Is there really that much difference when it comes to resale on a boat if it has a factory Merc Racing 500 EFI VS a custom built motor with paperwork and high end parts? I melted a piston in my 500 and contemplating whether to rebuild mine or buy a different motor with only dyno time. Personally, I would rather have the custom build cause likely its as good or better built than the Merc Racing motor but I know alot of guys dont see it that way.

I think the value people see in them is not the sum of the parts, but the company behind the parts. Not at all saying that Mercury has good customer service, or that there is anything remotely special inside of a 500EFI (there isn't).... but Mercury being a large company has manuals, specs procedures, parts, accessories, etc that a custom build motor doesn't. For your deep technical questions specific to your "custom" motor you're often at the mercy of one man. I'm not saying this is a good or bad thing, but I think it takes a lot of "doubt" out of buyers minds.

it depends on who the other builder is, if you're talking chief, zul, sterling,eikert or other top notch guys with a long track record of excellence it makes a big difference vs joeblows performance engines that builds circle track car engines 5 days a week and squeezes in a boat engine here and there...

btw rebuilding yours would be much cheaper than buying a complete engine. you only need some machine work, bearings, pistons rings gaskets etc, your not buying heads, blocks, cranks etc all the high dollar stuff....

understand what your saying but there is no warranty on any 500EFI anymore and I doubt anyone sends theirs back to Mercury for a rebuild at their ridiculous prices. the motor I'm looking at is built with a gen 6 502 block and I will be running my CMI headers/exhaust

I'm not insinuating that Mercury is the resource for rebuilds and maintenance... but if you need your rod bolt torque spec... the size fastener that holds the valve covers on, etc, that's documented by Mercury somewhere... available in a manual, etc.

true. I get what your saying

To me it is the reputation of the builder , the known longevity of his engines , customer service and at the end of the day what the GPS tattletale says . Hello Eddie Young and Bob Madara !

I would love to be able to afford to send it to Eddie and thought seriously about it, but dont think I can swing it. With this other motor the tattletale will likely be about 10 clicks higher

If its an unmolested 500efi never opened up its worth a lot more to most boaters. People are blue motor crazy and will pay top dollar for what they think is the best turn key solution. I feel differently but I am the minority. That being said if you have anyone other than a big name shop go through your 500 then it's the same as the custom build with a lot of unknowns