The Stovebolt Site Forums The Shop Area Engine Shop Turning over too slow... Maybe?

The max voltage of the 6 volt is 7.5. The engine timing may be far advanced. If the ignition fires when the piston is deep into the stroke, the pressure is high. This will cause the starter to drag. Set the timing at TDC. You can set the spec timing after you get the engine running. You may be 'hearing' pre-ignition.