4 mill jetting need help.

[spdbyspanklyn]

Hey guys. I am new to the HQ, great site. Anyway, I need help with jetting my bike. The motor is a 4 mill 115 long rod hot rods crank t-rex cylinders bore at 68.5 mm dune/drag port, CPI small bore inframes, 35mm keihen pwk 168 mains and 55 pilots. cel needle third clip position + 4 timimng. mixing ratio is 32:1 110 octane fuel. Last year I had a problem with the motor dying off in the top end.

[sleeper06]

Have you done a plug chop at all,I would think you would be lean on the main,when you say dying on top does it shut down or spudder

[spdbyspanklyn]

Have you done a plug chop at all,I would think you would be lean on the main,when you say dying on top does it shut down or spudder

Whats a plug chop? It will not rev out after 2nd gear.

[Larry's Shee]

Possibly fuel delivery problem? Bad petcock or float level or cap vent.

Search "plug chop", to much to type.

Edited June 15, 2011 by Larry's Shee

[sleeper06]

I know each cylinder pulls fuel diffrent that t-rex might actually need less fuel because it pulls it better,i would check with someone who has a similar set up,other than that try richening it up try a 180 main and see if it helps if not go down,if no jetting helps check electronics

[spdbyspanklyn]

I know each cylinder pulls fuel diffrent that t-rex might actually need less fuel because it pulls it better,i would check with someone who has a similar set up,other than that try richening it up try a 180 main and see if it helps if not go down,if no jetting helps check electronics

will do. Thanks a lot guys.