Yamaha’s 300’s Vapor lock??

[Jupiter Jim]

I have twin 2014 Yamaha’s 300 four stokes on 31 Jupiter CC. Coming back from West End Bahamas we ran about 35 mph. Came through the inlet, into intercostal ran 45-48 mph to the first bridge. Slow down idle speed “no wake zone”, went under the bridge and engines quit. They would crank, but not start. Could this be “vapor lock” ?
Thanks, Jupiter Jim

 

[AllDodge]

Don't think it's vapor lock with both motors just quitting, look at the man overboard kill switch, Battery connection

 

[Jupiter Jim]

Don't think it's vapor lock with both motors just quitting, look at the man overboard kill switch, Battery connection

Thanks for you're input. That was first thing we checked. Actually, it did turn out to be vapor lock. We did have very good batteries, the connections were also secure. We got to the fuel lines under the deck and found fuel bulbs empty. We loosen up the gas caps and primed the bulbs. Engines started right up. Go figure!.
The air temperature was 92° and water temperature in the intercoastal was 89°. We are in south Florida. I remember many years ago when I raced car's on hot day at the track we installed aluminum canisters run aluminum coils through it filled it with ice and connected the fuel to it to keep the gas cooled.
Thanks again ALLDODGE!

 

[AllDodge]

We got to the fuel lines under the deck and found fuel bulbs empty. We loosen up the gas caps and primed the bulbs.

Good to hear your running but that's not vapor lock, it's Tank vent restriction or clogged.

If vent line to tank clogs or badly restricted, the fuel pump will draw a vacuum on the tank. Opening up the gas cap lets air back into the tank so pumps can draw fuel. Check the tank vent line

 

[fitz73222]

I would be looking at what is common between both engines since they both shut down at the same time.

 

[Jupiter Jim]

Good to hear your running but that's not vapor lock, it's Tank vent restriction or clogged.

If vent line to tank clogs or badly restricted, the fuel pump will draw a vacuum on the tank. Opening up the gas cap lets air back into the tank so pumps can draw fuel. Check the tank vent line

Thanks for the tip, will do.