rugrad02

I recently put a Thunder Tiger .42 Engine that is probably 8 years old in a new ARF. The engine hasnt run it some time. I did take the engine apart to clean the insides real good a few months ago.

Today I try starting the engine using a stick type starter. When I flicked the engine I noticed a considerable amount of force wanting to turn the engine in the opposite(clockwise) direction. I thought it to be vapor lock until I did get the engine to crank. I got the engine to run nice but when I brought it down to idle, the engine flipped itself and began to run in the opposite direction. What is causing the engine to want to run in a clockwise direction? Did I somehow not assemble the engine correctly after cleaning? I didnt take the engine completely apart, just took the piston out for cleaning.

Also, is it common for an engine to leak a bit of fuel from around the propeller shaft?

Thanks,
KB

McFlyboy

Did you replace the washer under the glow plug?

If its leaking get a thin shim in behind the prop driver.
I've had 2 GP42 and both were great engines, still got one of them in a sunday hack, reliable as a swiss watch.

bingo field

Engines can leak from the front bearing. The seals are not always perfect. You could replace it if you wanted to. It sounds however like your biggest problem is it it running rich at idle. That would cause it to load up and run backwards.

Campy

My Feedback: (1)

Another possibility, you said you pulled the piston. Usually the cylinder liner comes out with the piston. Did you put the liner back in in reversed ?

submikester

My Feedback: (6)

At idle, pinch the fuel line. If it speeds up then quits it is rich, if it simply dies it is lean. Typically when an engine backfires it is because it is lean. I would check the mixture and adjust accordingly.