This particular 525 is one that we built. I normally wouldn't build one since they are so valuable in their stock form. This one broke a connecting rod at 190 hours. It made an absolute mess. Since the crank, rods, pistons, oil pan, etc. were all junk, it made sense to just build it. I figured it out both ways, and it was actually cheaper for me to build him a 547 ci then it was to purchase a new 525 long block and transfer the parts over. We added a larger mono blade throttle body and Hardin's flame arrestor. We made a few mods to the flame arrestor though.

We didn't do any work to the heads except replace the parts with better ones. We did change the cam though. It ended up making 635 hp and 680 ft lbs of torque. It went in a 29 Fountain. The boat ran 76 on a really good day with a light load and now runs 82 with 4 people, full of fuel in mid summer. We just finished it this past June and he already has close to 100 hours on it. He uses a boat more than anyone I've seen.
Eddie

Here are some pics of the carnage after the rod bolt broke.

I am interested in this software, please post up your thoughts when you can.

It's well worth the $$$. I'm no mechanic and I've fixed a lot of my own issues without a trip to the shop thanks to Diacom.

I thought that looked like Larry's boat. His boat runs and sounds awesome. Best sounding boat around the docks I've ever heard. His utilization is a close second behind me. We clocked over 300 hrs from mid July till end of season.

Wow... I did about 100 hours last season and I thought I was really logging them...

HyFive, did you get the software that utilizes a laptop or the "Mercury" plug in box? Pros and cons between the 2 ?

Yes, that is Larry's boat. Thank you.
When he told me the amount of hours he had put on it after less than 2 months, I couldn't believe it. But, that's what they are for. Go enjoy them while you can. Let me know if we can help you in any way.
Eddie

If you have some friends or a couple of EFI / MPI's boat owner even EFI Merc outboards, I would buy the newer version Diacom Techmate Pro hand held. - Yes the screen is a lot smaller than a laptop but out on the water the lap top is almost useless at times.

I have always had the latest greatest out on the market for scanning MARINE APPS from SPX, OTC, Merc DDT, MEDS DASH Board and Diacom.

For Merc & Mercruiser apps only especially for all the current stuff, Merc CDS is really good but damn expensive. It is made by SPX,

Diacom as of today will not scan the newer 1100, 1350 and the 1650 plus some of the other HP stuff has limited diagnostic capabilities thru Diacom. I say some of it, not all of it to be clear for the HP apps, The Merc CDS has full diagnostic capabilities with all of their own stuff.

The new Rinda / Diacom Techmate Pro hand held is very hard to beat anywhere for the money plus for techs working on different engines from the marine OEMs. It will only scan Merc outboards but not all of them in Merc stables - (90 % of them you can scan).

IMO giving out very solid advice for exactly which scan tool to buy . I have been doing this a long time, been scanning marine engines since 1993, Ford and GM and all the EFI outboards than ran thru my hands.

I bought the software that installs on a laptop. Mainly because I am very technical and want the ability to see everything on a bigger screen. I will also probably only use it on land or at the dock. I could see how the plug in might be more practical though than a laptop when out on the water.