Hyway piston in 372xp

[slim reaper]

Hi, I've got a 372 xp, not x-torq on the bench that was low on compression, muffler off and slight scoring of piston.

Performed vac + pressure test which was ok so stripped down.

Cylinder is good with what I think is the original piston but ring gap was 1.8mm which accounts for the low compression. I advised my Nephew to get a Golf piston  but was proving elusive so he's brought a Hyway.

I only ever rebuilt with pistons that have a single ring so asking if there are any issues with two ring pistons before I stick it in?

Thanks

 

[spudulike]

It shouldn't cause any issues and may give you a little more compression on a slightly damaged cylinder.

I have done tests on a good cylinder and removing the lower ring caused no change to the compression reading - I guess you could just leave out the lower ring if you wanted less friction from the rings to bore!

 

[Crocky]

if you're using a hyway piston buy OEM wrist pin circlips and either caber or OEM piston rings. I've seen hyway circlips and rings snap and wreck saws. if its meant to have two rings leave them in. taking one out will not give you any benefits and can make the piston slightly more unstable as the top ring sits slightly higher than it would if there was only one.