Hello all, I have a 1993 20ft Larson 200SEI with a Mercruiser MCM 5.7L V8/350 Thunderbolt IV and Alpha I stern drive. I decided to do a tune-up; oil change/Filter, Gas filter, plugs, wires, rotor and cap. Before all this my boat started every shoot, after the tune-up it started once, idled for several minutes then died It turns over just will not start, battery is good, safety switch is good, I have no spark at the plugs and no spark at the distributor and coil. I checked the fuses all is good....I'm lost and frustated...thank you for any help..