View single post by Jensen Healey
 Posted: 08-19-2014 07:24 pm
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Jensen Healey

Joined: 03-11-2005
Location: San Anselmo, California USA
Posts: 983
I have several heads with burnt exhaust valves. I suspect the engines didn't have proper maintenance since adjusting valves on the 907 is so difficult and time consuming.

The stock pistons are 8.5:1 and the cams have a lot of overlap, so don't expect compression readings over 130psi.

A leak down test should help identify the issue, unless your engine has multiple problems.

When I got my car the leak down showed air leaking past the rings blowing out the breather tube. Also air leaking through the exhaust valves into the exhaust system. I did a total rebuild.