Hi, I ran into the stalling problem before. The issue was the rear shift cable on my alpha gen1 drive. If water gets into the cable, it rusts and binds. There is a micro switch on the cable bracket assembly assembly at the engine. It kills the spark for a split second when shifting out of gear. If the cable is old, it can actually bind to he point were it "drags" that switch to the ignition kill position.
I don't think this would explain the bogging down issue, but it certainly could be the cause for the engine dying when you shift from neutral. There is a small arm with a roller on it that presses on the switch. With the engine off, have someone move the shifter from neutral to forward while you watch that switch, it the switch operates while doing this, you may have to replace your rear shift cable. (if water enters the cable sheath, it sometimes makes its way all the way to the carb where it drips onto the engine. Look for signs of this (rust) where the inner cable wire exits the sheath at the engine)
The bogging problem could be the anti-siphon valve where the fuel line connects to the tank. If the gas wasn't treated before it was stored for the season, the check ball could easily gum up and not allow full fuel flow. This would definitely cause a bogging problem (happened to me on a 454 mercruiser, thought it was the fuel pump).
Good luck!
