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?

We don't have any experience running O.S. engines in other than their stock configuration. We can't comment on using the modified parts.

If you believe your engine's problem iss due to how it was made, then it needs to go to the service center for warranty consideration.