I can either give you a call tomorrow or you can reach me anytime at the shop # in my avatar. I'm out of the shop until the 2nd, but I always have the shop phone forwarded to my cell whenever I'm not there so my customers can reach me 24/7. I would love to talk with you and pick your brain a little.
Thanks,
Eddie

Awesome well talk tomorrow.

One other interesting point not mentioned is that the 525's don't have a functioning knock sensor. It really doesn't need it though. The later models didn't even have a sensor present. The earlier 525's have the sensor, but it isn't turned on in the cal. They just stopped installing them in 08 or so. That will give you an idea of how safe the engine is in stock form. That explains why the engine doesn't respond to, or even need, fuel greater than 89 octane.

I've enjoyed this thread immensely. I haven't had a ton of interest in many threads lately, but this one has kept me coming back. I really like the technical, informative threads, rather then the name calling, drama filled nonsense. You won't find me posting in that crap.

Thank you for all that you have contributed. I've learned a few things as well.
Eddie

The End.

This was one of the most educational threads ever. Albeit a wake-up call for most of us this information will save some motors and a season or two. Great job to the tech pros that contributed.

Absolutey +1.... I have three of these motors; great reference material here for keeping 'em humming.

Going to do some testing with different engine oils this week. Lucas,Gibbs, and Amsoil.

+1

Agreed, great thread! I've read most of it but lost track of what was posted on which page. Can someone (Eddie maybe?) summerize what needs to be done and/or checked on a 525 broken down by hours or seasonally? Or point me in the right direction if its already posted somewhere.

I have not read all the posts up here but will add what Eddie said about the rod bolts. Mercury Racing did come out with a Service Bulletin in early 2012 about the new connecting rod torque specification. It covered many models not just the HP 525. It covered the HP 525, 575 SCI, HP 600 SCI, HP 662 SCI, HP 700 SCI. the new 565 and the QC4 v 1100 and the 1350. The scope was worldwide and the jist of the SB was ARP was no longer offering moly lube for fasteners when applying torque values.

The Correction and yes the rod bolts are from ARP and they recommended using the ARP Ultra Torque assembly lube for fastener torque values. This changed the spec. The rest of the SB reads as the following : To achieve proper screw stretch, apply ARP Ultra Torque Assembly Lube on the threads and underneath the head of the bolt and tighten to 40 Nm / 30 lb-ft plus an additional 55 degrees.

Also it would be wise not let the valve springs go over 250 hours or least have the spring pressures checked. I have also seen them very weak around that time frame. We have seen the boat owner most of the time say I have lost some RPM's (200 to 400) over the 200 hour mark of engine hours. IMO time to really look into the valve train area and change the valve springs no latter than the 250 hour mark if not way beforehand.