I have a question for the engine guru's of this forum.
I have an RCS44B2 (Moki) twin.
In the first flights of a new 83" Fly Baby bipe I just completed, I lost the prop. Four of the six mounting bolts were missing and two sheared. The engine quit before I could actuate the cut off.
The next day, after replacing the prop and bolts, the engine ran ok for a few minutes, then blew the spark plug out of one of the heads. I replaced the head with one from an RCS140 that has the same cylinder as the twin. I had a lot of trouble getting a seal at the new head.
Now the engine will run OK at top speed but I cannot get it to idle at less than 2500rpm. There seems to be a lot of black stuff coming out of the exhaust. The throttle cuts the speed when it is reduced only about 1/2 of what it previously took for the idle.
I am using 50:1 oil mix with Penzoil 2 stroke oil. The prop is a 22-19 Zinger cut down to 20". I get about 5500rpm at top speed.
Do you think it should be torn down and examined? What should I look for?
I hate to take it apart- there are a lot of screws in that engine.