Is it ok to fit a B piston on a B cylinder? I know it should be the No mark piston that should be use on B cylinder. I have spare B pistons and trying to see if fitting it is not a bad idea?

Can anyone enlighten me about A, B & C cylinder?..I thought there only A, B & C piston.

A cylinder - B piston, B cylinder - No mark and C cylinder - D piston . I'm not sure for mc16 but I know the ns400r and ns250r has A,B,C piston
N

Measure the clearance and use whatever gives you the correct clearance; 0.039~0.045mm according to the book.

Thanks matt. Is the B pistons bigger or smaller than a no mark piston?

Pistons:

B - 53.966~53.969mm
No# - 53.962~53.965mm
C - 53.958~53.961mm

Hi everyone!

Bring this topic back to try to find out which in the biggest piston available for my MC 21.

The manual says there´re three sizes: B - 53.966~53.969mm
No# - 53.962~53.965mm
C - 53.958~53.961mm

I don´t know if this is right, as it´s the first time I´ve seen this system, usually the A piston is always the smallest.

The other strange thing is that I´ve found these pistons in the parts list: B piston 13102-KV3-830
No# piston 13103-KV3-830
D piston 13104-KV3-830

Does anyone know the reason of this difference and/or the real sizes of the pistons in the parts list? I need to fit the biggest ones as my cylinders are close to the wear limit.

Thanks a lot!!!
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Two Stroke Power

If you are replating barrels, send in the pistons and ask for the correct clearance
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Why do things simply when you can complicate them