1991 Walkaround 25 Maximum Rated Power and Transom Weight

Optimizing the performance of Boston Whaler boats
Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Sat Mar 16, 2019 12:04 pm

I may buy a 1991 25 Walkaround powered by twin 2015 Yamaha 250-HP engines. Is [500-HP] over powered?

Are [two big Yamaha 250-HP engines] too much weight on the transom? Or on a Whaler Drive?

Thanks.

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Specifications

Postby jimh » Sat Mar 16, 2019 12:45 pm

For specifications for a 25 WALKAROUND, see the data listed in the REFERENCE section at

http://continuouswave.com/whaler/reference/specifications.html#hulls24-31

That article gives a comprehensive summary of all classic-era Boston Whaler boat hulls from 9-feet to 31-feet, including their production epochs.

The maximum power for the 25 WALKAROUND Whaler Drive is 550-HP. A total engine power of 500-HP is then below the maximum rated power specified by Boston Whaler.

There is no specification for maximum engine weight. Typically Boston Whaler never published any specification for maximum engine weight or maximum transom weight for boats made before c.2002. One can make an inference about maximum engine weight by considering the weight of typical engines available at the time of production of the boat having a horsepower that would be at the maximum rated horsepower. Or by observation of the boat's static water line. See below for more advice.

Typically on Whaler Drive boats with twin engines, there MUST be an added support for the Whaler Drive. The support is a stainless steel tube that runs from the center of the transom of the Whaler Drive to the center of the hull transom, creating additional support for the weight of twin engines. This steel tube should be in place on any twin-engine Whaler Drive rigging.

On the excellent 25 WALKAROUND Whaler Drive LUCKY TWO, there are twin E-TEC 250-HP engines. Those engines each weigh about 520-lbs . There does not seem to be any problem with twin engines of that horsepower and weight as evidenced by the excellent performance of LUCKY TWO.

You can make a general inference about the weight on the transom of any Boston Whaler boat by observing the location of the engine splash well sump drain holes through the transom to the sea. If the drain outlets are just at or are above the static waterline of the boat at rest, then the transom weight is considered to be in a proper range. If the drain outlets are completely submerged below the static waterline of the boat at rest, then the transom weight is considered to be exceeding the hull designer's original intention for engine weight.

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Sat Mar 16, 2019 1:02 pm

Very helpful information, thank you.

Cheers,
Sandy

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Sat Mar 16, 2019 1:15 pm

ASIDE: the 25 WALKAROUND Whaler Drive is a fantastic boat. I don't know why they called it a "25". It is much bigger than the OUTRAGE 25 hull. It has a 9-foot 6-inch beam and is 27-feet long. It is really a very big boat.

The only downside to the 25 WALKAROUND Whaler Drive is the beam: too wide for simple trailering, as in most states the trailer will be over-wide and there may be limitations on when you tow it and how you can tow it on the highway. Also you would need a behemoth truck to handle it. But the boat can be trailered, albeit with added complexity and cost compared to boats with 8-foot 6-inch beam.

Don J keeps LUCKY TWO out of the water at a marina with indoor storage and with forklift service into the water. That method is probably as cost effective as investing in a big trailer and big truck to launch the boat yourself, although having the ability to trailer the boat will give you more range for using it.

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Sat Mar 16, 2019 1:20 pm

Regarding what engines in c.1991 would have given 550-HP on the transom: I think you could have bought an OMC V8 4.0-liter 275-HP engine in that era. I would expect that a V8 outboard would have been in the 550-lbs per engine category, if not more. So twin 275-HP V8 OMC engines would probably have been the maximum possible power in c.1991.

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Sun Mar 17, 2019 11:36 am

Your the man Jim! You are a wealth of information that is really helping to guide me through this process... I own a 2002 F250 Superduty Diesel and it probably won't be too happy towing this much weight, but it may be able to move it around some. According to the dimension and production information sheet the difference between the 25 Walkaround and 27 Offshore is about 1000 pounds of dry weight and six inches of beam which leads me to believe the 25 Walkaround will be a little more manageable for towing. However I am still considering The 27 Offshore, and I found one that has 2001 Yamaha 225's... the ones that have had some problems with exhaust corrosion. Do you think those motors should be all together avoided? Or does it just depend on the survey and if the corrective work has been done? I understand these boats are beastly but we intend to keep it in a slip at least half of the year. Thanks!

Aside: I was looking at the west coast built commercial fishing boats such as Radon, Wilson, Anderson in the 24' to 26' range but they are typically work boats and not "family friendly" (no galley or head). They are designed for safety with heavy loads in a following sea, which is our conditions when coming home from the Channel Islands. These nice beamy Boston Whalers with less dead-rise than most recreational vessels seem to be a happy compromise for husband and wife : )

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Sun Mar 17, 2019 1:45 pm

Sandor wrote:...I own a 2002 F250 Superduty Diesel ...


