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Author Topic:   KP - Carb Problem
posted August 09, 2003 09:46 AM
This past weekend our motor began to run rough, not missing but kind of loaded up. When investigating we found the carb spacer and the top of the intake covered with fuel. Checked to make sure everyting was tight and went back out for the heat race. The driver said the motor was much better but there was still fuel all over the spacer and intake. Did the same thing in the feature.
The fuel appears to be coming from around the primary throttle shaft, but cannot tell for sure. We checked the float height fuel press. etc. and can see no problems, we are stumped.
Any ideas what this could be, is it someting in the carb. It doesnt do it in the pits if we rev it up only on the track.
This is a 750 alcohol carb on a 406 with a victor JR. intake and a 2 inch carb spacer.
Please help


posted August 09, 2003 12:17 PM
If it's not a case of pullover from a mis-adjusted primary idle circuit, or from too high a float level, a stuck needle/seat, etc, then the next thing I'd suggest looking into would be the power valve on the primary side (assuming like you said, it's only coming from the primary side).
The power valve could be blown.
Another clue that it's the power valve would be if there is fuel in the cavity in the main body behind the power valve when you remove the metering block. There shouldn't be any in there.
And while you're inside the carb, it wouldn't hurt to insure that your air bleeds are not blocked or restricted as well. Just shoot carb cleaner thru them in both directions with the metering blocks off.

Hope that helps, and let me know.


posted August 09, 2003 12:46 PM
Thanks Kp

I plan on taking the carb apart and checking all that you suggested. Ill let you know what I find.


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