I owned a 1953/4 Superfastwin 15hp. It was one of my favorite motors, very depenable, smoooth running & very quality bilt. Go over your motor, compression, completeness, reseal gearcase & tune up. If compression is good, mix oil 5 gallons of fuel to a quart of premix oil. Always had great memories with my Fastwin. Bought mine from a bait shop 35 years ago for 250, needed a tune up & gearcase reseal, Wiah I still had it.