HI bax, my OS vz has been running really good. tuning has been super easy, temps usually between 220 and 250, strong idle.

the last 2 weeks racing I've been chasing the tune, seems to be running hotter and top end feels flat. like 2/3 down a 150 foot straight(dirt) it stop going faster.

I was just commenting that the problem with these engines loosing compression at 2 gallons is not going to happen to me. I have never run this engine without being preheated and break in was run at 200 degrees. not higher and not lower.

when I came off the track tonight it still had a strong idle/was 265 degrees but I couldn't make the tripple jump.


with the glow plug out and the engine cooled off I have no pinch at all. it almost will spin around a few times on it's own with your finger.


Now here is my question.

I have another sleeve that was set up ( pinched)to run the old RZ piston.
I know there is a difference because the VZ has "rings" around it and the RZ doesn't.

DO I try this experiment? or send the engine back to OS ?

IF I send it back what ( in your opinion) will they do for me?