where to start

[rooney]

i have no idea where to start on jetting my 400 idles low but the response is good riding what main and pilot jet sizes would be best it has a curtis sparks x6 exhaust 416 motor 13:1 compression je piston nology hotwire and rev box any help would be appreciated

[tri5ron]

at 13:1 compression, I sure hope you had the GT Thunder HD studs installed,...
and you will DEFINITELY need to increase your cooling capacity with a larger oil cooler and a Spal fan.

otherwise, I see a Fragmenting Grenade in your future.

[JOHNDOE83]

Get jet sizes 160 to 190 in incriments of 5, start with the 190, if it starts to sputter at wide open throttle, back off jett sizes till it stops sputtering from being to rich.

If it doesnt sputter with the 190, buy more jetts...lol.

Deffinetly take the extra precautions with that high compression.

DO NOT, use octane booster like you did before, were you able to find race gas like sunoco or e85 yet?

[rooney]

i can get ahold of e 85 easily but no race fuel yet i just dont quite understand what e 85 is going to do for me could you explain and yes it has all the extra cooling equipment

[bdubwiley]

Originally posted by rooney
i can get ahold of e 85 easily but no race fuel yet i just dont quite understand what e 85 is going to do for me could you explain and yes it has all the extra cooling equipment

e85 is 105octance IIRC, so it will def help with your 13:1 since you dont have or cant get race fuel... do a search and you will see that quite a few members are running e85 with no problems, and im sure they could probably help you a lil more than i could on the subject

[CJM]

Without some high octane grade of fuel you will get detonation, and blow the bike up.

13:1 is WAY to high to run on even super pump gas.