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Hello everyone! I am having a problem with a Briggs 12.5 IC engine (gravity fed, no fuel pump). It is mounted on a John Deere 68 RER (the original engine was a briggs 8hp). The engine runs well under load for about 30 minutes.....then it stalls and I hear a gurgling sound from the gas tank. This gurgling continues for about 10 minutes after it has stalled. When the engine cools down a bit it starts right away and runs well until it heats back up. The tank cap is free, the fuel line and filter are new. I am really stuck as to why this is happening. Hopefully someone here can help me out. Thanks!!

Feel the carb bowl the next time it happens. If it is hot, pull the shroud off and give the cooling fins a good cleaning. Sound like the engine is running so hot that it is vaporizing the fuel in the carb.

Rivets said:

Feel the carb bowl the next time it happens. If it is hot, pull the shroud off and give the cooling fins a good cleaning. Sound like the engine is running so hot that it is vaporizing the fuel in the carb.

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Thanks, Rivets! I'll have a look at the cooling fins.

Rivets said:

Feel the carb bowl the next time it happens. If it is hot, pull the shroud off and give the cooling fins a good cleaning. Sound like the engine is running so hot that it is vaporizing the fuel in the carb.

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I don't think I've heard this one before.. but it makes since good stuff

Hooks said:

Thanks, Rivets! I'll have a look at the cooling fins.

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Well, the engine is clean as can be with no other restrictions. I was thinking of lopping off the top of the fiberglass hood to let more air in and more heat out. I looked up the JD RER's that were made after mine. They all seemed to have the top of the engine exposed.

Let's see if it is a fuel or electrical problem. Can you put a clear fuel filter in to make sure that it is getting fuel when it shuts down? Also, the next time it shuts down, check immediately for spark. Your coil may be shorting out and the fuel gurgling you hear is unrelated.

Rivets said:

Let's see if it is a fuel or electrical problem. Can you put a clear fuel filter in to make sure that it is getting fuel when it shuts down? Also, the next time it shuts down, check immediately for spark. Your coil may be shorting out and the fuel gurgling you hear is unrelated.

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Hello, Rivets! I finally had some time to fool around with the JD today. I cut the top out of the hood (RER) made a few openings in the shroud as well. I went and mowed the same lot again. The engine ran perfectly. I the suppose the amount of air it was able to pull in was just not enough as the old what the old 8hp needed. Thanks for your tips.

Glad you got it going. Make sure you don't cut to much away on the shroud, as it could lead to the cooling air not being directed over the cooling fins.

Rivets said:

Glad you got it going. Make sure you don't cut to much away on the shroud, as it could lead to the cooling air not being directed over the cooling fins.

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I only cut the part directly over the flywheel. It pulls a nice stream of air in over the engine.

I've seen people hook up an electric fan from a car to the battery creates a lot of circulation and is easy to mount easy to wire. And cheap at a scrap yard