657 rotax problems

[buxtonous]

ive got the above which used to start fine and tick over and do evrything as it should of untill last sunday....
took the ski out ran for about 400 yards and just died and the battery would not turn the ski over so i took it back in hooked up some jump leads and it would turn over and spark but not start, so i went in head 1st and pulled the engine to find that the rotary valve had a chip in it and was stuck covering half of 1 intake and covering the whole of the other intake and it was locked under the chip.
what my question is how much of the engine should i rebuild as its currently out of the ski bearing in mind it used to run fine untill the valve stuck??
the ski currently has 110 + 115 and i have sorted the rotary valve and the chip.
thanks alex

 

[Dr Honda]

If the rotary valve stopped spinning... and your compression is that low... then it's time for a full rebuild.

Let me ask you... did you convert it to pre-mix, and remove the oil system?

 

[buxtonous]

Hi thanks for ur reply, but i hear ya on the time for a rebuild im guessing that the engine has never been striped down as all bolts and nuts are almost welded in! i losened of the head studs which required a breaker bar and did result in breaking two :ack: not nice!
there are quite a few sheared off nuts and bolts around the whole engine and home made gaskets covered in goo around the place. so i think you are correct in saying so. what else could cause the valve to pick up on the edge of the port apart from something in the engine???