NH125 Piston replacement

[Mileslord]

I am have ordered a GT250 X7 Mitaka Piston from PJ Motorcycle engineers. From what I have read and researched this should be a viable replacement piston. I will post more when I receive it.
-Miles

[donny]

Hi that will be interesting, the list of scooters you know what you are doing. Nice rides

[tyler vr]

Any info about a replacement piston nh125 would be great, keep us updated.

[Florida Antique]

Tyler,
There is a guy in England that has replacement oversize pistons for NH 125 engines, He advertises them on Ebay. From what I understand they are Taiwanese made and not bad quality but the rings are a little soft. The piston in my bike was replaced with a Weisco piston for a CR125. Because the ring stops are in the wrong location they had to send the piston and cylinder out and have the piston re-indexed. From what I understand, this is a common practice in outboard motor racing. Once the piston was re-indexed and installed and broke in properly it ran fine. That would probably be a viable alternative to a factory piston which is NLA.

[tyler vr]

Tyler,
There is a guy in England that has replacement oversize pistons for NH 125 engines, He advertises them on Ebay. From what I understand they are Taiwanese made and not bad quality but the rings are a little soft. The piston in my bike was replaced with a Weisco piston for a CR125. Because the ring stops are in the wrong location they had to send the piston and cylinder out and have the piston re-indexed. From what I understand, this is a common practice in outboard motor racing. Once the piston was re-indexed and installed and broke in properly it ran fine. That would probably be a viable alternative to a factory piston which is NLA.

Good info, thanks. I remember reading something on the forum about changing the ring stop location on a replacement nh125 piston. I hope Mileslord follows up about fitting this GT250 X7 Mitaka Piston to the nh125, hope it works out.

[Mileslord]

I got the piston today from PJ Motorcycle Engineers.

the ring pins are in the correct spot





Now off to Bill Bune http://billbune.com/ for the machine work

[tyler vr]

Nice!

Is the replacement piston oversized?

[Mileslord]

Yes, it is a 56mm 2.0 oversize piston.
have not gotten to the machine shop yet, tranny went out on my van so that has been the object of my attention lately.

[ghalperin]

Do you happen to have a part number and application for the 56mm piston?

[flybd5_juan]

Do you happen to have a part number and application for the 56mm piston?

The Peugeot SR and SV 125 both use the Honda engines. Barikit has the correct size piston for the 125, part number P-264. 55mm.

[ErikBuzzard]

Yes, it is a 56mm 2.0 oversize piston.
have not gotten to the machine shop yet, tranny went out on my van so that has been the object of my attention lately.

Any word on this? Did it work? I just seized my aero. Looking into more options than the 140 replacement piston

[ghalperin]

I just ordered one on eBay from England. My machine shop had to trim the skirts, but it’ll work.

Suzuki GT250 GT 250 X7 M/A 56.00mm Bore Piston Kit Also RG250 GT380 (OVERSIZE)
https://www.ebay.com/itm/Suzuki-GT250- ... 2749.l2649

[ErikBuzzard]

I just ordered one on eBay from England. My machine shop had to trim the skirts, but it’ll work.

Suzuki GT250 GT 250 X7 M/A 56.00mm Bore Piston Kit Also RG250 GT380 (OVERSIZE)
https://www.ebay.com/itm/Suzuki-GT250- ... 2749.l2649

How well does it run? Have you ran into any issues?

[ErikBuzzard]

I ordered the same piston. Just got it today! Gonna take the cylinder to the machine shop soon! Christmas is around the corner so my money is tied up lol. I have a polini scooter pipe made for piaggio that I'm gonna hack and weld. I want to get a new carburetor any suggestions?!