I have an OS 120 4 stroke, the fuel pump is bad, My other 4 strokes have no pump, so I have never used an engine with a fuel pump ***so why the pump? What is the difference, with or without the pump...... why can't I just eliminate the pump like the others?
Any experence with this anyone?
george

Stick a Perry pump on it?

Typically the factory pump engines have a larger carb than the non pumped ones. The engine will not draw fuel correctly. Also the OS's have a demand regulator on the carb and it'll just never work without a pump.

You could buy a regular carb and put on it?

Enjoy,

Jim

The pump engine gives you the option of mounting your fuel tank near the CG, since tank position becomes non-critical. Also the pumper will not tend to lean as the fuel supply burns down, so engine performance will be more consistant throughout the flight.

OS replacement fuel pumps cost a small fortune. Buying a regular carb and a new backplate would probably be the most inexpensive way to go.

which model is it? Is it a Surpass II or III?

Just curious. It is not easy to place a regular carb on a pumped motor. The backplate is different, etc. I may try it, as I have a 120 surpass II with a questionable pump and carb.

I am even thining of getting an elbow and carb for a magnum 120. Much cheaper, and can't be that hard to match up...

If I do it, I'll post the result here.

Bill

Some guys at my field said that they loved to buy these engines and just remove the pump or use another carb on them and they ran great. Can't remember the details. If it were summer I could ask them for you.