Hey guys I have about a gallon and a half old O.S. 91 with a c-spec head and carb. I'm having some major problems with the engine and hoping I can find a solution on here. Engine ran great for about 20 flights, then the high needle decided it was going to back out about 60 ft up. My first auto wasn't too bad, but I did end up with a soft boom strike which somehow didnt damage the blades.

Yesterday was the first day I tried starting it since the crash, and I got it to act like it wanted to fire, but never run. I tried for hours. Today I tried again, she started after just 5 seconds on the starter, spooled up fine, sounded great, then I tried hovering to see if anything was out of whack. About 10 seconds later the engine slowly started dropping RPM. I was loosing headspeed so I brought her down, went to idle and then it died. Fuel was sputtering out of the exhaust, so I thought it was just too rich even though it lost rpm slowly like it was lean. An hour of trying later and I cannot get her to turn over, not even a pop. Any suggestions?

It was the glow plug. It glowed fine, but didn't turn over the engine. Now I'm running into even worse problems. The engine is running so rich it can barely spool up, and after a few minutes it overheats, dies, and the engine is so hot i can't even touch the needles w/o getting burned. All of this while it is running sloppy rich!!

It gets even better. I took apart the engine and the piston and head is fried. All of this while there was fuel sputtering out of the exhaust it was so rich. I'm guessing detonation, but have no idea why.

When you mention "fried", do you mean carbon? Rich running will cause carbonizing, especially with castor oil fuels, but it won't hurt the engine. If the compression is down, it's possible that the fit was damaged at some point by an accidental lean run, foreign matter, problems with breaking, and so on.

After a crash, crank, case, rod, and other parts can become deformed, which would also lead to running problems.

This is what I mean by fried. It took the engine all of 10 minutes of hovering to get this way, the whole time fuel was sputtering out of the exhaust it was running so rich, no bs. There is no binding at all and the heli ran smooth in the air, even the blades are fine after the very mild boomstrike. I just don't understand, and all my buddies are stumped

From your pictures, your engine wasn't "fried", but had some kind of foreign object run through it. The plug could have dropped an element, a bearing could have had a partial failure, something could have been sucked into the engine, and so on. Only a full rebuild will fix the problem. If it's sent to the service center, we can check to see if something in the engine caused it, but if the cause was external, the warranty wouldn't apply.