Ted in NE-OH

Well-known Member
I have a craftsman 15 HP garden tractor with a Brigs OHV engine , getting a lot of gas in the oil. Any idea where to start looking.
 
That can be caused by several sources.

If it has a gravity flow fuel system, could be the carb flooding, needle and seat not fully closing letting fuel drain into the engine while it's shut off. Symptoms are fuel loss or empty tank after storage, liquid locked engine when trying to start, engine flooded when trying to start, black smoke when first started.

Or if it has a fuel pump, the diaphragm can leak fuel into the engine. May or may not show symptoms, depending how bad the leak, but can cause rich running, or fuel starved under load.

And a rich running condition can do it. Choke not fully opening, flooding, clogged air filter. Symptoms are black smoke, poor fuel economy, poor performance.

Whatever the problem, it needs to be addressed ASAP, not good for the engine!
 
If the carburetor has an electric solenoid on the bottom, it is probably not shutting off the fuel to carb and you are flooding the cylinders with gas. Very bad for the engine. Add a hand shut off between tank and carb, shut off valve after using, maybe even run till it runs out of fuel before parking. That's how I solved my hydro-locking and oil dilution problem. gobble
 
Wow, you covered about everything. One goofy thing. My little JD 160 Has the tank under the seat. Put a brand new gas cap on it in the very late fall. Had winter blend gas in the tank. In the spring after a couple of really warm days,,,I went to start it and move it to another location. NO WAY! Not only was she locked up, the crank case was to the top of the dip stick. Also the gas tank was bone dry. Had to drill a very tiny hole in the gas cap. It was never drilled. Problem solved. The expanding gas had very persistently pushed all of the gas into the engine. Never had the problem again.
 
Ted,
I've seen a few briggs carbs that have a slow leak in needle. The solenoid in carb only shuts off gas to the main jet not to the carb.
I've tried many things, cleaning carb doesn't seem to help.
Either buy a new carb or install an in line solenoid shutting off gas to carb. Those leaky carbs must have been made by the same people that made Tecumseh leaky carbs.

I've installed solenoids of briggs, Jubilee and Farmall. They work, got mine off ebay.


A cheaper solution is to install an in line manual shutoff, but forget on time and you will be changing oil.
 
I had one that the carb would leak into the engine when it was off. Never had to choke it, but would eventually dilute the oil down with gas. I simply added a fuel shutoff between the tank and the carburetor.

Donovan from Wisconsin
 
If this engine has a fuel pump, that's the first place I'd check.
Have seen a few of them (fuel pumps) with leaky diaphragms.
 
if have fuel pump can leak thru there,and also can leak thru carb, or sometimes like last week one in shop was leaking both places.
 

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