NX250 MD25 (239 ccm) piston ring set

[doyar]

Hallo everybody,
probably in a moment I will have a full set of cylinder rings for the MD25 version reproduced (copied). From what I know, OEM ones can't be bought anymore. So if there is anybody interested in getting such a set for themselves - please contact me, we can join forces. I don't know yet for sure whether it will work and what the cost will be. I know that the same workshop reproduced a set of rings for my friend's old Yamaha XTZ 660 some time ago and it costed him 300 zlotys (~ 70 Eur). They already have my cylinder, piston, old rings and a page 10-5 of the Manual I will probably know the costs in the next few days. Cheers!

[doyar]

So: I do have a set of reproduced piston rings for my MD25. Unfortunetely it was not possible to find the oil rings 0,2 mm thin so they are 0,25 mm thick. Apart from this everything else seams to be OK, the 'minute' one is chrommed and chamfered. The upper chink in my piston was also widened by some fraction of a mm, as it was 'overclapped' and the ring it acomodates was made accordingly. All this costed me ~35 EUR, 2 km from home I have to believe the guys who made it that it is all fine, as they are dealing with this kind of stuff for decades. Well, the next few weeks would show wherher to laugh or cry...
Cheers.
P.S.
"Prima" is not where I took the rings from, though I suspect they could give some base for that I get.

[MariaS]

And? How are they running?

I am stuck in Central America and need a new piston ring set, same size...

[scrambler]

And? How are they running?

I am stuck in Central America and need a new piston ring set, same size...

Piston rings for the 239cc NX250 are said to be available here https://www.scheuerlein-motorentechnik. ... ndardmass# - but I haven't tried it yet. Actually the piston rings don't wear out on the NX250 - what happened? Maybe I could help out with spare parts.

[MariaS]

Thanks a million! So hard to find! My Google searches did not come up with anything! I ordered them, just to have them, even if I don't need them yet. Actually, I am not sure what happened? Good to know they don't normally wear out. I have a lack of power going on and may have misdiagnosed the problem. Found tight intake valve clearances today, so that may be the culprit after all.

I do have high oil consumption, but no idea why (no blue smoke, no oil on spark plug). So that is a mystery I still have to solve. So I am not ruling piston rings out yet - see how the compression test comes out, once I've adjusted the shims...

Bad carbon fouling on the spark plug, so taking the carburetor apart for a clean and inspection this week....