Frustrating B&S 17.5 HP surging and dying problem

Hello all, I have a Troy Bilt #233644 riding mower. The engine is labeled 6BSXS5012.VP and 276470. When I first bought this (used) mower, it ran well until I engaged the PTO. A Sea Foam cleaner treatment fixed that for a couple of weeks. Now, the problem is back and is much worse. The governor rocks back and forth quite a bit, I have attached a picture of the parts that move constantly. I am extremely frustrated and cannot afford a new mower.

So far I've done the following to no avail:

• replaced the fuel filter
• replaced the carb with a new Briggs and Stratton replacement
• ran it without an air filter to see if that is the problem
• ran it without the fuel filter to see if that is the problem
• added carb cleaner to the gas again, the gas is 89 octane, pretty fresh

:welcome:

Most likely you have a blockge in the fuel lines and or tank.
If the mower has a fuel pump, the diaphragm may be punctured or the air vent blocked.
All of which will reduce the fuel flow to the engine.
Confirm this bu rigging up some sort of alternate fuel tank suspended above the engine.
It does not need to be big and old walk behind fuel tank will be fine.
If the engine runs properly then there is a problem with the fuel delivery.
I you pull the fuel line off the carb, hold it upright and crank the engine it should pump out about 1" higher than the end of the tube.

Yeah, fuel starvation. Could be something as simple as junk in the carb float bowel.
Fact that SeaFoam helped it temporarily points to that.

Walt Conner

Tinkerer200 said:

Yeah, fuel starvation. Could be something as simple as junk in the carb float bowel.
Fact that SeaFoam helped it temporarily points to that.

Click to expand...

I have a literally brand new carb in there now.

Also, I don't believe that it has a fuel pump as I see a direct line from the fuel tank to the carb. The fuel gushes from the fuel to the carb with some authority, I haven't tested it but it seems good.

Well, I think I fixed it. I swapped out the solenoid cable from my old mower and changed the air filter, the mower still stumbles a bit on a cold start but ran strong with the PTO engaged and my son (wearing hearing protection as did I) in my lap. There was a bit of uphill mowing too.