Was looking for info from some seasoned boaters who can give me the general hrs you can expect form Mercury's 525 efi before an overhaul. Well maintained of course

Do the valvetrain around 200-250 hours,then rebuild the whole thing at 500-600.That is the way I would do it. I know others would not go that long and most will just run it till it blows. I run my stuff hard but I don't try to kill it. I have seen 500efi's go over 1000 hours with nothing but oil changes but I would never push them that long.

The 525 is a great motor.

Thanks...Just weighing my options...496 HO or 525 efi's in a 370ss.

The first one blew up after 164 hours of racing!!!!!!!!

Without touching it befor . LOL ,,,,did not even change the sparkplugs ?!

The 100 less hp feels like alot more, because it is, the 525 will have closer to 550 hp the 496 Mag Ho. has a lot less grunt in the midrange, I would go 525.

Yea...100hp x 2 is alot... I kinda figured that... but I wasn't sure what the difference was as far as wear and tare. But you gotta pay if you wanna play!!!

This is exactly what I have been told. I have been doing ALOT of research on buying HP525's. That is Mercury Racing's opinion too. If you're interested I have a pair of 496HO's with 50 hours on them for sale. Not the same, but just to let you know. They're alot less money.

Really depends on how it is treated. We have seen 500efi and Hp500 go 600-1000 hours before rebuild. However with any racing motor plan on replacing the springs about 250 hours, valves/springs 500 hours youget the idea.

So the 525efi is a better motor, so I would expect the same if not better.

WILL

Well I'll be heading to the New Orleans Boat show this weekend so I'll get some input form the dealers and maybe the Merc guys will be there too so I can see what they have to say...but real world advice and experience is more important than a sales pitch to me...Thanks for all the info