I have owned 6 big twins and modified several carbs with great results. Just purchased '06 Sporty that spits through carb. Installed S/E mufflers and free flow intake. After several attempts at slow and main jet changes, drilled and undrilled slide, early and current year jet needles, stock and light slide springs, carb still spits at idle during low end acceleration. Took Sporty to
local high performance shop. They could not fix after several attempts. To Sporty well know H-D engine builder with dyno. They dyno'd carb, but said the '06 Sporty ignition module has retarded timing at idle rpms. They say fix is after market adjustable timing module. Carb still spits. Any ideas or input regarding carb spit or aftermarket module. Thanks in advance, Santino

 

What jet sizes are currently being used?
Scott

 

Could it be do to pressure from a valve not seating correctly?

 

IMO it s the idle air circuit that needs to be adjusted. 2 1/2 turns out is good starting point. dsv

 

Usually a .45 jet is a good starting place. Next would be a richer needle.

What is current needle number?

Also check for intake leaks at the head to manifold connection. If it has been sitting for a while the may be dry rotted.