Its nice to have a spare engine. I've got two complete motors for my LC. I just switched to motor #2 last winter. Motor #1 ran in the bike for 3? years. Now Motor #2 will run for a few years and then I'll switch them again. This way I always have a motor ready to go and no motor sits idle for years to get rusty inside. :D
Kicking myself that i didn't spray starter fluid around carb joint to check for leeks. there had also been a little bit of oil around outside of reed block that i haden't noticed. i went over this bike for hours before running it up the road.
I had a badly leaking reed gasket and spraying carb cleaner around the reed block had zero effect. The primary symptom was an elevated idle.
Now, as a result of that experience, I use grey motoseal on all surfaces of the reed block and spacers. No leaks since.
Thing is i didn't at the time recognise the bike had seized at the top of that hill. It's since travelled another 200k's and i thought it was running great.
A friend tore down his 2-stroke enduro bike to discover a big piece of nikasil plating had flaked off. Strange thing was he never noticed any drop in performance, even though the position of the flake should have resulted in a large loss of compression. Short of a serious seizure I think a 2-stroke engine can tolerate a fair amount of cylinder/ring damage or wear and still run fine.