I just ran a compression test on my ebay engine. I am at 6,000 ft. elevation. The manual says the pressure should be 3,040 to 2,200 kpa (441 to 319 psi). My air pressure here is only 80 percent of sea level, so I was looking for 353 to 255 psi.

For cylinders 1,2,3,4 I got 300, 305, 295, 295. My gauge only goes to 300 psi, or I would have tried putting oil in the cylinder and retesting.

I tested the glow plugs too, and I had a bad one as I suspected from the smoke.

The compression ratio is 21:1. 21 times my air pressure of 11.8 psi should only be 249 psi here, or only 309 psi at sea level. I don't understand how it would be as high as 441 psi. Can anyone tell me what numbers they have gotten?

Thanks!