ABA Boat Maintenance & Repair Questions and Responses

The information contained herein is the opinion of ABA member and marine mechanic Tim Harrington of Madison Marine Service, Harwich, Massachusetts. Tim is responding to a question solely based on the information an ABA member provided. Neither ABA, nor Tim Harrington, nor Madison Marine Service assume any responsibility or liability for events that occur due to actions you or others on your behalf take based on the information given in Tim's response.  You are proceeding at your own risk.

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Propellers

A. With that Volvo drive you should be able to remove the prop. You did not state if you have a dual prop system. In that case, would need the inside prop nut wrench.

Your prop sounds like it has been on for a while and is stuck from corrosion and from the grease getting old. On occasion, I have had to carefully heat from the outside and tap with a RUBBER mallet to remove a prop. You may be able to soak it with penetration oil and tap it loose. Either way, when you remove the nut and washer you should be able to pull it off.

Once off, you are probably going to have to purchase a new hub and have a shop press it in, or purchase new.

Q. I own a 1985 22' Sunrunner with a Mercruiser V6 motor. I have not been able to obtain a copy of the original owners manual from Sunrunner and do not know what the manufacturers specs for the prop pitch are. Was wondering if you are able to get this information.

A. You do not need the owner's manual from the boat manufacturer. You need to get together with a technician and go through the Merc prop book and match the prop to your power. Then you can make choices on the performance end for your boat.

Q. While winterizing the outdrive this past weekend, I found that there was about 1/16 to 1/8 of an inch play stern to bow in the prop shaft. Is this acceptable or do I have a problem? There are about 3090 hours on the unit and about 30 hours on the upper unit.

A. With regards to your outdrive, I suggest checking to make sure your thrust washer is in place and that all washers behind the nut are in place.

If you can pull your shaft in and out without the prop installed it is indeed time for service. Also did you notice if your gear oil came out clean? Did you have water penetration when you serviced the lower unit in your winterization? That also will give you a clue as to the condition of the seals, etc.

Q. I just purchased the new engine (Honda 200) for my 2001, 23' Bay Hawk. It has a four-bladed/21 pitch prop, 25-inch shaft. Problems- 1. the boat comes out of the hole real slow, it takes 300 to 500 feet to get up. Max rpm's-4000, after about 300 yds the boat starts porpoising without any trim movement. Is there any thing I can do to help my situation?

A. I have rigged and installed Honda's for a dealership here on Cape Cod. You're way below your rpm, especially on a brand new 200! You will only get the performance of your engine's capability at max RPM by matching the proper prop with your power! I am sure you can watch your RPM change as you try different props.

My suggestion is to go to the dealer or direct to the Honda web site, www.honda-marine.com/hmframeset.htm for support to find the correct pitch for your engine. You will find a great deal of performance and speed change if you do so.

You have a great engine, fine tune her and it will serve you a good many years.

Q. I was curious to know why my boat pulls so hard to the right. I don't see a problem with the prop. I just bought the boat and was curious what the problem may be. I have heard of stabilizers and such but just not sure so I'm asking the expert. Thanks for your help.

A. I have received your question regarding your problem with torque pull on your boat. I see that you have 115 hp on a 15' boat. I hope that it is equipped with seat belts!

Above your prop you will see a fin with a single bolt. Mark the position of the trim tab plate and move it in a counter direction to the prop rotational direction in small increments. This trim tab is there to counter the torque that the prop creates in rotation. Following this procedure should stabilize your pull problem.

Q. I bought this boat used last year and I want to replace the propeller. It has the number.48-78122-210 on it. How can I find out if this is the recommended prop for this boat? Also can you tell me the pros and cons on stainless steel vs. aluminum or composites? This boat is inboard/outboard with a 4.3LX/V6

A. I received your question regarding your boat and prop from the American Boating Association.

I tried to cross reference your prop based on the information you gave me and also tried to see if your number 48-78122-210 was superceded. My research leads me to believe that the prop was part of the Black Max series of Merc. The best thing to do is to go to a local Merc dealer and match your prop to the outdrive. You should find several to pick from for optimum performance. You want to pick a pitch that allows you to operate close to your engine's maximum rpm at full throttle. Also keep in mind that for every inch you go up in pitch, you will decrease rpm by about 200 rpm. Conversely, if you decrease in pitch by an inch your rpm will increase by about 200 rpm.

The second part of your question was about stainless steel vs. aluminum vs. composites props. The decision is one that I leave up to the boat owner. I tell my clients to consider the environment that they will be boating in. You can get better performance from a stainless steel prop, but a stainless steel prop is also more expensive. One thing to keep in mind is that stainless steel props are more apt not to give way upon impact, thus putting the stress on your outdrive or lower unit! In this case, aluminum is a little more forgiving and it is easily rehabbed. The amount of damage caused to the mechanical ends of the drives can get expensive.

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