7.4 MPI fuel system
 

Hi, I'm new to the forum. Running a 2000, 7.4 MPI, B-III. After reading a few threads, can see I'm not the only one having 'hot restart' problems with this engine due to vapor lock. I've read the merc bulletins on the cool fuel system that describe the problem exactly as I've experienced.
I'm considering retrofitting with an entire replacement fuel system and would like to ask if anyone has done this. Also would like to hear discussion on exactly where the failure point is.

If your boat is not already equipped with it get a "backflow valve" for your cooling hose feeding the engine. This valve installs inline between the coolfuel unit and the thermostat housing and stops hot water from drawing back and heating up the fuel pump. This is the first step, next is a "fuel boost pump" if your engine is not already equipped with it. Your merc dealer will know about these items, or at least he should! These 2 things cured my boat of the hot restart problem without rebuilding the fuel system.

Thanks for the input Daytona. Don't presently have them installed. I'll look into adding them.

We have installed many of the check valves and only a few of the boost pump kits so try the valve first cause the boost pump kit is a little pricy $$$.