OS 40 engine problem

Get with a mentor, and have him show you how to run a 2 cycle engine. It is mostly by sound, and no one here can tell you what you need to be hearing.

Is this the engine that was frozen? Seem to remember something about a PT-40 and a frozen engine. Unless the carb (assuming its the same one) was dismantled, there is going to be crud in the spray bar and probably all of the fuel and air passages. Try a new glow plug first as its the easiest thing to change. Still running poorly, you will need to clean everything out.

On 10/31/2003 8:31 PM Ted shuffled out of his cave and grunted these great (and sometimes not so great) words of knowledge:

You said you restored a PT-40. I am assuming the engine came with the plane. Your description sounds like the engine is running lean (too much air and/or not enough fuel).

I will be willing to bet you did not do the following: Replace the fuel lines INSIDE the tank, clean the clunk and verify (replace if needed) that the tubing going through the tank plug is clear (also clean the inside of the tank with some fresh fuel [or acetone] to disolve any deposits). The tank is a good place for crud to accumulate if any fuel has been sitting in it for awhile. I am assuming you replaced the fuel lines from the tank to the engine AND the piece of fuel line from the remote needle valve to the engine, also from the muffler to the tank. This will insure you have good fuel flow and no air leaks in the fuel system.

Once you have done that, as mentioned in another post, remove and clean the needle valve and spray bar. After reassembly, set the idle screw on the carb and the needle valve to manufacturer's settings (needle valve should be 2 - 2 1/2 turns [I am not sure on idle screw]). Using fresh fuel, the engine should now run, and you should be able to "fine tune" it.