Jetting Help

[treblvmaniaco]

I’m having trouble with dialing in the bike’s power & was wondering if anyone had any suggestions ?

Bike has Shearer Pipes with a Full Port Job & Billet intake with K&N filters, stock crank.

Stock Carbs 

350 Main

30 Pilot

Air Screw 1 1/2 out

Idle Screw 2 1/2 turns from contact 

Elevation 1000 Ft

Temps 70-85 F

 

Thanks for the help

 

[AKheathen]

"full port job"  tells nothing.   porting should be done on the builder level.   a builder should be able to tell you which fat jets to start with, so you can tune it from there, usually within 1-2 sizes from perfect.  

...that being said:

               holy shit that is fat as hell on the getting.  i bet it sputters down like crazy.   a master jet kit is ideal, but if you are buying individual, get some 27.5, 270, 290, 310, and 320.    honestly, i want to say you will find 280 if the sweet spot for your setup, but i have no idea about the porting, and 290 would work fine, while being safer.   get it hot, then do some hard pulls through all the gears, barring any huge hesitations and evaluate.   2 sizes rich, and it will start to sputter at wot.  2 sizes too lean and you'll get a big wot hesitation.  one size either way, and aslo in lower gears, its not so obvious.  you want to find the 2 extremes and get between them. 

things that will make a big difference:

humidity.   i say this first because its more overlooked, and less noticed till your bike acts up.   more moisture means less air and same fuel.  it wants to lean to burn right.

temperature.   more heat means the fuel will act differently.  all fuel is multigrade.   basically, the lighter fuel will use up the oxygen fast and leve unburned "diesel to go out the exhaust and load up the plug.   less fuel for more heat, more fuel for colder air.

restriction:  imagine a shop vac hose with a jet in it.  put your hand on it and it will pul more from the jet.  remove your hand and it will pull less.   air filter restriction from being dirty, air filter housing, etc.  all effects fuel draw.   always start with the main jets wot, then adjust the needle for mid, then pilot and airscrew for mixture and off idle acelleration.