Originally Posted by
Dave, FormerDairyFarmer
Barry, the 1.00 originally had a pump on the right cam cover, the owner removed the pump and switched out the cam cover. The later 1.00's don't have the pump, it works fine without it.
The pump doesn't affect "running". It is employed to help vent the case since the single throw crank has both pistons traveling in the same direction canceling out any positive/negative pressure pulses.
If one employs some sort of fogger to prevent rust, the pump isn't really of any benefit.