Muscle jet tuning game plan

thor_eyerdhal · Sep 15, 2014

I tried the FP needles, NO WAY to get a good AFR at WOT with them, they give a very rich ratio.
FP make them to work with their Vmax kit wich was designed to work without air restrictors..
So carbs need big jets and thin needles.

Traumahawk · Sep 15, 2014

Edited for content

thor_eyerdhal · Sep 16, 2014

FP think another way (i don't tell this is the better one) : more air give better emulsion.
So their kit don't provide air restrictors, so you have to use very big jets and thin needles to reach correct AFR

In the Vmax carb, the needle diameter is involved event at WOT.
Check your AFR at WOT with same jets and different needles ...

Thats because the needle never goes out of the emulsion tube, it act as a restrictor of the main circuit.

bikedave99 · Sep 16, 2014

thor_eyerdhal said:
FP think another way (i don't tell this is the better one) : more air give better emulsion.
So their kit don't provide air restrictors, so you have to use very big jets and thin needles to reach correct AFR

In the Vmax carb, the needle diameter is involved event at WOT.
Check your AFR at WOT with same jets and different needles ...
Thats because the needle never goes out of the emulsion tube, it act as a restrictor of the main circuit.

Don't mean to thread jack, but was reading your sig Thor, and I think we need to see some pics of your bike!

Traumahawk · Sep 16, 2014

Edited for content

one2dmax · Sep 16, 2014

The needles have NO effect on if you need the air correctors. That is determined simply by the volume/velocity of the incoming air. So, if you have removed enough restriction from the intake (pod or our filter) then you have to use the air correctors. The only other way around this would be to install HUGE mains which then makes tuning all the rpm ranges virtually impossible.

The FP kit is designed for the stock airbox with or without K&N filter.