That is the sort of truck you need, so you've got that part of the problem mostly solved. As you mentioned, total towed weight does tend to creep up with larger boats.

I cannot offer much commentary on the 27 OFFSHORE and its ride, but I do love the look of that boat. But the 25 WALKAROUND seems to be more suited for staying aboard overnight. Its cabin is quite pleasant and accommodating.

In either boat, buying a used one that does not need an immediate re-power will be important. At today's prices, re-rigging two new 250-HP outboard engines is going to cost about $50,000. I think that factor has influenced the asking price of some larger twin-engine outboard boats that have old engines; the sellers and the buyers all know that there is a big expense looming in the near future for those hulls.

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Wed Mar 20, 2019 9:20 am

The boat I am interested in buying does not have the added support bar from whaler drive to transom... The engines only have 70 hours on them so the WD has not been burdened by the additional weight for long, but do you think it would be a problem to have the support bar installed after the fact? Or is this a reason to walk away from the boat. I will be scheduling a survey this week. Thanks!

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Wed Mar 20, 2019 12:10 pm

Hmm--I just called Don J to check whether his 25 WALKAROUND had that center support in the Whaler Drive: it does not.

Perhaps on the 25 WALKAROUND the boat has so much beam that the Whaler Drive is a much bigger structure than on the narrower hulls, and it doesn't need the center support. On my Whaler Drive (on a 22-foot hull) you can see the mounting points for the support are already in place on both the transom of the hull and the transom of the Whaler Drive. The holes are covered with stainless steel circular plates.

If the 25 WALKAROUND doesn't need the support, then there probably are not pre-drilled holes with covers in place. Also, since a 25 WALKAROUND would (just about) ALWAYS be rigged with twin engines, the Whaler Drive was probably designed to be ready for them without any further modification.

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Sat Mar 23, 2019 12:55 am

Ok, so I had a survey done on this boat today and there is water in the hull in numerous locations above the water line. He said the bottom of the boat looks good but there is water on starboard side, transom, and port bow. Maybe water got in from various fittings, rain, rubrail, etc.

How gnarly is it to fix this and to what expense?

Thanks again

Jefecinco
Posts: 1592
Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Jefecinco » Sat Mar 23, 2019 10:42 am

If the boat floats level and water is not above the waterline that indicates it is probably not unduly burdened with water in the hull. In that situation if it was my boat I would remove, seal and reinstall all hull penetrations to prevent any more water getting into the hull. I would not attempt to remove any of the existing water in the hull because it is costly, takes a lot of time and is unlikely to improve the boats safety or operating characteristics.
Butch

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Sat Mar 23, 2019 10:55 am

I don't know how to answer your question because I don't know the extent of the intrusion of water into the rigid foam between the inner and outer hulls, and I don't know the method the surveyor used to detect the water.

I suspect that it may be possible to find "water" in some part of every Boston Whaler boat. That the water has been found above the boat's static water line is also somewhat unusual. If there is no clearly suspicious point of entry for the water to get into the areas that were found to have water, there might be another explanation for the appearance of water in those areas. If the areas are all in generally high areas in the hull, there could be "moisture" in those areas that is a remnant of the initial construction.

This is just a guess on my part, but when a Boston Whaler boat is created, there is a very big chemical reaction created in the process of foaming the space between hulls. In many chemical reactions, a product of the reaction is water. Boston Whaler has always provided ducts or conduits or paths in their molds for air to escape from the mold and ultimately for the expanding foam to escape. These are called sprue holes. It seems possible that in the process of joining two hull parts together and foaming the space between them, some moisture could be retained. The moisture would escape from the interior via the sprue holes, as the foam expanded and pushed out all the air. But perhaps not 100-percent of all moisture escapes.

If the surveyor used an instrument known as a moisture meter to detect water, his instrument may have been reading that sort of moisture. It is also possible--I think--that the instrument might respond to embedded material in the hull that was beneath the probe. I think using any instrument like a moisture meter needs experience and interpretation. I hope your surveyor had experience with Boston Whaler hulls in particular

As an anecdotal report, I can tell you that on a beautifully cared for, pristine Boston Whaler hull (a 25-footer), that spends the great majority of its time sitting on a trailer in a warm climate, and has no signs of any hull damage, I have seen liquid run out a fastener hole far above the water line when a screw was removed. What came out was not clear and pure water but some sort of dark liquid, perhaps a bit of uncured resin mixed with some product of the foam chemical reaction. Something like that might be detected with a moisture meter.

I know my answer is not very definite. You will have to make a decision based on your own interpretations and on what the surveyor and the owner can tell you. I would certainly ask to be allowed to re-inspect those areas of the hull where the surveyor indicated there was water, and to explore them carefully, using a small plastic head hammer and the tapping technique, to see if there was any distinct difference in the sound of the hammer hitting the hull, which would be an indication of delamination of the bond between the hull and the foam. Be aware that a difference in sound will also occur in areas where there are imbedded reinforcement materials.

