- Joined
- Oct 27, 2023
- Messages
- 20

Can anyone tell me what the compression reading should be roughly on a reconditioned 600cc Dominator engine after bedding in...? Cheers.
I compared both engines cold for the comparison.I would estimate that you might need 8:1 compression ratio to see over 180 psi on a compression test. If your inlet valve closes very early or very late, then my estimate is wrong.
Cold compression tests don’t mean much, but 80 psi is very low. Run the engine for a while and repeat the compression test.
180 would be higher than expected, but again, there's a lot of factors, like how much oil you added.Checked dry and compression was 100 on one, 80 on the other (dry test). Checked our other 600 and it was 165 on both dry, 180+ when we added oil. Would this be normal for the 2nd engine or would hi compression pistons be needed to achieve these figures?