Join Date: Oct 2003
Thanked 95 Times in 95 Posts
Sled: 94 ZR 580
The OEM gaskets are metal and the Winderosa appear to the fiber, or paper type. They are thicker than the OEM gaskets, which will result in lower compression. When you reassemble the top end there will (should) be plenty of oil on the cylinder and rings, so you should have the best seal, a wet seal, in the cylinder, so the compression should be a s high as it ever will be. I don't think you should expect to see any increase in compression reading from a fresh top end to after break in.
It should not be necessary to calibrate your compression tester. Absolute numbers are not important, but what is important is that you use the same gauge and assess the relative readings from cylinder to cylinder and before and after. You can reuse the OEM base gaskets many times, if they are not bent during removal. Use a little bit of sealer on them and you're good to go.