20HP Briggs twin pukes gas.

exendogirl

New User
Working on a Briggs & Stratton 20 HP 2 cylinder flathead. The thing cold starts easily, stumbles a bit, clears momentarily, the pumps gas out the top of the carb. Suspecting a stuck float, I pulled the carb off, cleaned out the float bowl, all the passages, checked the float for leaks and re-assembled it. Same thing! What am I missing?
 
Working on a Briggs & Stratton 20 HP 2 cylinder flathead. The thing cold starts easily, stumbles a bit, clears momentarily, the pumps gas out the top of the carb. Suspecting a stuck float, I pulled the carb off, cleaned out the float bowl, all the passages, checked the float for leaks and re-assembled it. Same thing! What am I missing? IN
The best way to check if a plastic float is saturated is to put it in a vice and squish it. If gas comes out of it you will know it was saturated. Before you do this test BE SURE YOU HAVE A NEW FLOAT, preferably a brass float to install in your carburetor.
 
The best way to check if a plastic float is saturated is to put it in a vice and squish it. If gas comes out of it you will know it was saturated. Before you do this test BE SURE YOU HAVE A NEW FLOAT, preferably a brass float to install in your carburetor.

''The best way to check if a plastic float is saturated is to put it in a vice and squish it"

I'm not so sure about that, a float scale as shown below is considerably less destructive, compare the weight of the old float to the weight of a new one, or to published "specs" (when available).

BkM7CIH.jpeg
 
I'm late to the party but have a couple of things to say.
(A) If there's not a fuel shutoff valve install one. Start engine as usual and wait for problem to begin,shut fuel off to see if at some point before engine runs out of fuel and dies it stops belching gas. If so that might point to float or needle and seat bad.
(B) Most important op return to report. That's how question askers show appreciation for question answerers plus we can learn from it.
 
Working on a Briggs & Stratton 20 HP 2 cylinder flathead. The thing cold starts easily, stumbles a bit, clears momentarily, the pumps gas out the top of the carb. Suspecting a stuck float, I pulled the carb off, cleaned out the float bowl, all the passages, checked the float for leaks and re-assembled it. Same thing! What am I missing?
Valve seat recession. Need to adjust the intake valve. To do that you have to remove the valve and remove a little off the valve stem
 
I hope exendogirl sorts out the fuel system before she starts grinding on the valves.
I hope so too. I don't understand why valve seat recession would cause the carburetor to overflow. Just saying that is the problem doesn't tell us why.
 
Figured I was missing something, so I took the carb off, and went through it again. Sure enough, there was small piece of something stuck between the valve and the seat. Completely dis-assembled and cleaned the carb again. Made sure the float actually floated, which it did. Replaced some sketchy-looking fuel hoses, installed another fuel filter. Problem solved! I DID miss something. Thanks for all, for all of your input.
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top