Mercury Cougar Owners banner

1 - 15 of 15 Posts

·
Registered
Joined
·
304 Posts
Discussion Starter #1
My Holley 4160 600 cfm carb started leaking out one of the dime sized plugs on the fuel bowl. Called holley and got a replacement bowl. And rebuild kit. I did not rebuild the carb Just used Bowl gaskets, power valve, needle and seats, accel. pump. Carb was perfect before leak. Problem now is it runs way to rich, black smoke out tail pipe. Rechecked float level and perfect. Adjusting idle mixture screw does nothing. What am i missing here? These bowls are so easy to replace i didn't even take the carb off the intake manifold. I did both primary and secondary bowls.
 

·
Registered
Joined
·
434 Posts
Define what you mean when you say adjusting idle mixture screws changes nothing. Was the replacement power valve the same? Are the neddle and seat valves the same?
 

·
Registered
Joined
·
304 Posts
Discussion Starter #3
Yes same needle and seat same #65 power valve. It runs so rich it won't idle. Funny thing is if you look down the carb i don't see anything flooding over like a stuck needle. When car is running. Float level is good. It's like it is sucking gas from somewhere internal.
 

·
Premium Member
Joined
·
2,142 Posts
What I have seen is that when the metering block gasket is leaking the idle mixture screws don't do anything...which is your case.
Hopefully you tightened the power valve against the metering block.

Next, go around and snug the fuel bowl bolts in an "X" pattern until they are as tight as "possible" -- don't over do it though! This is a constant problem with the Holley.

Try it and write back
 

·
Registered
Joined
·
304 Posts
Discussion Starter #5
What do you think? My new bowl has a little red rubber one way check valve and my old bowl has a steel ball that the accel. pump works off of. I put my old bowl on and runs perfect. Could gas be sucked thru the accel pump system into the Holley.jpg Venturies causing it to run way rich?
 

·
Registered
Joined
·
913 Posts
X2 on what dfwcatsclub said. What I have seen is that when the metering block gasket is leaking the idle mixture screws don't do anything...which is your case.
Hopefully you tightened the power valve against the metering block.
 

·
Registered
Joined
·
8,194 Posts
Reason #6 of "Why I quit using a Holley carb and installed an Edelbrock instead"......
 

·
Registered
Joined
·
304 Posts
Discussion Starter #8
Reason #6 of "Why I quit using a Holley carb and installed an Edelbrock instead"......
I am starting to think about going that route. When i put the old bowl on everything good. I can adj carb so i think the metering block gasket is good as well as power valve. It has to be sucking gas thru the accel. pump. That is the only thing different from bowl to bowl.
 

·
Registered
Joined
·
913 Posts
My Holley 4160 600 cfm carb started leaking out one of the dime sized plugs on the fuel bowl. Called holley and got a replacement bowl. And rebuild kit. I did not rebuild the carb Just used Bowl gaskets, power valve, needle and seats, accel. pump. Carb was perfect before leak. Problem now is it runs way to rich, black smoke out tail pipe. Rechecked float level and perfect. Adjusting idle mixture screw does nothing. What am i missing here? These bowls are so easy to replace i didn't even take the carb off the intake manifold. I did both primary and secondary bowls.
Clean your old bowl, add JB Weld and go with it.
 

·
Registered
Joined
·
708 Posts
The rubber check valve has nothing to do with the symptoms you're experiencing. Did you install the correct ring gasket between the power valve and the metering block? Did you install the correct gasket between the metering block and the main body? It sounds like an internal leak at the power valve or between the metering block and the main body. If it were me, I'd go through the complete rebuild process and start over with a new Holley kit. Buy a gallon of carb cleaner and soak the body and all the parts in the bottom half of a gallon milk jug. Take your time and learn about the carb and you'll be much better at dialing it in perfectly and diagnosing future problems. I much prefer Holleys over Carter AFB/Edelbrock carbs. I could never get my AFB with the Street/Strip metering rod/jet kit dialed in as well as the Holley.

Regarding your original fuel bowl...
The staked in plugs that are leaking are common problem on Holleys, but can easily be fixed with JB weld. I've seen articles that recommend covering all of the staked in plugs with JB weld on brand new carburetors. The JB weld repair can last as long as 10 years.

If you're familiar with Holleys and really want to go with a new carb instead of rebuilding your current Holley, check out Summit's new 600 CFM carb.
 

·
Registered
Joined
·
11,950 Posts
Double check that power valve is good - sounds like a classic blown one.......and yeah, it's easy to get the gaskets wrong if you don't watch it closely. I think there are 2 variations....
 

·
Registered
Joined
·
304 Posts
Discussion Starter #12
Double check that power valve is good - sounds like a classic blown one.......and yeah, it's easy to get the gaskets wrong if you don't watch it closely. I think there are 2 variations....
I thought that too but when i put the old bowl on i used the same gasket and power valve and now it is good. Talked to an good carb guy in town and he said if it is sucking thru the accel pump you should see gas driping from squirter at idle.

I diid look at that summit carb, Wonder how they perform for mostly daily driver?
 

·
Registered
Joined
·
11,950 Posts

·
Registered
Joined
·
708 Posts
I thought that too but when i put the old bowl on i used the same gasket and power valve and now it is good. Talked to an good carb guy in town and he said if it is sucking thru the accel pump you should see gas driping from squirter at idle.

I diid look at that summit carb, Wonder how they perform for mostly daily driver?
So far the Summit carb has worked excellent as a daily driver carb. I've been very happy with it.

Check out this article to see the differences between the two types of power valve gaskets and the different style of power valves.
http://www.chevyhiperformance.com/techarticles/74058_carburetor_valve_problems/

I've also had an issue in the past where the blue style Holley gasket between the metering block and the main body leaked internally. This caused the same symptoms you described. I found an older style brown Holley gasket at an auto parts store and installed that. It solved the problem. You could see fuel stains on the blue gasket where the fuel shouldn't have been touching it.
 

·
Registered
Joined
·
11,950 Posts
If that is in fact whats happening it's likely due to the metering block being warped - not uncommon, you can sometimes file them flat enough, but replacement isn't horrible either - I prefer the blue gaskets by a long shot! Those old brown ones stick l like nobody's business and are a real mother to get apart should you have to....
 
1 - 15 of 15 Posts
Top