18hp B&S gas in cylinder

[Jerryb]

Mower was hard to start so I took out the spark plug and gas flowed out of the cylinder. I got mower to run. There was blue smoke on start up but then it ran OK. The following week, it would not start. There was no gas in the gas tank. It drained into the cylinder. It seems like gas in the oil and oil in the cylinder. Do I have a bad valve or seal? Help.

 

[CourierDriver]

float could be not shutting of the gas in the bowl if its got one.

 

[bepperb]

Is the gas tank above the cylinder and fed by gravity? Then I would assume the float is not floating or the needle the float actuates is no longer making a good seal for some reason or another, usually sediment or varnish. Both these things are in the bowl of the carburetor and fixed by a rebuild of it.

 

[BigCahuna]

I put a shut off valve on mine after that happened to me.,,

 

[J. A. Rizzo]

Another vote for a stuck or deteriorated float or needle. Sometimes the float deteriorates and floods, leaving gravity to overfill the carburetor and letting it all spill into the cylinder. A good carb cleaning or new float should fix it up.

 

[olddognewtrks]

I had the same thing happen when I changed out the old cracked gas line. I assume I broke loose some crud. Drained a half gallon of gas into a half gallon crankcase. Cold oil flowed out VERY well. Happened again a few days later. REALLY cleaned everything, again. Runs well, seems fixed, but chickened out and put a shut off valve in the line. At least now I can run it dry for storage.

 

[Jerryb]

I took apart the carb and it looks very clean. Float works. It got dark before I put it all back together. Tell me about the shut off valve. Where can I get one? Thanks

 

[MNgopher]

Any shop that supplies small engine repairs or parts should have one available. Just a valve that spices into the fuel line. We have a lawn tractor with a 17hp B&S that had the same issue. Rebuilt the carb and added the shutoff switch to keep it from happening again. No problems since...

 

[countryboy9799]

http://www.amazon.com/Briggs-Stratton-Shut-Off-Valve-5091H/dp/B000KKIJW6

http://www.amazon.com/Briggs-Stratton-69...5172&sr=8-1

Just get the right size hose and your set. Any hardware, farm or small engine store should have one.

 

[Jerryb]

Thanks, I picked up a shut off valve and no more oil in the cylinder. I put everything back together and I misplaced a spring for the carb. I'll report back when I make some progress. Thanks all for your help.

 

[Jerryb]

Everything is re-assembled and mower is working. I finally cut the grass after 2 weeks. Thanks for all your help. I'll be back when something else fails or if I can help someone else.