powrguy

Okay; here's what I've done so far:

I've got an Onan twin on this thing (B43M), and it just quit running. It acted like I had run out of gas. I removed the fuel line at the fuel pump end, and gas was pouring from the hose ok. Then, I thought maybe the fuel pump had quit, so I took another intake/carb/fuel pump assembly I had from a B43M blown motor, and it did the same thing (not starting). It WILL start with a squirt of gas in the carb throat, but when that squirt is burned, it quits.

Additionally, I checked compression on both cylinders, and they're above 110psi each. I put two new plugs in, and still no go.

I have no idea what to do next. Having swapped out the entire intake manifold, carb, and fuel pump, and STILL having the SAME symptoms is driving me nuts !

Any ideas where to try next?

GravelyNut

Are you removing the carb and checking the gasket under them. Sounds like you have an air leak. Worse case is that you have two manifolds that are splitting due to the epoxy breaking down on the two sections. We have 2 8162-Ts that are 2 serial numbers apart.

powrguy

It's strange to me that I have fuel into the pump/carb fitting, but no apparent fuel flow in the carb. Squirting gas into the carb will get it to fire up, but it won't run normally on its own.

I swapped the manifold/carb/fuel pump assembly from another motor, and it still had the same problem. Seems odd that the problem would be identical, when I swapped all the parts out. If it woldn't run at all, even with the gas sprayed in the carb, then it would appear to be ignition, although spark seems good.

It was running fine and just died, as I said, as if the fuel tank had emptied.

powrguy

I have the Gravely running again !

The problem was the fuel pump. I had swapped the whole intake/carb/fuel pump yesterday, but in my wisdom, decided the current fuel pump looked like it had a larger vacuum tube orifice, so I re-used it on the other carb. I came upon the idea that MAYBE that would be the only component common to the problem after the swap, and changed to the replacement fuel pump this morning.

It fired right up, but had a leaky carb cover gasket, so we swapped to the original carb, using only the replacement fuel pump, and it's running fine.


thanks

GravelyNut

Nothing beats the sound of an Onan twin running.