Simono, you'll have to get your cylinders replated as Honda do not make cylinders anymore for either the NXA or NX5 RS's.
Maybe Padgetts have some new ones as old stock?
As a side note, the markings on one of the cylinders on my RS suggest it has been replated four times!
Now, I may get shot down for this, but here goes...
With regards to cylinder plating I have just had my RS cylinders replated by Aptec. I have not used them yet (ahem...*cough*) so cannot comment but they are 'round' and the piston / bore clearance is correct.
I have also had MC21 cylinders replated (twice) by Langcourt and never had any trouble.
According to IanE cylinders should last a very long time unless there is major damaged or have been replated 'X' amount of times. Same for crankshafts, they will last many miles longer than stated by HRC. But and this is a BIG but how long do you run them before you replace them??? It would be nice to replace them every 1200 miles but how many RS riders in the NG /ACU National 250GP Championship replace the cranks at 1200 miles??? It would be interesting to find out!
The crank on my RS has unknown mileage, according to the former owner (who never kept any notes about the bike but that is another story...) there is 'around' 500 miles on it. Yeah, I bet thats right! The crank does 'feel' good and all bearing run smooth as silk so I will use it for the mean time. The crank has also been apart at some point and has plastic stuffers fitted to it, so it could even be an old crank rebuilt!
I'm only using my RS for track days (at the moment...) and the way I ride I doubt any of the above will be of relevance until I'm a very old man!
As for pistons, I'll be using HRC pistons and rings as long as I can buy them.
P.S. Samba exhausts... luverly!
Last edited by sennidott on Fri Aug 31, 2012 8:25 am; edited 1 time in total