New piston old rings?

[cuinrearview]

If the ring pins aren’t 100% on the money, you wont see the benefit of keeping the old rings.

If the popup is AM, It’s likely they are a bit off.

Personally, I’d add a new top caber and retain the old lower ring. Better upper ring tension and the benefit of a looser/less drag lower ring with the same heat dispersion.

Two rings?

 

[drf255]

Two rings?

Can run a top ring only. I do on some models because of where the factory put the bottom pin.

MS361 is a fine example. It’s on the edge of the ex port and one can’t widen the port much without the chance for disaster.