AJS & Matchless Owners Club

Posted: **Fri Oct 05, 2012 8:33 pm**

Anyone have an idea what sort of lbs per square inch pressure I should be getting when I do a compression test on my 1958 600 twin when warm. Thanks Ray Woolford

Posted: **Fri Oct 05, 2012 8:58 pm**

Don't know the pressure for a 600 twin; but it's as important that the pressures on each cylinder are within 5-10 psi of each other. Anything more than this and you may have a problem on the lower pressure cylinder.
Cheers,
Phil

Posted: **Sat Oct 06, 2012 2:30 pm**

On my standard compression G12 650 with warm engine and fully open throttle 130psi. Shouldn't think its much different on the 600.