CorvetteMikeB

Could it be Vapor Lock???

prestige6

I'm going to put 1/4 inch plates between the carbs and manifold.

CorvetteMikeB

That is suppose to lower the fuel temperature in the carburetor reservoir I read somewhere.

prestige6

How can I tell if a power valve is bad??

prestige6

I was talking with Phil at custom carbs . He told me to put the spacers in the carbs which I did. He also said it could be the fuel pump. When running at highway speeds the carb is working fine. As soon as you come to an idle the pump could be producing more than 7 lbs. causing it to load up. That's why I want to install a fuel pump gauge and regulator.

Frankie the Fink

You can measure the fuel pressure basically with a $13 vacuum gauge/fuel pump pressure tester and have your answer in 8-10 minutes -- no reason for a permanent gauge and re-plumbing your fuel lines... You prob have more pressure at cruise with the pump diaphragm cycling faster....

There is a ton of tri-power info at the bottom of this web page and it might be interesting to read through it:

http://www.thecarburetorshop.com/Troubleshooting.htm

tbarb

There is such little fuel consumption at idle speed that is where a mechanical fuel pump will make it's highest pressure. Every turn of the camshaft resets the diaphragm high against the spring where max pressure would be and the diaphragm moves very little because of the low fuel demand.

The secondary carburetors have idle circuits and the gaskets where the metering plates screw to the main body can leak causing a rich condition if that's what you are questioning.