gasshutoffvalveissue

L

lakeside

Senior Member
Last fall before storage I closed the shut off valve and ran the engine until it sputtered. (I also have an electronic shutoff). Two days later noticed carb was leaking. I let it leak all winter. Yesterday I cleaned out the sediment bowl, drained the tank ,refilled and drained several more times until no further sign of debri in gas. Started car.
Gas still leaks from carb when engine is not running. Here's the question. The problem is,more than likely, a faulty manual gas shut off valve. But why wouldn't the electronic shut off stop the gas? Could both devices have failed simultaneously? Car is early 31. Thanks.
 
doesnt take much rust or crap to stick a needle valve and gas has a great tendency to have capilary action so it takes a fraction of a fraction of an inch to let it by.
 
Sounds like you have 3 leaky valves now. My 29 Tudor leaked a full tank of gas over the winter when I first bought the car, so I lapped the tank valve and the carb needle and seat. They are holding perfectly well now.

BTW, this thread will never be found by searching the title with the words all connected.
 
T.Wesenberg reply#3..
Forgive my ignorance but what does ''lapped the tank valve'' mean? I'm going to replace the manual gas shut off valve because I suspect their isn't a screen on it otherwise how could debri get past. Thanks.
 
SeaSlugs..reply#2
Are you thinking that the debri caused both the manual and electronic shut offs to fail?
Thanks for the reply.
 
lakeside said:
SeaSlugs..reply#2
Are you thinking that the debri caused both the manual and electronic shut offs to fail?
Thanks for the reply.
Click to expand...

That would be my best guess. Manual valve gets grooves worn in it over the years as rust flakes are harder than the brass, Tom mentions lapping which takes a very small amount off the valve and the seat so it makes 100% contact again (thus doesnt leak). I would install the fine mesh pencil filter that sticks in the top of the shutoff valve and take the electric valve off and spray carb cleaner thru it hopefully getting whatever is stuck out of it.

As a test take the gas line off the carb and put a bucket under it. open and close both manual and electric valves and make sure no gas comes out.
 
You can use some fine valve grinding compound applied to the taper, then spin the handle around to lap the two parts together for a gas tight fit. Of course to do this you take the valve apart first. The handle might also need a new packing to seal it.+
 
Make sure the direction of the stem is right for the flow when you reassemble it. Don't ask me how I know!
Terry
 
ALMOST FORGOT. Do I need any gas resistant packing grease when the manual gas valve is reinserted into the tank or is the pipe thread sufficient? Thanks.
 
Dis assemble the electric shutoff solenoid. It tends to get a "shellac" type film on it and not function correctly. FWIW
Paul in CT
 
You must log in or register to reply here.
Back
Top