Posted by Todd Wilson on Monday, February 06, 2006 at 12:07PM :
In Reply to: Flathead Valve Noise - Time to adjust Valves? posted by John M on Saturday, February 04, 2006 at 8:56AM :
Sounds like detonation. Either from carbon build up or poor/old gas or timing. I've seen V8's do it with wore timing chains.
Get some seafoam and run thru the carb per directions on the can and then run it in your fuel for a few weeks.
Todd