Stumped, need some suggestions.

[smudvapor]

Okay, here is the story. At the last race (last month) I rolled my machine over. Before that it ran fine. When I went out for the next race I got about half a lap in and the engine started acting like it had vapor lock then it died. It starts up no problem and if I rev it up to high rpm’s it runs great but from idle if I hit the gas it dies. The only thing I can think of is something happened when I rolled over. I pulled the bowl off and checked the floats and that all looked good. I have to believe it is a carb issue but I don’t know what. Any suggestions on what it could be?

JLO 440 with Cuyuna 6 bolt hemi heads
Mikuni VM36 Carb
Point’s ignition

[hydromike]

I would also check the fuel line in the tank, and any fuel filter you're running. Chances may be that you dislodged a chunk of crud in the tank and sucked it up into the intake tube. Are you running the steel or poly tank? It never hurts to rip the carb apart and inspect the pilot/main jets for debris. It doesn't take much at all to block them. Take them out completely and do a good visual inspection versus just blowing air or running a piece of wire through them. Let us know what you find, if anything. Everybody can benefit from simple fixes. I completely forgot I had a fuel filter hidden away in the body of the 503R, which had become plugged and caused my quick exit from the mod race this rear. Sorta silly after rebuilding the entire machine, but that's life...

[smudvapor]

Pulled the carb apart and it looked great inside. Cleaned everything anyway. Checking the fuel lines and filter after lunch.

[riotwarrior]

Does fuel tank have a clogged vent line?

[smudvapor]

I figured it out I think. The air screw on the carb somehow got turned all the way in. It seems to be running fine now. I will fine tune it on Saturday at practice.