Hello Griff...S.L stated he moved his separtor filter and his still does it.Whats the kit called and do you have a part#?Hank36

I didn't research 500efi's when I was dealing with this issue, but the priming pump from Mercury completely cured my vapor lock issue on 502 MPI. Maybe same fix available for Cool Fuel 500's.

We were out all last weekend on the Ohio, and never experienced it once. It was 103-105 ambient (as you probably know). I never opened the hatch to cool, and didn't have the blowers on for extended periods of time after parking - which was my ritual last year - last year (first year we owned boat), it would vapor lock at anything above 90 degrees (may have been coincidence).

The pump is an easy install, and if you are handy with wrenching, you can do it yourself - essentially plug and play.

Terry

Thanks for the compliment Big Red,tried calling Eddie but I guess he is out of town..Easyrider do you have the part# for the kit you purchased?Hank36

My starboard always did it, 2000 merc 500EFI's. I put a 150$ holy pump in the fuel line before the fuel filter and it never did it again. I wired it to my ignition so when the key was on, it was on, when the key was off, it was off. very easy fix, and same thing merc ended up doing a few yrs later

Part numbers are in this bulletin. However, I believe they've been superseded since this was published. Any Merc dealer should be able to get you the latest level parts.

http://www.offshoreonly.com/forums/g...fuel-pump.html

I scoured the internet looking for best price. I believe I paid about $400 shipped from somewhere in Florida. I can't find the invoice at the moment.

Terry

Hey Boomer was that before the small canister filter thats on the back of the intake?Hank36