Hello James, and welcome to the Forum.

If it's a genuine Rothmans bike it's an MC18 R4J, and that's 1988. You need to identify the bike correctly though, as some 88~89 parts are interchangeable, but you will mainly need to source parts from the correct year.

TYGA Performance are based in Thailand, and do all sorts for the NSR's, but the parts availability for the older models is becomming more and more limited. Pistons from the MC28 will work though, and the spares situation is by no means at critical levels, but just remember it's a 19~20 year old model now, so you're not going to just walk into a Honda dealer and buy parts over the counter.
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Andy.
NSR-WORLD.COM

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