1st oversize piston set required. 66.5mm.

[Gibsones295turbo]

Compression around 70Psi, I've waited 5 weeks for a rebore & am told i need 1st oversize which is 66.5mm.
Ive looked everywhere and just cant source them.
Didnt fancy going for a big bore kit as apparently getting a head gasket is troublesome too & i didnt fancy altering fuel pressure and any other odds n sods.
I've just spent 1k on having the turbo refurbished & now want the bike running.
From the south east of the U.K.

[JezZedexE1]

Do you want oversize pistons, oversize piston rings or both?

Screenshot 2026-05-30 105738.jpg (97.07 KiB) Viewed 822 times

Try Z-Power or CMSNL.

[Gibsones295turbo]

Cheers Jez, i have tried Z power but they say No.
I am after the complete set of 4 pistons, gudgeon pins, circlips and the complete set of rings.
All at 66.5mm as its due to be rebored.

[JezZedexE1]

The pistons, as far as I know, are unique to the Turbo. No other models show up in a search on CMSNL. That is going to be your biggest issue.

For the rings, etc, try searching for other/newer models that use the same components with the same or superseded p/n.

OR

11005-1306
https://www.cmsnl.com/en-gb/products/cy ... 11005-1306
This is the cylinder block and is used on numerous other models. Maybe you can source a good second-hand/NOS one.

[Gibsones295turbo]

Cheers mate.
Quite frustrating.
I've had my engine spread all over my workshop for nearly 4 months now. I had the turbo completely overhauled & its just sitting there looking at me..
Looks like i will have to just re ring it , hone it out and hope for the best.
Or spend loads of money on a big bore kit.

[Kawadoodle]

How about getting new rings, pins and circlips and get a specialist machine shop to manufacture and i stall std size liners.

[Gibsones295turbo]

I managed to source another cylinder block which only needed " hone" so i got that sorted sorted last week & now waiting for IMD pistons to get back to me with a set of rings.
I will probably use my standard pistons as they seem ok.
Sourcing turbo pistons at 1st oversize is more difficult than cycling to the moon. ( with a puncture).

[JezZedexE1]

Good news there. Hope it all works out and you get up and running.

[Gibsones295turbo]