Alright, so this is the result of my efforts trying to see if anything was astray with my engine. I'm pleased to say that it all came apart and went back together a million times easier than other engines i've fooled around with before. A big releif!

Engine with head off



The head



The crank case doesnt seem to have any cracks in it anywhere.



Piston and sleeve, which i was surprised at how easy they were to get out cleanly with a wooden chopstick to prod the underside of the sleeve and a tiny wrench to lift the conrod gently off the crank.



something i have ZERO experience in is seeing possible wear/damage to the sleeve or piston. I've read that just by opening the engine up like this it has caused more harm than good, but i'm really not sure. All i can see is plenty of after-run on that sleeve.



and to my untrained eye, that piston don't look so bad either..



I also can't see any damage like i was fearing around the con-rod that might cause this 'clicking' feeling as it passes over the top of its rotation. With the head off, its clear to feel there is still pinch there, it lifts the sleeve out of the case, though it's still kinda easy to turn over by hand.



So. I can't see any reason why it should feel like it's clicking over at the top of it's stroke. the pin on the crank looked fine with what little i know of it...
And now that i know i can dissassemble and reassemble easily enough, i won't be afraid to replace the con-rod when i have the cash.

anyone else see anything i dont?