[XLsior]

Greetings,

So the New 67mm Piston and Rings came in the post yesterday.

Using a 10mm thick float glass panel for a flat surface and taping down some wet'n'dry 240/400 grit sand paper I cleaned up the cylinder mating surface just enough with 400 grit as keeping the stoke distance without interference here is important.

Where you can take off some material is the Head to increase the compression. I didn't go to hard on the first pass. I have since purchased a sheet of 240grit to take away a little more surface material. then finish with 400 grit.

the process isn't complicated. Even pressure with an orbital rotation action. turning the part 90* every so often.

NOTE: the CG250 head lower exhaust stud has to be removed for complete surface contact.

As for the Piston rings, All seems in order when compared to the shagged used parts.
If anyone can impart a knowledge nugget regarding the ring order/orientation (I have taken photo showing Rings marked with D/DY) From what I recall the marking a faced up but not sure which is the top ring.

Also any ideas on ring gaps?

I'll take some more pics of the second Head shave and probably do another pool noodle cylinder hone pass with the 400 grit.

Cheers for checking my project thread.