mainjet for my setup ?

[NitroObsidian]

Hello , I will me soon build a 421cc engine.

 

my setup :

 

-68mm Kit Driveline Assassin's HP

-Dome 21cc

-Keihin 38mm pwk

-Shearer out of frame with silencer

-crank +4mm

-Tassinari V-Force 4

 

 

 

Would you have any idea of mainjet ,that i must take ?

 

I see a lot of setup 421cc with 35mm carbs and mainjet about 140~170. but with 38mm carbs ? i did not find.

 

last question : i have a timing plate (at the moment +4° @stock cylinder). But with this setup ,How many can I put ? my use is only onroad.

 

Thank you for your help

Edited June 20, 2016 by NitroObsidian

[guns4children]

Timing would all have to do with what kinda octane of gas you plan on running. As far as the jets go i don't see that bug of a difference between 35 to 38 I can't imagine the jetting would be off by much.

[sleeper06]

What kind of road , like daily driving or drag racing on asphault,. 21cc domes are gonna leave u needing over 100 octane fuel timings depends on intended use jetting will vary with compression/timing/fuel so know what you want to run..what pipes do you have?