That would be mine. I hope you thought of changing out my fresh water muffler bearing for one that is salt water compatible. . I didn't see it on the bill :)

That was yours. I threw the muffler bearing in for free. I do that for all of my favorite customers. Consider it an early Christmas present.
Hope you guys are doing well. If I don't talk to you before Christmas, you and the family have a wonderful Christmas and great and prosperous New Year.
Eddie

Thanks Eddie, you guys have a Merry Christmas as well.

As someone who is searching for an entry-level cat with 525EFIs as the next boat, I greatly appreciate everyone's posts with info in this thread. Thank you guys!

Great first hand info here!!! I find it interesting that 20 years ago merc was building 500 bulldogs, 525sc, 600sc's, and 800sc engines that went longer between rebuilds than these 525efi's. Kinda sad actually.

The 120psi of seat pressure baffles me. The camshaft isn't exactly what I would call mild, from a lift and duration standpoint.

Eddie, have you seen signs of the lifters lofting off the cam lobes? Maybe the valvetrain after some time is just becoming greatly unstable .

Understand that I do not use my 525 fountain in salt water. That's what my outboard boat is for!! I also keep the 525s sprayed with wd40 or red corrosion x. They have no corrosion that I can see.

I only race my 525 at WOT. I don't recreational my boat so my opinion is based on WOT time only. I have never blown up a 500 carb,500 EFI or a 525 EFI. We run them hard for at least 125 hours at WOT. At that point we will change the springs and we have never seen a signal MPH gain. I think the 525 is a fantastic platform for the average boater to step it up compared to a stock set up. Remember when you do a rebuild at merc. for that $12K they give you all your parts back which includes the old set of heads loaded with all the parts. IMO the failures are based on age and use of the product. Change your oil, test your headers and pin the throttle is my suggestion. Run it till it blows and you may be shocked just how long it last.
Is there anyone out there with more than 400-500 hours on a 525?

I heard if your Mercury Racing power has the gold color rockers change them at 200 hours or before.

Awesome post!

Springs and rockets are the weak link, the Crane rockets arms Merc is using now is junk. Like Eddie meantioned in his post, you have to go and chase the needle bearing though the motor. The motor builders I have spoke to all say the same thing, and are staying away from them.