well i pulled the motor apart to day and im very happy.
6.5 hours on the tiny tack and i did have an outing with out the tinny tack so the motors one around 7.5 hour on 90 full wot.
inside the head the bore is sweet you still can see the cross hatching the head is not shinny at all, the ring gap is sweet and all looks nice new.
with my off road rc around 7.5 ours equals over 15 tanks and most times the motors would be worn down by then, i think cause of the dusty conditions even with 3 air filters and the extra revs they do they just wear out and the extra heat wouldnt help.
so even thougn this motor is still got loads of life left while ive got it apart i will replace the ring and gudgeon bearing and wach in some new gaskits, i also have ordered a 257 carb causei don't like the 813 leaking fuel into the hull.
so i think this motor will be fine for another 7 or so hours of full wot and im happy its like new.