Reliable 500+ HP Merc motor

[AllDodge]

Been looking at the Merc 540 EFI. Have also looked at the 565 but assuming this motor is like the older 525 which requires head work every 200 to 250 hours. Is the 540 a reliable motor which you can just run with regular 20 hour oil changes or does it need more work?

 

[Q4mtxUS]

Plug and play...Merc = reliability
Dig it?

 

[AllDodge]

No, not really
While the motor my be reliable (sort of) does it need more then oil changes thru 1000 hours?

 

[Q4mtxUS]

AllDodge, welcome aboard. Soon, members will be chiming in and directing you to free swag and such. Do follow their directions.

Please understand that 200 - 250 hrs is a long time for me here in the PNW (go Ducks) so any Merc from a “wacker” to a Merc racing 1800hp, I consider to be “reliable” but, I am a mechanic and only take care of my stuff, so with that, everthing to me is “reliable”. Regular maintenance my man.

See what I’m sayin?

 

[AllDodge]

It's all good, and thanks
I'm on several forums (18K post on iboats, less on others) and trying to get a consensus currently. I'm looking at a brand new from Merc 540 EFI and trying to decide, do I continue to try and fix the issues with what I have (500+ HP 509), or pull it and install a new 540 EFI

 

[Q4mtxUS]

You will get the answer from the many mambers on here, which I have trusted for years, very soon. There are many highly respected and reputable engine builders on this site that will help you. Stay tuned and Happy Thanksgiving to you and yours, and again, welcome aboard.

 

[BDMar]

You will get many reliable hours out of either of those engines. However, no high performance engine will go 1000 hours without valve train maintenance. One of the ways anyone gets more HP out of an engine is with a more aggressive camshaft and valve springs. With that comes periodic maintenance. We recommend 300 hours at the most before replacing lifters, springs, rockers, and push rods.

 

[AllDodge]

OK thanks for the info