Mikuni 42 Questions

[tjglide]

I'm trying to get my bike dialed in and have some questions that are not clear in the Mik tuning manual.

1. Turning the mixture screw in richens or leans the mixture?

2. Does the pilot jet affect fuel mileage?

I am trying to get rid of backfiring when I let off the gas and can't seem to make any headway.

Here are the carb settings:
25 pilot
167.5 main
98 needle with clip in the middle

Motor specs:
95" 11.12 Compression
Woods TW8-G cams
42 Mik
Thunderheader
Heads fully ported with 1.9 intake valves
Dynatek ign set on 26B curve

The bike runs great except for the annoying backfiring. The bike is a dyna if it matters. Any help would be appreciated.

[baggersport]

In on the idle mix screw is richer (it's adjusting air).

Yes the pilot will affect mpg.








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[CAP]

I put a 22.5 pilot, a 96 needle in the same position, a 165 main and shorten the pump stroke in my similar build. Check you exhaust for airleaks and maybe retard timing a little bit.

[tjglide]

Originally Posted by CAP

I put a 22.5 pilot, a 96 needle in the same position, a 165 main and shorten the pump stroke in my similar build. Check you exhaust for airleaks and maybe retard timing a little bit.

Thanks for the feedback. I'm curious how many turns out is your air screw with the 22.5 pilot?