Motor help

[440ex kid]

I just got my motor running. It has a 426 11:1 piston and an HMF slip on. I am running 93 octane pump gas. Well there seems to be alot of carbon coming out of the pipe. And today, every time I would let of the gas it would sputter (not backfire).

Now I think the problem might be not enough octane. But would that cause it or do I have other problems? Should I cut 93 with race gas? Any help would be great.


By the way I am running a 165 main jet with no lid.

[hondarider2006]

Try mixing like 60/40 with race gas, and see if it solves your problem:)

[440ex kid]

That was my plan. thanks.

[K_Fulk]

Your jetting is to rich. try a 152 -155 main and a 40 pilot, and fine tune it with the fuel screw on the bottom of the carb.

[440ex kid]

I jetting to rich?!?! HMF requires a 175 for a slip on. Im only running a 165 with no airbox lid. Ill give it a try.

[K_Fulk]

I ran a 155 with a 440 open airbox and x-6 pipe. And I was still a little rich then.