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60mil
08-19-2003, 09:06 PM
i have digital 6 plus,chevy pro billet dist,blaster coil,and 8.5 wires. my question is i originally set the initial advance to 12 deg. with blue & silver springs and blue stop bushing. approx 21 deg xtra at 2500 rpm. the motor ran fine for a couple of months until it started to run a little rough, no backfires thru either carb or xhaust. i checked the timing and it was close to 48 deg initial advance. when i revved the motor to 2500 the advance only went to 54 deg. that's 6 deg only when is should of got 21 deg. i loosened the dist to reset the initial advance and can't come close, i can get it to 25 deg and any farther the motor wants to die. when i rev it a this setting it is very slow throttle response. where did this xtra advance come from and why do i only get 6 deg of centrifugal advance when i should get 21?

msdtech1
08-19-2003, 09:14 PM
If your harmonic balancer is the type that has a rubber ring between the outer and inner hub then you need to check to make sure the outer ring has not rotated on the inner ring. Bring the engines number 1 piston to Top Dead Center on the compression stroke and verify the the TDC mark is still at zero. I suspect that is what has happened.

MSD Tech1

60mil
08-22-2003, 01:46 PM
thanks for the help, you saved me hours of time hunting for the problem,the harmonic balancer was the problem. but i wish it was the separated rubber. the balancer spun on the crank cratering the keyway and breaking the balancer bolt inside the crank.

msdtech1
08-22-2003, 02:28 PM
I am very sorry to here that. That was the worst scenario that could of occurred for you. Sounds like you have your work cut out for you to get that one fixed.

MSD Tech1