Classic Montauk 17 Stern Too Low

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Marion
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Joined: Mon Jul 29, 2019 4:35 pm

Classic Montauk 17 Stern Too Low

Postby Marion » Mon Jul 29, 2019 5:04 pm

Hi everyone, First post here.

I just bought my first boat, a 1987 17' Montauk with a 2007 four-stroke Honda 75-HP and automatic bilge pump. I launched it last weekend and plan to keep it tied up at a private dock I have access too. I'll run it on weekends, so it will sit for about a week in between. I don't have much boating experience, but I've always been told to leave the bilge plug out when the boat is docked long-term (or moored) so rainwater can escape.

The problem with my boat is that the stern is sitting too low in the water so even the engine splashwell drain tubes are 1-2 inches below the waterline at static trim. I've got a couple questions about this.

First, why is the stern sitting too low in the water? Is the engine too heavy? I think it weighs 360 lbs. I'm not sure what the max engine weight is for the classics, but the owners manual for the newer Montauk 170 says 410 lbs (I'm assuming classic is lower than that). The fuel tank is under the helm seat (only 6 gallons, almost empty on my first trip anyway) and battery is in the console. There's nothing else I can move forward for better weight distribution. If not too much weight, could this be a problem of water intrusion in the hull somewhere? A rotten transom?

Second, should I leave the center sump plug in when the boat it's docked? I'm used to leaving it out, but I'm not sure how much water would fill the boat if I pulled the plug. I got freaked out when water came up into the cockpit FAST and put the plug back in. The sump drain tube is maybe 6 inches below the waterline (best guess, since the engine splashwell drain tubes are maybe 2 inches below waterline), so water really comes in when I take the plug out. I do have an automatic bilge that I can run if I leave the plugs in, but I'm worried about draining my batteries down in a heavy rain or a failure in the bilge pump system (clogged tube, pump dies, etc.) and then filling up with rain water. Alternatively, I'm worried about too much water filling the cockpit (fouling, etc.) if I leave the plug out.

Third, I left the splashwell drain plugs in yesterday because I didn't think they should be below the waterline. I know you're generally supposed to leave those out, and I'll pull them before getting underway, but is it dangerous to leave them plugged while it's docked to avoid filling with water? Again, I'm not sure how much water would fill the splashwell if I left the plugs out, but my guess is over half full.

As I said, this is my first boat so forgive any novice mistakes or ignorance!

Thanks in advance for any advice or thoughts!

biggiefl
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Re: Classic Montauk 17 stern too low

Postby biggiefl » Tue Jul 30, 2019 10:27 am

Montauk17 boats will not keep a dry deck with the plug out. They will fill with water until it reaches the console or close to it. This is why there is a bilge pump. Not all Whalers are self bailing. Many of the classics were but were designed when engines were much lighter. In the mid 1970's a 135-HP engine without power trim was only like 270lbs.

Just because the drain plug is below water does not mean it is allowing water to get inside the hull or else they would not have them. Your duty however is to make sure the drains are not compromised and sealed well.

Also check the bow locker; they usually take in water if plug is left out as well, The anchor locker will also fill with rain water if you leave it’s plug in. I used to leave the plug out and put the anchor on top of an old cushion to keep it dry so the line does not rot.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

jimh
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Re: Classic Montauk 17 Stern Too Low

Postby jimh » Tue Jul 30, 2019 5:31 pm

If you want to keep the MONTAUK 17 in the water and on a mooring and unattended for a long time, there are two options:

—leave the cockpit drain plugged and get a very good mooring cover that will keep 99-percent of the rain out of the cockpit; leave the sump pump set to auto; get a small photovoltaic cell to charge the battery; or,

—leave all the drains open and put up with the water that will collect in the aft cockpit.

jimh
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Re: Classic Montauk 17 Stern Too Low

Postby jimh » Wed Jul 31, 2019 7:56 am

A mooring cover for a boat left in the water is also a good investment because of other residual benefits. The cover will keep the sun off the boat, preventing deterioration of the gel coat, the wood, the upholstery, and any plastics.

