I am having trouble getting the timing set on my rebuild.If I use the timing marks it wont idle without turning up the idle speed on the carb which in turn opens the throttle enough to activeate the ported vacuum outlet advancing the timing when the vacuum hose is reattached.If I advance the timing to 55 BTDC it will run fairly good but still not right.I would like to figure out as close as possible how far out the damper is.I have a tape which shows lots of timing marks,If I knew how far out the damper is I could compensate when using the timing light.If I had known the damper was innacurate I would have replced it before assembling the motor.