I bought 2 of the Merc retro-fit kits for my 1999 500 EFI's.
Kit includes an one-way valve to prevent water from draining out of the block when the motor is not running, and an electric fuel pump to be installed prior to the fuel filter.
My mechanic thinks the one-way water valve will cure my vapor-lock problem, and that the second electric fuel pump isn't necessary because all it can do prime the existing fuel pump.
What do you guys think?
Has anyone installed the kit?
Do the post-1999 HP EFI's come with 2 fuel pumps?
Thanks for any help you can offer!