Is it necessary to remove the engine to do a piston replacement on an RT3?

I dunno but it's not usual, so long as the head and barrel will come off. More commonly a problem with four strokes due to large cylinder heads.

I dunno but it's not usual, so long as the head and barrel will come off. More commonly a problem with four strokes due to large cylinder heads.

Thanks for the reply Oldgit, hopefully I won't have to find out soon. I looks like it would be very close on the cylinder.

I'm trying to get it running for a friend, delivered as a basket case!

Looking into the exhaust and spark plug holes I can see what looks like cross-hatching on the cylinder walls, but it is pretty rough and irregular looking. The bike only shows 5,000 miles on the clock, but I'm wondering if someone has been into the motor already.

Will try a compression test tomorrow, and see if it will fire up.