My 742B moves a lot of air. I can't see an electric fan moving more than what is already being pushed through in my own application and I am pretty sure it has not been a part down to the flywheel. Is the flywheel and fan 2 separate things if you look it up in a parts catalog{or online}? Just a thought, but could it be possible somebody left a portion of it out during a previous service.FWIW, the fan on my 742 seems less than adequate as well. I think a decent sized electric fan would have been better, but recall that electrics were not as popular back when these machines were made as they are today.