That model has counter weights riveted to the crankshaft to promote smooth idling. This required trimming the connecting rods for clearance. This robs oil from the top connecting rod. You MUST use a 1 to 16 oil to fuel mixture in order to keep the bronze bushings healthy.
Your Fleetwin has a slick gearcase and is peppy on a light boat. However, a lot depends on the boat and the condition of the propeller.
The neutral depends on the 203116 clutch lever catching the upturned tang on the end of the 202259 clutch drive spring. If it doesn’t catch, it stays in gear. If this tang on the end of the spring is worn it may be bent up a little more. It may just need a little adjustment of the 203239 adjustment nut. This is done by removing the exhaust outlet, two screws, and loosening the 202780 lock nut.
