I had a pro-line starter last year, Tilton style. The best i can describe is the starter makes a Zinging noise when ignition is turned. If i keep taping it multiple times it finally engages to turn motor. I tried shimming it last year with up to 8 shims which is about 3/8" down. Still had the problems end of last last year. So i figured i would try a different starter after talking to Mike at Prime. I bought a new one from Prime Marine to see if if that changes anything. I installed it today with no shims, still same problem. I can tap it until motor engages and it will turn the motor over eventually, but after the motor turns over a few revolutions, it stops turning over the motor and starts that zinging again with no engagement. Could it need more shimming down? Any help would be appreciated??? At wits end!!!