Hi everyone,

I have pulled the pistons and barrels off a newly acquired MC21 SE to inspect and decide if they need replaced.
Trouble is, I don't really know what I'm looking for.

The bike was a bit tatty and has been a track bike at some point (assumption based on lock-wiring) so I was concerned
it may have been trashed and may have suffered as a result.

It did start a run without any problems prior to me pulling it apart, but just wondered if the attached pictures tell us anything interesting.



Any advice greatly appreciated.

Al.
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Cheers....

Al

Bikes:
GPZ900
NC30
NSR250SE
RGV250 vj22

Hi Al
The pistons actually look quite good, much better than mine were anyway. My guess would be that they have not done a huge amount of mileage.
It's difficult to tell from your pics the condition of the bores but, again, they look ok.
Carefully remove the rings (making sure you remeber which pistons they came from and remeber there is a top and bottom ring. Do a gap test in the bore (see the workshop section on this site) and if the clearance is within spec then refit, or replace with new.
Make sure that piston ring grooves are completely free from crap.

I'm not an NSR expert (might be when I've finished building mine) but this is just common two stroke knowledge.

Good luck.

Mike
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I don't mind dying...I just don't want to be there when it happens!

Hobbit210 wrote:Hi Al
......... remember there is a top and bottom ring. .........

Mike

AND the top ring has an upper and lower side.
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Poul
"If Life Gets Boring, Risk It!"
MC21SE, KISS box
MC21SP, HRC box, racing loom

pbekkerh wrote:

Hobbit210 wrote:Hi Al
......... remember there is a top and bottom ring. .........

Mike

AND the top ring has an upper and lower side.

Absolutely.
_________________
I don't mind dying...I just don't want to be there when it happens!