I just picked it up.
it idled perfect for ages! and ran very well.
the piston and sleeve look perfect and it feels to me that it has HEAPS of compression.
as it gets higher u can reallllly feel its pushing the air.
its clean and the heat sink is not scratched at all..
It looks to me to be in near perfect order.
The guy who sold it was a racer and has been into R/C cars for 3 years and the engione is around a year old, so i guess he knows how to run in an engine pretty good.
thanks for your help all