NSR250 Piston & Rings

**Wed May 04, 2011 7:09 pm » Post: #1 » Download Post**

Hi All. I am having problems with pistons and rings on an NSR 250 (MC21) I am bebuilding. More specifically, pistons (pn 13102-KV3-830)and rings (pn 13010-KV3-305) I purchased don't seem correct for the rebuild. The pistons seem to require a flat/rail ring in the bottom groove and a serpentine ring in the top groove. The rings I received (as numbered above) appear to both be flat/rail style rings and do not fit into the top groove. Have you run into this before and if so, where can I get the correct rings?
Mark
_________________
What's the latest?

**Wed May 04, 2011 7:16 pm » Post: #2 » Download Post**

I beleive the correct ring set part # is:

131A2-KV3-701

**Wed May 04, 2011 9:34 pm » Post: #3 » Download Post**

Thank you. Does my piston/ring non-fitment make sense based on the part numbers I posted? Are you familiar with the piston and does it infact have 2 different style of ring grooves?
Mark

**Thu May 05, 2011 2:53 am » Post: #4 » Download Post**

By the way, can I buy these rings anywhere?
Mark
_________________
What's the latest?

**Thu May 05, 2011 7:58 am » Post: #5 » Download Post**

All normal NSR pistons have 2 different rings, the pistons/rings from a 1988 NSR250 mc18 and a 1995 NSR250 mc28 are totally compatible.

I'm unsure of the prices and availabilty in the states but looking at prices in the UK from Honda it's far cheaper to order pistons and rings from Tyga even if you use UPS for delivery, and you'll get the right bits;

2 x pistons and rings, UPS'd from Tyga £113
2 x pistons and rings, from David Silver £207
2 x pistons and rings, from CMSNL £220
Honda UK are even more expensive.
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread

**Thu May 05, 2011 12:41 pm » Post: #6 » Download Post**

For US availability, you wont find these at your local Honda dealer.

Try www.redline-ci.com, Craig can get them. or check with TYGA, or other vendor listed on the forums ads.

The piston seemed to be the proper part # from the parts manual, the rings, not sure where that part number came from?

**Thu May 05, 2011 1:03 pm » Post: #7 » Download Post**

This is very helpful. I am happy to know that it is normal for the proper piston to use 2 different style of rings. I will call/email Tyga. Are you at all familiar with the RC exhaust valves? I have a different post here trying to figure out a clearence problem...
Mark