Time for new piston?

[mfordy]

When is it time to rebuild the top end on my boys KX65? Bikes done approx 60hours since last piston by previous owner (great bike John but the number 13 had to go!..) and is still going strong. Still starts well and has plenty of boogy when in the powerband.
Is it worth doing a compression check or just go ahead and rebuild?
What's the risk of leaving it for another 20~30 hours?
He is now getting on the pipe regularly and is motoxing most weekends.

Still relatively new to 2 strokes so sorry if this is a dumb question.

[B0000M]

definately time for a new one. id suggest 30 hours tops for a set of rings, 60 for a piston. if its on the powerband most of the time

[bogan]

yeh prolly time for a new one, I do the piston every second top end rebuild (rings every time of course).

[B0000M]

added bonus, he should notice the power increase!

[mfordy]

Thats the thing - I don't think its down on power because luckily(?) I'm short enough to be able to ride these little rockets and his brothers '08 KX65 which is still pretty fresh is no quicker!..

added bonus, he should notice the power increase!

[noobi]

do a compression test and compare the two readings. i dont know what it should be though. but if there different by quite abit then it probably needs a piston or ring or both