Starting Problems only seem to happen in the summer.

[ctown]

I have the same problem each summer. I can't seem to get one or both of my engines started in my 2000 SeaRay 270DA.
I called a Tech out a last year and said he had to "Hot Wire" to fuel pumps to get the gas to flow. Something about as the fumes in the tank expand in the summer heat, and the fuel being heavier". I'll assume this is something akin to "Vapor Lock". Does anyone else have this type of problem with starting engines. My boat has 2x191HP Mercrurisers 4.3L
Any information would be greatly appreciated.
Thanks /forums/images/graemlins/confused.gif

 

[alan006]

If my memory is correct, the earlier 4.3 had a mechanical fuel pump and the later have an electrical fuel pump. I don't know why they changed it because the mechanical pump seemed to give me a lot less trouble. If I hadn't used the boat for a while I used to find the electrical pump struggled to prime the carbs. Once it started it was fine.

 

[alan006]

The vapour lock idea seems odd. Your fuel tank must be vented and this will equalise pressure for the tank with the atmosphere.
The fact that he hot wired the fuel pumps does support the idea that the problem is priming the fuel system. One solution I have seen ( I not sure if it is safe though) was to fit a priming bulb ( as per outboard fuel lines) in the fuel line and you could hand prime the fuel system.

 

[brianrunyard]

"Hot wiring" the fuel pumps, has nothing to do with a vapour lock, it just runs the pumps.
It's probably that the system need a bit of priming.
I've got a priming bulb in the fuel line, so I can fill the carbs before turning the key, always starts instantly.