Really not worth a lot, depending on condition. Especially since it is a small HP, I would start with low initial bid to not scare people away. Too many people go with $99 starting bids and they get no action. You can always set a low reserve to get the minimum you are willing to take. Keep in mind that somewhere around $50 is the estimated value, according to Peter Hunn's book. But, those are rough estimates. A lot of factors influence selling price.
Another option is to place a free "for sale" ad on AOMCI.org. No selling fees and someone who likely knows about motors might buy it. Best offer approach works well through that venue.