Anyone know what the top end compression should be for a 2000 DS650. It's getting a few years old so I tested mind, was 115 lbs. Appreciate any info.

THE BOMB

That is low....
Did you disable the decompression device on the exaust cam?If not you will get a reading like you got. I have had well over 200psi with a 12:1 piston

I found it was easier to do a leak down test,you should have less then 5%...I typically have seen 1 1/2 % leak down on a good motor. Just make sure you lock the crank at TDC,and do it after the motor was warmed up

jeff

Thanks, didn't think of the decompression valve, is their an easy way to do this. maybe I should skip it and rebuild the motor....was going to do mods to the top end anyhow. Thanks again


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