Marion
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Re: Classic Montauk 17 Stern Too Low

Postby Marion » Wed Jul 31, 2019 10:01 am

Thanks for the replies everyone! It sounds like the motor is probably too heavy for the hull. As far as what to do about it, I'm very hesitant to test how much water will fill the boat if the bilge plug is left out since the stern on my boat is sitting ~6 inches below what it should be (as shown in the owner's manual, what others have described, etc.).

I've replaced all the old drain plugs with new ones to get a tight seal. I decided to leave the engine splashwell drains open since it only fills with about 2 inches of water, which is better than filling completely in a rainstorm. I already have a mooring cover that I put on whenever it's not in use, good to know that will help considerably. I might be able to run power down to the dock for an extra bilge pump, but otherwise I'll be looking into a small solar panel.

I'm definitely glad to hear that this isn't an indication of water soaked foam or a rotted transom, etc.

biggiefl
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Re: Classic Montauk 17 Stern Too Low

Postby biggiefl » Wed Jul 31, 2019 11:06 am

Be very careful with running AC power to a boat in the water, even with a trickle charger. It can use the water as a ground and cause serious electrolysis. I used to keep my boat in a slip for the weekend and some people "near" me would run AC to their boat for the livewell to cycle overnight. I would pull the boat on sunday and any exposed metal would be white(like corrosion) from the electric running through the water. I can't imagine what a thruhull would look like after a month or so.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

Marion
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Joined: Mon Jul 29, 2019 4:35 pm

Re: Classic Montauk 17 Stern Too Low

Postby Marion » Wed Jul 31, 2019 3:12 pm

Biggiefl, that's very good to know! I'll definitely do more research on that and solar options before doing anything.

I also might consider downgrading the motor to something lighter since I don't really need 75 hp on this light little hull. I got old specs from Boston Whaler that say minimum hp for a '87 Montauk 17' is 35 hp. If I could drop to something like a 60 hp four stroke, eliminate this problem, and still have enough power to have fun, then that might be the way to go.

biggiefl
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Re: Classic Montauk 17 Stern Too Low

Postby biggiefl » Wed Jul 31, 2019 3:16 pm

There is a guy here with a 60 Honda and he claims 35 @ WOT and can pull the plug. Personally I would not bother and enjoy the boat with a pump.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

Marion
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Joined: Mon Jul 29, 2019 4:35 pm

Re: Classic Montauk 17 Stern Too Low

Postby Marion » Wed Jul 31, 2019 3:30 pm

Biggiefl, do you know if it's a four stroke? I don't want a two stroke, but it would be good to know if dropping to 60 hp would be enough to be able to pull the plug.

jimh
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Re: Classic Montauk 17 Stern Too Low

Postby jimh » Thu Aug 01, 2019 12:35 pm

HONDA only has made four-stroke-power cycles outboard engines, beginning with very large and very heavy engines that would swamp a small skiff.

The weight of current model HONDA engines should be available from the HONDA MARINE website. Their engines have gotten smaller and lighter over the years.

The principal problem in owning a HONDA engine is finding a dealer. Many of the dealers listed only sell small portable outboard engines.

biggiefl
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Re: Classic Montauk 17 Stern Too Low

Postby biggiefl » Thu Aug 01, 2019 2:04 pm

Honda never made a 2 smoke as Jim stated. Again....I would enjoy as-is like 98% of every Montauk owner does.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).

Bigbear
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Re: Classic Montauk 17 Stern Too Low

Postby Bigbear » Thu Aug 01, 2019 2:59 pm

Do you boaters also put a drain plug in the drain in the anchor locker? I have left mine open and have never given it another thought.

Thanks

biggiefl
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Re: Classic Montauk 17 Stern Too Low

Postby biggiefl » Thu Aug 01, 2019 3:05 pm

As per my post above from 7/30:

Also check the bow locker; they usually take in water if plug is left out as well, The anchor locker will also fill with rain water if you leave it’s plug in. I used to leave the plug out and put the anchor on top of an old cushion to keep it dry so the line does not rot.
On my 24th Whaler. Currently in the stable: 86 18' Outrage, 81 13' Sport(original owner), 87 11' Sport, 69 Squall(for sale cheap).