I know there has been a lot of talk on here about this problem. Mine is a mild build 500hp 96 502mpi. Twice today I had vapor lock that would shut down the engine. Both were after a 15 minute slow no wake run through the channel.

I'd really like to remedy the problem, but don't know if there is anything i can do. It would be real nice to just get the cool fuel system, but don't know if that's possible.

One idea I had was to reroute the fuel line from the front of the motor and either route it to the back of the motor, or up further using new AN aluminum lines. Don't know if it would work or not............... It's pretty embarrasing to get up on plane, and then have it quit and come back down. I'm sure glad i have the back exhuast flappers as well as the internal rubber flappers as two lines of defense to keep the water out of my cylinders when that happens.........

You can take the fuel line return and remove it from the filter, buy 2 fuel fill adapters the size of the fill hose and return the back that way into the tanks or if you have another pick-up on the tank return there. You could also use the vent line if you can get close enought to the fuel tank.

Anyone else come up with a fix?

http://midwestboatparty.com/forum/ar...hp/t-5363.html

Once its running it should not vapor lock. Vapor lock generally happens after running the boat and turning it off. The heat in the engine compartment evaporates the fuel in the lines.

mine is doing it after a 15-20 minute slow no wake. Engine bay is getting heat soaked. blower on or not........

The sure fire way to fix it is to return the fuel to the tank. This will absolutely stop the vapor locking.
Eddie

Can you elaborate on this?

I was also thinking of abandoning the steel fuel line routed in front of the motor, and making up an rubber fuel hose with fittings and routing away from the motor. I would think the change from steel to rubber in itself would help the fuel temps in the line.

You cannot use rubber fuel line for a marine engine. Against USCG rules.