stopcock/intake vacuum line

[John Jordan]

What is the cause for the intake to stopcock vacuum line to get moisture, (fuel), in the line while running? Is it coming from the stopcock leaking through the diaphragm, from the intake nipple due to to rich of a gas supply through the carburetor,? The exhaust is very rich! You can see the unburnt fuel, gray smoke, in the exhaust as well as the strong smell of unburnt fuel.

Please advise.

Thanks for any advice on possible cause and or remedies for this problem.

John J.

[kz1000st]

It could be that the diaphragm in the petcock is leaking. The easiest way to find out is to remove the hose from the intake and suck on it. The taste will be a dead giveaway. If it is leaking, a replacement should cure the problem.

[John Jordan]

Thank you so much!

I agree with your opinion and thought it must come from the petcock since the intake nipple is a vacuum source and any fuel from there would not go upstream of the vacuum rather stay in the intake and into the engines combustion chamber.

Any ideas on how to reduce the richness of the fuel supply to the combustion chamber. Is that a float bowl level issue or other carburetor related adjustment?

J.J.

[John Jordan]

I did, as you suggested in my 1st question about this vacuum issue. I pulled the gas tank and checked for water contamination in the fuel. The tank and fuel were fine and I only found a little rust in the tanks bottom. I used a hand full of large nuts and rattled them inside the tank to remove some of the rust. At any rate I re-cleaned the tank and fuel lines even though there was no water in the fuel system.

I live on the Atlantic coast and I know all about the ethanol and it being hydroscopic, absorbing moisture, from all the problems we boaters are having with ethanol gasoline. Most locals use straight gas in their gasoline motors, especially boats with inboard tanks. Most all of the salt water marinas sell non ethanol gasoline. It is a big problem especially if you own a 50' gasoline powered boat with inboard tanks. Its a job to remove an inboard fuel tank from a boat's hull especially if you have a cabin or even a center console to contend with. The removal the boats structure to gain access to the inboard fuel tank is often to costly to be worth doing.

[kz1000st]

I would first make sure the vacuum hose to the petcock issue is cleared up. You may have crud under the float needle flooding the engine while running. A simple fix may be running Seafoam in the gas. If you do that a good run of 45 mintes might just clear up the problem.

[blueboy5000]

If your fuel tank is HIGHER elevated than the carburetor, I'd eliminate the vacuum petcock entirely and install this, as I have in every application where the tank is higher than the carb:

http://www.amazon.com/Briggs-Stratton-698183-Shut-Off-Selected/dp/B0038U3JKM

Works great, just remember to close it ;P