I installed the two rebuilt 400 CFM Carter AFB's & I'm having what I think are percolation/evaporation issues. After the inital start up, idling & tuning, I noticed the accelerator pump squirters had very little fuel flow when the motor was reved up. So I shut it down, pulled the carbs & checked all the passages & orffices, all was fine. Float levels were good, fuel pressure was 7 lbs. Went to crank it the next morning & had to use starter fluid, drove it down the street & it ran great. Next day same hard starting, so I checked the bowls & had 1/2" of fuel in the bottom. 90 deg weather & not enough insulated gaskets is my guess. Any ideas/suggestions are appreciated. Thanks, acr
I've got a 90-100 micron in the line, near the tank, maybe has 500 mi on it, new gas tank was installed at the same time. And a new Jegs 30 micron just before the carbs. Pump is NOS Carter M-6900, it's been on the car for about 500 mi. worked just fine. Lines are Russell braided nylon "Pro- Classic" lines.
Make sure the pump hasn't got a ruptured diaphram *(fuel in the oil)- from there, you might build an aluminum plate to shield the intake heat ( about 3" bigger than the carbs all around and bolt between insulators and carbs. This is one of the resons I like electric pumps- flip it on for a few seconds before starting and you are full. You might try spinning it over a few revolutions with no pedal to fill the carbs, pump it 3 or 4 times and fire....
I'm happy to report I got the car running tonight ;D, however at the insistence of a friend who had the same problem, I removed the fuel filter & ran the line straight to the carb. He thinks the horizantal filter with a down ward tilt, like I have, can cause the carbs to drain & possibly also cause air pockets. But he agreed that I may still need heat absorbing spacers/gaskets. I didn't do any tuning, I just wanted to get it running for now. I was able to re-start the car after a warm up & short drive, then sitting a few minutes, but the test will be if it cranks in the morning. I'll post the outcome tomorrow. acr
Well the car wouldn't start this AM so I I'm back to percolation or maybe a sticking needle/seat problem. How much fuel should be in the bowl after the car sits overnight & how can I determine which it might be?
Good news on my 2x4 project, I rotated the filter & line to a horizontal position instead of the downward angle it had. The fuel level in the bowls is now stable & where it should be. Following Damon's advice, I pump the accelerator pedal 10-12 times, (no chokes) turn the key & it fires up. I still think I'll need some heat resistant/absorbing spacers between the intake & carbs & found an article on the thermal conductivity of various types of spacers I'll post separately.