Thanks for all the information guys. I think the milleage is REALLY high, but got the bike for a real bargain (Equivalent of 250 pounds) and it actually still runs very well for it's age. I was really hoping to just replace the rings as I would have to find an engineering company who can do a rebore for an oversized piston, but it seems that it might be the obvious solution to do so.

The Yamaha dealers around here charge an arm and a leg for parts, if they can still source them (and if they are prepared to help as customer service sucks in this country) so I agree with you Mezo that I'd rather try and see if can find an oversized piston and someone that knows what they are doing when it somes to reboring the engine....will be nice to have a bit more power from the old muel.


The price of the Wiseco kit is really not bad seeing as replacement rings for the existing bore and piston will cost me half as much, so it might just be worth the effort. I'll also just respray the block with black engine paint while I'm at it to give it a new look....all the paint has sadly dissapeared over the years.

I am aiming to rebuild this bike completely but it completely depends on funds and time at this stage. I also use the bike quite regularly to get to work and back so that leaves me without transport for a while.

Thanks for all the VERY helpful information guys. I really appreciate that I can come and ask for advice from people who know what they are talking about.