After over 7 gallons, my TRX 2.R was hard to tune and a lot of oil was on the front bearing. Compression is good, I have measured it using a compression gauge by Hobbico (17 psi).
So I opend the engine and I found several scratch on crankshaft (see the photo). Also scratches are inside the crankcase.
Inner bearing has same axial play, the front bearing is ok without play.
Have anyone some experience or idea about it? New crankcase, crankshaft and bearing are needed?
That is caused by dust entering the engine and will cause leaking out the front bearing, so long as you dont mind a messy front bearing it really wont matter a whole lot, unless its that bad that its sucking air?
As for rear bearing play, its typical of Traxxas engines to have a small amount, ive never seen one that doesnt have that play, if you have the money look up TKO Ceramic bearings for the 2.5/3.3...