Indmar Marine Drive Belt – Ford Supercharged | 95 Amp / 170 Amp Alternator | Part #725902 Keep your supercharged Ford Indmar engine’s accessories turning with this genuine Indmar drive belt, specified for supercharged Ford engines running a 95 amp or 170 amp alternator. A worn or glazed belt can slip under load, leading to poor charging, overheating and a flat battery on the water.