5 year / 300 hour Service/Overhaul/PM (Preventive Maintenance)

[Mainah]

I decided at 5 years and 297 engine hours (close enough to 300) that it was time to do a PM deep dive. Performance wise it still hits 50mph and was not anything indicating something amiss but wanted to do this for peace of mind and to keep up on things. I went deeper than needed and learned a few things. This will be a long post so directly below is a list of the things I did and whether needed or overkill. Below the list are some thoughts and observations.

Pumps

• Pulled pumps - Needed
• Filed small nicks on leading edges impellers - Needed
• Completely disassembled pumps - Overkill
• Removed bearings - Overkill
• Ran all parts through industrial sonic cleaner with simple green extreme - Overkill
• Reassembled per manual using all factory recommend consumables - Needed

Clean Out Plugs

• Completely disassembled - Needed
• Ran all parts through ultrasonic cleaner - Needed
• Reassembled with plug rebuild kits - Needed
• Cleaned pump housing area where plugs seat - Needed

Intake Grates

• Removed and sanded off flaking finish - Needed

Pump Tunnels

• Cleaned with steel wool - Needed

Hull

• Used trailer mount boat jack system to raise boat off bunks - Needed
• Removed and cleaned bunks - Needed
• Mixed up spectrum gel coat (not patch paste) to bring back bottom hull to factory new by filling all minor imperfections that had accumulated - Needed but also overkill
• Wet sanded, compounded, polished, waxed entire bottom hull to like factory new - Needed but also a bit overkill
• Resealed under rub rail and a couple of through hulls

Engines

• Oil/filter change - Needed (I do this every 50 hours anyway which is already overkill)
• Spark Plug change - Needed (I do this every 50 hours anyway which is already overkill)
• Greased output bearings - Needed (I do this every 50 hours anyway)
  • I did not remove the bearing assemblies after seeing great condition of pump bearings
• Checked air filters - Needed
• Checked all fasteners and electrical connections - Needed
• Re-secured engine compartment foam with 2 inch wide nylon straps - Needed

Electrical

• Checked all connections

Interior

• Checked all fasteners - Needed
• Full deep clean - Needed
• Tested all systems for correct operation - Needed

Ballast System

• Replaced one ballast pump that tended to go into thermal shut down mid pumping and then start back up once thermal switch allowed it to - Needed
  • I did replace the impeller on this pump last year which did not help anything
  • I am going to take apart the old pump when I have time to see if I can figure out if just a bad thermal switch or if something else was causing it

Accessories

• Replaced mooring cover - Needed
• Replaced Bimini - Needed (We leave Bimini deployed most of the season as boat lives on a lake)
• Inspected life jackets and verified still a good fit for each person - No changes but needed
• Inspected throwable - No changes but always do this
• Replaced old flares - Needed
• Inspected signaling devices - No changes but always do this
• Inspected medical kit - No changes but always do this
• inspected on board tool kit - No changes but always do this
• Inspected tube, wakeboards, surfboards - Needed (found loose binding mounting screw
• Inspected dock lines, fenders, anchor, anchor line - No changes but always a good idea

Upgrades

• Replaced factory main power wire harness with new 0 gauge - Time will tell if this solves a minor annoyance
• Installed 3 Hangtytes on cover - Much better than poles for my use case

With everything above complete she runs just as she did before. I did not find anything major but I do keep up on things so I was not expecting to. The biggest wear item I saw was with the pumps. The impellers still looked in good shape but the was just a bit of cavitation streaking discoloration and the leading edge dings. If things were worse I would have replaced them. The wear rings had light scarring from the impellers but nothing major. I cleaned them up with some steel wool but did not get aggressive as I did not want to remove any material. The bearing housing/ducts have some minor leading edge pitting either from debris or cavitation; I am not sure which. Not terrible and given performance I did not replace them. When removing the cones there was suction which told me things liking good with the grease and it was. The bearings looked and felt great after running them through the ultrasonic so I reused them. I stuck with the factory epnoc when putting everything back together. At 10 years or 600 hours (perhaps sooner) I can see the impellers, duct/bearing housing, wear rings, seals, and bearings needing to be replaced. I will let performance and part inspections continue to be my guide on this. The full disassembly turned out to be time consuming and overkill but at least I was able to verify condition of everything and run all parts through the ultrasonic for good measure.

Being able to get to entire hull with the boat up on the trailer mounted boat jacks was great. These were a new purchase fo me this year and sad I waited so long. I did consider other jack systems where the trailer can be removed. I landed on the trailer mounted system as it does not take much storage space and is generally safer for a novice to use than methods where the trailer is removed. I did use a beefy support for the tongue as opposed the the trailer mounted tough jack and used a bottle jack under the rear cross member of the trailer to better steady everything. The ends of the bunks had cause some rub marks on the hull and the were some minor nicks and scratches. Everything shows on the black bottom. Redoing the entire hull below the waterline was certainly time consuming and overkill but I feel better with it looking like new again.

The clean out plugs had started to become more difficult to remove. I am glad I decided on full disassembly with dunk in the ultrasonic and rebuild kits installed. They work just like new again.

Obviously we use the boat a lot. A lot of that use is for tow sports which does put more stress on the various components. I mitigate the high usage and tow sport stress by staying on top of maintenance. The frequent oil/filter changes and 4t full synthetic oil can only help in my book as I subscribe to the studies that show more frequent oil changes with high end products do mitigate engine wear. All in all I am happy that I did all of this and found no surprises lurking. I also got to buy a few new tools and love having the right tool to do about any job that pops up on hand. Maintaining a boat is not cheap (time or money) but ensures that will serve us well.