Fuel dilution on a gas engine Power Trac

[m5040]

I used my PT018 last week with a homemade leaf dozer and everything was fine. I went to use it this week and it was difficult to start with black smoke. If I shut off my fuel tank valve, it then ran great as usual. The low oil alarm was also actuating on low RPMs.
It has a carb made in Japan that looks to be very high quality. I took off the top and everything appeared fine. If I opened the fuel valve, the carb filled 80% and stopped (with engine off of course). I ordered a float kit with a gasket and needle valve (viton tipped as original).
Since the carb filled, the electric shutoff valve must be junk, only has 150 hours on it.

Anyone ever experience the vacuum fuel pumps over-pressurizing the carb?

When I get the parts, will try again. It had only 6 hours on the oil change, down the drain because I didn't shut the valve when parked.

Just a warning to be aware of the potential for this problem since the fuel tank is above the carb.

 

[MossRoad]

Never had a fuel pump over pressurize the carb on a small engine. My original fuel pump on the Kohler CH25 went bad. Price was outrageous. So I gutted it, used it as a vacuum source for an external fuel pump. No problems so far.

But that's not the problem you're experiencing.

 

[tomplum]

You didn't say if this is a Kohler as well. But typically the anti- backfire solenoid blocks the fuel pipe that goes to the venturi. Because carburetor bowls also need another vent, your fuel likely flooded via the vent passage. Low speed circuits can draw from the bowl area as well.

 

[m5040]

It is the Robin engine. Can't see a name on the carb. I am old school when carbs didn't have an electric solenoid and what looks like a stopper to cut off fuel. But since the engine was flooding out while running and was way over on the oil level, I would think it is the needle and seat. I will start there and tell myself that I will shut off the fuel at the tank every time.