Why is the timing mark out by a mile

[black as]

Guys
I have a 350 chev with a 4 barrel Rochester, the problem I have is Ive set the dwell to specification and set the timing to 9 deg B.T.D.C. and the motor wont throttle up, once I retard the timing to about 20 deg B.T.D.C. off the scale lets say, it runs O.K. Any idea what the problem may be

[delcowizzid]

that way would be advancing the timing BTDC is advance towards/after TDC is retarded.maybe the mark has moved spun balancer

[black as]

that way would be advancing the timing BTDC is advance towards/after TDC is retarded.maybe the mark has moved spun balancer

How can you tell if youve spun the balancer ?

Also If the dizzy was out 1 or 2 teeth would that give you an incorrect reading ?

[delcowizzid]

easiest way snap all the porcilain off a spark plug and screw a bolt down it the screw it in and turn the engine by hand untill it touches the bolt and stops moving mark the balancer with twink at the tdc mark now turn the engine backwards till it hits the bolt again and mark again at the tdc mark now if the timing mark on the pulley isnt in the middle of the 2 new marks its spun

[black as]

easiest way snap all the porcilain off a spark plug and screw a bolt down it the screw it in and turn the engine by hand untill it touches the bolt and stops moving mark the balancer with twink at the tdc mark now turn the engine backwards till it hits the bolt again and mark again at the tdc mark now if the timing mark on the pulley isnt in the middle of the 2 new marks its spun

Cool, thanks mate I will give that a try

[delcowizzid]

there is a pick of the "greenfoam special" tool on here that he made just like above will be in his build thread if you need to see how long to make one but if it turns right round get a longer bolt if you need a shorter ladder just slide the two lock tabs in and LOL i hate that add

[BowTie]

Can do similiar, though not as accurate test with 1/4" socket extension bar or long screwdriver just by removing pug and inserting the tool to rest on top of the piston and hold while turning over motor by hand. TDC is obvious.