Originally Posted by Greg58
Two of my three engines are from eBay, both are fairly good. One is almost 3 years old with no problems. As long as you prep the engine before installing it you should be OK. A lot of new builders are worried about warranty, but I like a lot of members here on the forum pull a new engine apart and make sure everything is cleaned out from the factory. I do a little porting before it ever goes on a bike.
My oldest and highest mileage engine was bought on ebay from boygoesfast back in the fall of 2009 and its still running great, not a real high mileage engine but ithas well over 2000 miles on it now.
Its a lot to do with setting it up right, using a quality oil and the right mix and dont try to blow it up or you will....