There are 2 powerpacks on the motor.-----Look into the control box at the helm.-----Might find a gray wire there.-----The factory tachometer operates with alternator pulses.
Are you sure that is the correct distributor cap for your motor.-----Perhaps another case of --" they look the same"----But are not the same.----Put the old cap on and test run ?
There have been issues with crankcase sealing rings.----Results in low crankcase compression.----Post the actual cylinder compression values.-----That may offer a clue.---Yes, you can put a PRESSURE gauge on the port to see what happens.----The fuel pump does NOT run on vacuum !
The fuel pump runs with the PRESSURE from crankcase compression.----That is not the same as compression in the cylinder !-----There may be an issue with crankcase compression and fuel pump does not work !-----Mix the fuel at 50:1 in the portable tank.----Have your assistant operate the manual...
Friends of mine had one of these motors on a 17' deep V boat.----Skied many miles behind it.----Used to pull 2 skiers out of the water with slalom skis.----A real powerhouse.----Take starter apart for inspection.-----See what it needs.