temp between 40-60 degrees right now. So I need a sugestion on what to do with the main jets and also how much to advance my adjustable timing plate. Thanks

[wesw]

i ran 60 pilots, 5th clip on dek, 145 mains, +4 timing should be good

 

 

you might start at a 150 mains and go from there.

 

best of luck

[BansheeGuy_IV]

Hiya,

 

I Have almost the exact same setup... I'm at sea level. 12 port, Trinity heads with 17cc domes, V-Force 3, Modquad intake, 35mm PWK A/S carbs, Timing +5, and shearer pipes.

 

Here's what I am running. 165 mains and CEL needles on the middle clip position. 45 pilots. Runs like a dream.

 

I have about 30 sets of keihin needles... Every combination you can image... every main jet from 140 up to 190+. I experimented with each needle, until I found the one that worked the best.

 

Basically, what I found was that any needle ending in "L" would make my low-end nice and crisp. The CGL needle ran great, but there was a tiny bit of missing/surging in the 1/2 to 3/4 range. When I moved to a richer taper, DGL, then the midrange was rich and flat. So I went to CEL and the rest is history.

I experimented with alot of other needles with no success... DEK, DGM, DGN, EGL, EGM, EGK, CGM, CEK, CGK... The list goes on...

 

 

Good Luck,

 

BG

 

 

 

 

BG

[Long Rod Todd]

Thanks for the suggestions. I'll pick up some more main jets and start lower. I think the problem with the plug color was due to running a little lean on the needle when breaking it in and not going full throttle that much (started with the needles in the 3rd clip from the top when first assembled). I guess I'm being a little to worried about running it lean after dumping some $$$ in to the motor.