7.4 Mag MPI no start when hot
 

Have a 2000 Baja 342 Boss
twin Mercury 7.4 Mag MPI
At all speeds, the boat runs fantastic
When I shut the boat down or any length of time, the starboard motor will not start ?
It may start an hour later it may start a day later
I already changed the cap, rotor and distributor ignition module.
I have a new distributor pick up sensor, but I’m avoiding putting that in because I would have to pull the distributor
At this point, I’m not sure if it’s ignition or fuel at this point
Kind of thinking a vapor lock issue but just not sure
any assistance would be greatly appreciated

VST cool fuel system causing vapor lock possibly.

that pump should be right between the two engines the hottest part of the bilge, vent by raising the hatch while at rest and see if that helps

are you talking starts, stumbles and dies? Thats vapor lock. Cranks but wont even trry to fire? I would think more toward ignition .

Have you checked for spark? Pull a plug wire and see if you're getting any spark. Plenty of methods that won't short out your coil...or light you up!

Unless you get a direction of problem, you're dead in the water.

2000 year engines are Cool Fuel.

Most likely vapor lock. Pretty common issue. Does it turn over, sputter and then stall??? If you cycle the key several times to activate the fuel pumps and keep trying to start it in 2-3 second bursts, it should fire after several tries.

To help mitigate the issue:
Do not run Ethanol fuel. Run your blowers for 15 mins and crack your engine hatch after shutting the engines off.