ORIGINAL: opjose
To add to Montague's post...
If you ever do have an engine full of mud, take off the carb and glow plug, and flush the engine with that half gallon of glow fuel left over from last season.
Use a sprayer and paint brush to get at the outer surfaces and flush, flush, flush until all of the debris is gone.
I've even resorted to first flushing the engine out with water ( which is better to desolve the mud and debris ) then immediately follow that with copious amounts of old glow fuel to get rid of the water, etc.
Then I slowly rotate the crankshaft trying to feel any resistance from "grit".
If everything turns smoothly, it gets yet another flush and is put back together.
I haven't had a problem with this...
After my mid-air my engine was completey under ground in the mud. I got it home and took off the carb and the glow plug. I didn't need to take the muffler because it was sheared off at the muffler extention. Anyway, I soaked the engine in water to get the dried dirt wet again. After it was wet I sprayed it out with the hose. I turned the crank slow to feel for risistance and sprayed more until all the dirt was out. After that I blew out the water with an air compressor. Then put after run in the engine and turned it a few more times with my starter. Filled up the gas tank and started the plane. It never skipped a beat and it is still running great. Just my 2 cents worth