MaxProp Maintenance

Our MaxProp is relatively maintenance free — just an annual greasing, being kept clean and replacing the MaxProp zinc and the shaft zinc and it just keeps humming along.   But it certainly looked scarey when we hauled the boat!  Even though our diver had cleaned it six weeks previously, we were surprised at the barnacle growth and even more surprised that it motored us up to the yard without overheating the diesel!  Whew!

After chipping off some of the barnacles, and breaking a scraper in the process, we quickly discovered we’d need additional help!  We used some muriatic acid, painted it on, waited about 10 minutes and scraped again … more growth off!  We repeated the process and then rinsed the acid off the prop with water.  Now it was looking better and after a bit of sandpaper, it looked closer to what a maxprop should look like!

David removed the MaxProp zinc and the shaft zinc so we could replace them after getting the prop regreased.  In the process, he noticed that the blades seemed to wiggle side to side – not just the normal blade movement.  Hmmmm….

After 11 years and 11,000 miles, the extra play caused us to call Fred at PYI.     If you ever need anything or just have a question about your MaxProp, PYI and Fred Hutchinson 425-355-3669 is the best resource you can have!   Fred reassured us our prop was fine — he asked that we measure the wiggle.  It measured less than 1/8 inch.  Fred said that was normal on a 3 blade classic MaxProp with the age and use our prop has had.  He said just to add the normal grease and the play would go away.  We did and he was right!  🙂   I love it when something works!

We added the grease with a normal grease gun through the MaxProp provided grease nipple, then added the new zincs and at least the MaxProp is ready to go back in the water!

MaxProp Cleaned Up & Ready to Go Back in the Water

Now if just the rest of the boat was ready to go back in the water!

Do you have comments or more information about MaxProp maintenance?  Please leave a comment and share!  Cheers!  Jan


  1. Tom McNulty says:

    Hi Jan,
    I purchased a used Max-Prop on eBay last week. I sent it to PYI for them to go through it for me.
    I am hoping it reduces the prop walk in reverse with the added benefit of ~1/2 knot faster speed.
    Have you and David been pleasaed with your prop?

    • Hi Tom! Yes, we’ve been pleased with the MaxProp, and it’s 11 years old now! We’re not sure about the extra .5 knot, but David likes the way the boat handles in reverse much better. Hope all is well with you and that you’re enjoying the book! If you get a chance, snap a picture of you and Kathleen with the book in your galley… or just the book, or in the cockpit or raising the sails or wherever and submit on the sidebar on Commuter Cruiser that has pics of people with their cookbooks. 🙂 THX & have a great day!

  2. Was the 1/8″ play in the prop while it was fully feathered or opened position. Getting ready to haul and check our Max prop. Hoping the grease will settle ours down a little as well. We notice sometimes some vibration when slowing down then powering back up. Seems like maybe one blade doesn’t full open? The fix is to slow down, back to neutral, reverse then back to forward and all is good. Max prop says probably needs grease.


    • Hi John! The play in our maxprop was overall, not just feathered or opened. After David greased it, it seems fine. We’re not back in the water yet, so we don’t know for sure, but it works perfectly in the yard! 🙂 Another variable is any barnacles you might have collected. We had barnacles that seemed to be causing most of our vibration. I hope your “fix” is as easy as ours was!

  3. Thanks Jan, we’ll find out in the morning when we haul. Also spoke with Fred at PYI and he confirmed the 1/8″ play as max. If we have more we’ll pull it and put our spare 2 blade prop on and send back the Max for an overhaul. Hoping for the grease fix!!! Hope you get back in the water soon and get South!
    By the way, Captain Beth loves her cookbook!
    S/V Norstar

    • Hi John! We were very nervous about the grease fix, but it worked, so we’re hoping for similar results for s/v Norstar! Glad to hear Beth loves the cookbook – hopefully it will be the source of many enjoyable meals! 🙂 Cheers — Jan

      • Jan,
        We did have at least 1/8″ of play but as you indicated the grease took most of it out. Seems the hub was pretty dry of grease as most of it had washed out since last haul. Power washed the bottom and touch up a few spots with paint and splashed back in after only out for 3 hours. Bottom was in great shape and we are good to go! Whew! Lucked out on that one! Thanks for the tips!
        John & Beth
        S/V Norstar

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