So i'll be doing a bit of a rebuild on the NC35 racebike I've acquired, depending on condition I'm hoping to do just the rings and main bearings if the pistons are looking good and the valves as well. Everything was pretty new in this engine some time ago and it has done little work.

In exploring online for the parts, it seems the pistons are not in stock anywhere? Anyone able to shed some light on where to get these if they're needed?

If it were me I would compression test it first.. these bikes dont burn through rings very quickly, nor pistons unless they have been seriously abused and in that case you'd probably need a rebore and oversize pistons which are unavaible too.

Even well abused road bikes that have been revved to the limiter all their lives often see 100,000km or more as long as they have oil and valve cleareances done.

There are occasionaly cosworth / special order cast pistons around but they seem to fetch 1000 gbp a set or more I think.

Unless its known to have a problem i would get it running and see how it sounds / dynos and try it before spending a serious amount of cash stripping and rebuildng it.

Theres a reason theres an NC30 engine on ebay right know only at 10gbp with "knocking issues" due ot the pain they are to parts and rebuild.

Form the sound of your motor if its already refreshed id definalty want it running and try / dyno it / compression tests before thinking of stripping it down.. maybe some seasons worht of racing in it sitll.

Wow. I bought all new rvf pistons and rings not so long ago and put them in two NC29s. How quickly things change.

The L NC29 pistons are still available if they would fit?

https://www.davidsilverspares.co.uk/par ... 101MV4000/

Yes I was digging around on the web only last week and dropped on cbr pistons for sale.

Top find! Champion.

greggo wrote:Wow. I bought all new rvf pistons and rings not so long ago and put them in two NC29s. How quickly things change.

Probably not been made for quite a long time just remaining dead-stock at the factory, a lot of panels and other odd bits for old bikes are often still avaible but usually only a handful of each left.

I understand fitting NC35 pistons to an NC29 will bump the compression, fitting NC29 pistons to an NC35 will have the opposite affect.