Re: Fuel in intake
 

List 4668

Re: Fuel in intake
 

is the base plate or carb body warped???

Re: Fuel in intake
 

might be on to something, base of carb body is warped .011", top of base plate is .002"


I think I'll find some socket head screws to replace the Phillips head ones.

Re: Fuel in intake
 

Well I made some progress. The screws are #12, so I didn't have any of those, so I tightened up the base plate best I could and ran it. The last few times I've run this engine,the vacuum floats from 8-12 in. with the rpm tracking the the vacuum, acted the same this time. Took off the carb and there was still fuel in the intake, maybe a little less. I took the carb base plate off and the base, body, and gasket were pretty much dry. Previously they were soaking wet. Far from a slam dunk, but it's worth pursuing. I think I will try to re-surface the body and get a new gasket.

Re: Fuel in intake
 

Ok, I have finally found the real issue here. I did end up re-surfacing the bottom of the body and that is sealed up well. My original thought was to take out the power valve, I never tried that. So after looking at the baseplate, a lightbulb flickered on. First picture shows how I originally had it put together, second one is the fix.

Re: Fuel in intake
 

So changing from a 4 hole to a open plenum manifold gasket solved your issue?

Re: Fuel in intake
 

It made a huge difference in the idle. from what I see, the first gasket blocked the source of manifold vacuum that feeds the PV. I think the PV was opening during idle. At least that is my new theory. Spark plugs are now dry as well.

Re: Fuel in intake
 

Make sure you have some sort of 4 hole gasket or something else, like a 4 hole thin spacer, to keep a base plate to bowl screw from getting loose and backing out and falling into the engine through the intake! Holleys do that.Could save you an engine.

Re: Fuel in intake
 

Thanks Greg. Good point. My theory #2 didn't pan out. Although I've seen fuel stains where there shouldn't be any, so trying a few things. Pretty annoyed with this carb as it's fresh from one of the name gurus, but I guess it's a good training experience for me.

Re: Fuel in intake
 

I think I've fixed this issue. I had thought the PV was opening because of the base gaskets. Well I found that fuel was collecting in the vacuum space in the body behind the PV, and was being pulled in thru the vacuum port thru the baseplate. Gaskets were leaking bad on both ends. I re-surfaced both ends of the body where the fuel bowls go. Amazing how bad a shape they were in once I started working on them. I will never build a carb without doing this. The vacuum space is dry on both ends now and spark plugs are also dry. Still a little fuel in the intake, not going to worry any more about that. I'll see how it runs. I won't mention who built this carb, but he was recommended in a thread I started here. Stevie Wonder could have diagnosed this problem. And thanks to all that helped. On to the next problem......