Is it a given that both cylinders on a sled have to be bored out? I had 1 cylinder overheat and sctratched the liner pretty well. I think I know what the correct answer is but was wondering if anyone ever tried doing just one...thanks...Jim 340cc F/C

I would think for balance (weight and compression) you would need to do both.

Was this your answer?

yep, I do think if you want to do it right both should be done...thanks

Depends. What sled is this for? Is it a plated cylinder or an iron sleeve? I believe all cat motors use nikasil plated cylinders. These cylinders cannot be bored, they have to be replated if the plating is damaged beyond repair. Often the cylinder can be washed and resurfaced without having to be replaced. A replated cylinder will have the original spec bore and only the one piston will need to be replaced. If there are plenty of miles on the motor I tend replace both pistons at the same time so I have a completely fresh top end. The undamaged cylinder will need to be resurfaced to have a fresh crosshatch for the new rings to seat against.

replating one cylinder is what I would do. millenium technologies did mine with fast turn around and really took care of me,,,, sled runs like a beast once again,,,,