- As already mentioned, the correct piston should be used, however given that these bikes are circa 30 years old, there are often occasions where you may come across re-plated barrels, so the sizing can be incorrect.
Providing everything is original as Honda intended, the recipe is as follows:
"A" barrel - "B" piston
"B" barrel - "no mark" piston
"C" barrel - "D" piston
Don't ask me why! 🤣🤣🤣
- Do not mix "H" and "L" heads and barrels.
"H" parts are R model
"L" parts are SE/SP model
You can, if you are desperate, fit an "H" head to an "L" barrel, but it will have very low compression, and a significant loss of power.*
There is no rule against using an "R" head & barrel on one side, and an "SP" head & barrel on the other, but really, just keep it simple. Use either "R" or "SP".
DO NOT be tempted to fit "L" heads to "H" barrels, thinking high compression will give you loads of power... it won't! It will however put a big hole in your wallet when the heads melt and pistons fuse to the barrels! Even in completely stock configuration, the compression is borderline, and I've seen dozens of (maybe more) front heads with signs of detonation. The setup really is well optimised from the factory on all models.
The NSR is extremely sensitive to compression changes, and for virtually every scenario the standard setup is perfect.
_________________
Andy.
NSR-WORLD.COM
Please keep all responses to Forum posts on the Forum so that others may benefit.
Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.
Check us out on Facebook! Please "like" our page!