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Sat Mar 23, 2019 1:32 pm

Regarding moisture meters and Boston Whaler hulls, try reading the articles in these search results:

https://www.google.com/search?hl=en&sou ... gle+Search

In several articles Jeff--a very well informed and experienced buyer of used Boston Whaler boats--reports that moisture meters used by surveyors mostly gave false indicators of water in the hull. I recommend you read his several comments

Jefecinco
Posts: 1592
Joined: Fri Oct 09, 2015 6:35 pm
Location: Gulf Shores, AL

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Jefecinco » Sun Mar 24, 2019 10:56 am

A moisture meter would not be my preferred method of determining the presence of water in a Boston Whaler hull. As mentioned the results of inspections with the meters are not consistent and are often misleading. The hammer taping method can be very helpful if the inspector has a wood locating diagram for the boat and is familiar with the construction techniques used.

Another method used to detect water in a hull depends upon the use of an IR camera. As with any inspection method an inspector with great deal of experience using the method will more likely produce an accurate result.

What method was used by the surveyor to detect water in the hull?
Butch

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Mon Mar 25, 2019 10:57 am

He used a standard moisture meter, and unfortunately he was not very familiar with Boston Whalers. We are going to find someone else in the area who knows these boats, and hopefully has the right equipment as you mentioned. I am also a little concerned about the weight of the F250 four strokes. The surveyor wrote: "The stern displayed a high water line above the painted bottom by 1 ½", with no occupants just below the scupper drains."

Thank you gentlemen for all your help with this!

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Mon Mar 25, 2019 11:07 am

Hey Jim, I just read the old thread about moisture meters, wow, very interesting! The seller of the Walkaround said he was very "underwhelmed" by the surveyor. That's my fault. I wish I had spent a little more time finding a surveyor who really knows Boston Whalers. But his report was helpful to understand the overall condition, and lack of ongoing maintenance.

Here are some of his other findings:

"The starboard outboard forward accordion wire/fuel line run was extremely crimped in the up position, The stern displayed a high water line above the painted bottom by 1 ½", with no occupants just below the scupper drains. The below waterline through hulls were smashed in, starboard propeller was ¼” untrue. The wiring was running in every direction, askew and not bundled or anchored. In multiple areas, wiring was laying askew and not bundled, or attached to the bulkheads ever 18”. The very aged Furuno radar was intermittent. Overall sun damage, The cockpit white perimeter vinyl coamings were hard, aged, and cracking. The SS bow pulpit was bent inboard, The electric horns were not operational, Both VHFs would not return a radio check, portlights were sun aged cracked and the bow hatch displayed a crack, trim tabs were not fully functional, The faucet was corroded, trailer was not adjusted for the vessel size, being too far aft, with the weight, while the trailer port aft wheel was canted slightly, inboard, and the forward inner hub plastic seal was loose.”

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Mon Mar 25, 2019 11:41 am

Yeah, the boat needs a lot of TLC. If the boat were perfect, with low-hour quite new twin 250-HP engines, the asking price would probably be much higher.

If the "scupper drains" are still above the static waterline, that is a good situation.

If the painted water line is below the actual static water line, that means it was a poor paint job. Or, maybe the boat was in cold saltwater when the water line was painted, and it is now in warm freshwater.

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Wed Apr 03, 2019 12:13 pm

We had another surveyor look at the boat, and his only real concern is the Whaler Drive. Because it's fully encapsulated he thinks it may be "sweating" inside there giving a false moisture read. He recommends cutting it open and tapping around with a screwdriver to make sure it isn't rotten, and then installing a waterproof hatch and drain plug (much like other boat designs). What are your thoughts on this? Thank you.

jimh
Posts: 11670
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby jimh » Wed Apr 03, 2019 4:05 pm

I have no recollection of any discussion on how the classic-style Whaler Drive (Dougherty Drive) components are constructed. I would assume they are made in a manner similar to the Unibond hull, although I do not know if they have interior foam in the same density, that is, if there is some sort of two-piece mold joined together and foam is expanded under a limited sealing with a few sprue holes. There may be parts of the Whaler Drive with sprue holes and you cannot see them because they are mated to the hull transom.

But I would be reticent to start cutting into a Whaler Drive on the basis that a surveyor thinks it might be "sweating."

The later Whaler Drives seen on the Van Lancker designs are made much differently. They are somewhat notorious for getting wet internally.

The fact that the drains on the Whaler Drive are above the water line tells me more than a surveyor suspicion of "sweating."

Sandor
Posts: 16
Joined: Thu Feb 28, 2019 10:20 am

Re: 1991 Walkaround 25 Maximum Rated Power and Transom Weight

Postby Sandor » Thu Apr 04, 2019 9:30 am

Ok, thanks Jim. I'm going to post this question under repairs and modifications. Thanks again : )