Boiling gas

I know that I read this one time on this site but it has been a long time ago,so need some one to refresh my memory,my problem is I was just mowing some grass this morning on my TO 20 Ferguson just up and shut down after about 1hr of mowing,checked the fuel , plenty there but it was boiling. can anyone refresh my memory whats causing this,and what I should do?

Towed it back up to garage,put battery on to charge battery back up, tried to start it again but no such luck would not even turn starter over,just guessing of course but could it be a vapor lock,if so now what do I do.

My friends to30 boils fuel, I told him I would not feel comfortable running the tractor with fuel boiling in the tank. He said it always did that if he ran it a long time, working it hard.

My TO35 has a heat shield over the exhaust manifold that deflected heat from the fuel tank. To my knowledge, I have never heard fuel boiling in the tank of our TO35 and it has done a lot of hard work over its life.

Look it up, they did make a manifold heat shield for the to20, but I guess it was an option.

If you have another coil (the same voltage) put other coil on and try it.

The boiling gas shouldn't have anything to do with the battery or starter or electrical problems. Possibly you cranked on it too long when it was vapor locked or flooded? Pull the air cleaner hose off the carb, be sure it isn't standing full of gas. Could have liquid fuel in the cylinders if it is.

The boiling gas can cause a couple of problems... Well, it can cause a really bad problem, but since it didn't catch fire, we can eliminate that one!

Vapor lock can happen when the liquid gasoline in the line to the carb boils, pushing the fuel back into the tank instead of letting it flow into the carb as it should. Some solutions are to use a steel line, not copper, route the line as far from the exhaust manifold as possible, or insulate the line.

The engine may have flooded if enough pressure were trapped in the tank to over ride the needle valve. Be sure the cap is vented.

The boiling can be caused by retarded ignition timing (check your centrifugal advance, point gap, and distributor bushings), a radiator with clogged fins not allowing enough air to move over the engine, slipping belt not turning the fan fast enough, and the above coupled with hot weather, and a heavily loaded engine.

If you can fab a heat shield, that would be one of the surest ways to remedy it.

(quoted from post at 09:53:58 05/11/15) I know that I read this one time on this site but it has been a long time ago,so need some one to refresh my memory,my problem is I was just mowing some grass this morning on my TO 20 Ferguson just up and shut down after about 1hr of mowing,checked the fuel , plenty there but it was boiling. can anyone refresh my memory whats causing this,and what I should do?

Click to expand...

ix the boiling gas problem first and asap. Last thing you want is for enough pressure to build up in the tank to blow the cap off and spray fuel all over you and the hot exhaust. Once that is fixed you will probably not have the other problems any more.

John E/Pa, did you get your issue fixed?

I had the same problem with my TO-20. I believe my problem was two parts. The first was my radiator fins were clogged. Try using a pressure washer and clean the fins from the engine side. The second part was my manifold was cracked. Give the manifold a good inspection and if there is any crack the heat escaping could be heating up your tank causing it to boil. I considered making a heat shield between the the tank and manifold but after I repaired the manifold and cleaned the radiator the issue resolved itself.