500 EFI upper rebuild?

[stevewy]

Thanks for all of the responses to my questions in the other threads. Now, the question for the day; when should the 500 EFI have an overhaul -- and what should be done (complete? Valves/springs?)

The previous owner took great care of her. The motor has pretty much been babied, certainly not ran hard. I have about 375 hours. No problems. I've been told that @400hours mercruiser recommends service overhaul. I probably won't do anything this season, but can do what's needed at seasons end. I'll probably end the year with about 450 hours

[Ratickle]

Nothing in their manual on the 500efi about rebuild.

http://www.mercuryracing.com/_media/pdf/manuals/sterndrives/2002/500%20EFI%20Bravo%20XR_XZ_III%2090-840175021%20601.pdf

[endeavor1]

Efi not so much, carb is a must. I'd leak them down and see where you stand. 10% differential and I'd be looking at refreshing the motors