Fuel Vapor Lock ?

[TheMayor]

Hey guys looking for some help based on your experiences. I have a 21-foot Cheyenne Day Cruiser with a covered engine box running a Harman Marine 330 HP 454 and Berk JG pump. I was out at the lake this weekend and after running for 30 to 40 minutes I powered off to let the kids play in the water and setup a skier. When I went to fire the motor after sitting for 15 minutes it would not start, the motor turned over fine but would not fire. After being towed in and trailing the boat it fired on the first turn. Question is, has anyone experienced fuel vapor lock on a boat. I have seen it before on large street motors with big cams when there are at idle for a long time. I am running a mechanical fuel pump with 3/8 rubber fuel line to the carb, Edelbrock #1410 750 CFM. Any thoughts or suggestions would be appreciated. :confused:

[Danhercules]

Sounds like it to me. I have never heard of it on a boat before. I guess it could get that hot. Make sure fuel lines are away from anything warm.

[Moneypitt]

I don't know why your boat wouldn't start, but vapor lock doesn't act like that. Vapor lock is a condition that heats the fuel in the fuel line, creating vapor that has more pressure at that point than the pump can pull fuel through. This condition usually occurs during a high demand on the fuel system, and re starting a warm engine isn't really a high demand situation. There should've been fuel in the bowls, plenty enough to start and idle, even if the line was "vapor locked". It is possible you percolated the fuel in the bowls, which causes flooding, and possibly wet plugs, but since it re started easily later, that doesn't ring true either. If it happens again, and it probably will, 1st check for coil output while cranking. If you have spark, then look in the carb,(KEY OFF) and see if you have any fuel squirting from accelerator pump. These 2 things will tell it all. All you need is fuel and spark.........trouble shoot it from there.......Moneypitt

[TheMayor]

Moneypitt – Thanks for the feedback, I did check the ignition and was getting spark. I also talked with Greg from GS Marine and he said the same thing, thinks the floats maybe off or getting stuck and it is flooding the motor.