Carb troubleshooting

[wtm442]

Originally Posted by MrMagoo

The pressure seems to be staying steady at 6.5. The engine is just up to normal operating temperature when it honks out. Although I think, in general, my fuel temperature issues need to be addressed, I am now leaning towards jetting as the main problem. Carb tuned for max power, I have a restricted exhaust, hence too much jet for the air I can pump.

Overly rich jetting is NOT going to make the engine quit in 5 minutes. Put in the carb spacer before doing any carb changes.

Then adjust your float levels. Check float levels again after a 5 minute drive where you open the secondaries a couple of times. I know that will be a tough job.

Now check the condition of the plugs. It is probably time to change them. Now set the idle screws and take it for a ride. If it still smells rich, then change the jets.

When I first bought my Cobra (used), it smelled very rich. I adjusted the idle screws and the smell from the exhaust was eliminated. Then I had one dyno pull, just to see what the mixture was like. It was LEAN. I had to go up in jet sizes - 3 steps on both the primaries and secondaries. What a difference!

The 7 PSI at idle is OK. If you bought a Holley Fuel Pressure regulator, the factory setting is 7 PSI. Of course, you should also have at least 4 PSI when running flat out ... thru the 1/4 mile traps, for example.