Seeking Input

[Capecod]

  Greetings Aquasport Enthusiasts! 

I bought a 1986 170 with a 2016 Evinrude ETec 50 HP just before the winter and am now pulling back the cover and getting my plan in place for the Osprey. I knew that I was buying an older boat with cosmetic issues with a solid engine that does really well in our local conditions.

The weather has started to hint towards spring this week which everyone in the Northeast knows indicates the beginning of boat gear buying season. When I pulled back the cover today and took a good look at what I had gotten myself involved with,  my assessment is that I really like this boat! She needs some cosmetic clean up and I have some improvement ideas but seems to be a well built and everything mechanical, electrical, structural and configuration looks solid.

I'd value some opinions from some owners with more experience with the boat about these ideas:

-Gas Tank Under Floor: There is a large hatch panel that looks like it would be simple to pull up if I unscrewed the console from the deck. If I open that up, how big a job is it to drop in a below deck gas tank, deal with venting, spot for filling, and lines to engine? In moving the console to get access, will I need to disconnect any steering linkages?

-Moving Console to Starboard: This is a creative idea that I have to create more seating along the port rail. I'm not fishing so don't have a strong need for the console to be in the center. I would plan on adding ballast to port to even out the weight.  What else would I need to consider for this project to work?

-Adding Seating: I would like to add seating along the port rail if I move the console. I am planning to build a bench out of King Starboard with some stainless legs, possibly on a hinge to tuck it away. In addition to that spot I was thinking about doing something similar across the transom area aft just in front of the engine. Anyone try anything like I'm describing?

Thanks in advance for your insights and experience. Looking forward to getting out on the water!

J
 

[RickK]

Here is a link to our "Buying a Used Aquasport Bible"
http://classicaquasport.com/smf/index.php?topic=10634.0

Run through that and see where you end up.

[Mwar410]

If the “newer ones” are anything like the older ones, the 170 is pretty weight sensitive. Just the weight of the rigging on starboard side will make it list.  You’ll have to be spot on with completely changing the layout of the deck.
I’m going to assume there’s already an abandoned tank under the floor. Something got fouled up and the previous owner just hooked up a auxiliary tank.  Is there no deck plate on the fuel cover?

[mshugg]

Your 86 Osprey most definitely came with a below deck tank.  Depending on how extensive the previous owner’s modifications were, outing in a below deck tank could be as simple as swapping out parts.  Be sure to replace hoses too.  Are the tank fill and vent still present?  One note of caution, the deck was cored with plywood or possibly balsa, so when you pull the tank hatch, be sure to seal all screws and other deck penetrations well.  You won’t know initial you start the work, but you mat find soft spots where PO didn’t seal things up properly.

As for shifting the console, lots of 17’ boats with 12 degree deadrise were built with side consoles, so no reason it couldn’t be done.  The weight of operator starboard would tend to counterbalance propeller torque.  If I were doing it, I’d go with a smaller console to maximize walk space.  In fact, I’ve often thought about grabbing a 170 or 196 and converting it to a bay boat layout with forward and aft casting decks, but 1 rebuild is enough for me.

Something to consider about using starboard for a seat base: It’s heavy, flexible and will deform with  prolonged exposure to heat.  Depending on your exact plan there may be better materials.  If you stay with starboard, you’ll need to design in additional stiffness and supports.

Enjoy your 170.  It’s a fantastic and versatile boat, and there’s a reason Aquasport sold so many of them.

[wingnut]

I’m about 90% done gutting my 1986 170, feel free to peruse photos and take a look at the innards. I briefly considered putting a tank back in the existing tub, but found it very difficult to find a tank that would fit and hold more than 15 gallons. Nothing to say you can’t have one built though - just wasn’t in my budget or timeframe. Removing the tub holding the original tank frees up a great deal of space (mine is 35 gallons now) but opens up a can of worms with replacing portions of the deck.  I am hoping to splash first time next month.

[CTsalt12]

Not trying to convince you either way, but Moeller makes poly tanks that will fit the oddly low size of the 170, they are cheap and won't rust like other materials.  You may need to do some slight, also cheap customizations like adding "L" fuel fill/vent fittings.  Topside fuel tanks aren't so bad, and there's downsides to below deck fuel tanks too.  But overall I'd take a 15 gallon below deck over a 6 on the topside.  Space is at a premium, better for weight distro, and less trips to gas up Is nice

[wingnut]

Agreed - totally up to you, but at the end of the day, if you have the time and resources, below deck has plenty of advantages.

One option that might get you a bit of extra capacity: your existing aluminum tank currently sits in a tub that is about 6" deep, and is supported by the deck. If you were to take a cutting wheel and essentially cut into the vertical faces of the fiberglass tub (after removing the actual tank) and remove the bottom, you could gain some vertical height (say an extra 2" to 3") for a new tank. This may be handy, because the fill port on a new plastic Moeller tank is pretty tall. Your tank would then be mounted to the hull, in the same location, and you could keep the current deck cap to the fuel coffin without having to remove parts of the deck.  Let me know if you want to see a photo of the underside of the fuel tank and coffin - I haven't taken it to the dump yet.

Just a thought. My deck was a spongy mess so I had to remove it either way, but if your deck is good, this may be a good middle ground.

[Capecod]

Thanks everyone and apologies for the slow response to your helpful comments. Didn't have the board set to forward emails. 

Moving console-going to tuck that one away for another season after I've used the boat a little bit to excited that its in the realm of possible--my 13 ft Whaler has a Starboard seated console and I like the configuration. 

Gas Tank--Looking through the deck plate behind the console it looks like the tank has been taken out and there is just an open cavity there. There is still a tank fill plate on the starboard rail that unscrews and I can see the filler hose below that fill plate. In between there and the coffin....there be dragons.  I've looked at the low profile Moeller tanks and they look like they would fit. I don't really need a very big tank-10-15 gallons would be ample for my use. 

Wingnut: When you say "deck" are you referring to the surface below where the tank was resting? Does that deck extend across the full hull or is just part of the coffin construction. Wouldnt I want to have the tank raised up off of the hull so that any water in the lowest part of the boat moved below the tank?

The boat has two bilge pumps which suggests to me some leakiness somewhere down in the bilge --starting the process of trying to isolate and intrusion point.

Seat: I used starboard as a replacement hatch cover/seat on my whaler after the original fiberglass/plywood delaminated and I mapped out the amount of labor it would take to grind out, reseat and glass the piece. I take your point across a long span and would likely add some re-enforcement for anything over 2 foot.  What materials do you recommend for a light seat/bench?

Thanks again everyone.

[wingnut]

Here is a crude sketch of what I had originally considered. The fuel coffin is supported by the deck - it turns down from the edges of the lid and makes a tub that the tank sits in.

[Capt. Bob]

Your 170 came from the factory with a 27gal aluminum below deck tank. It fits right onto that tank coffin with no problem. You do not want to cut out the coffin and allow the tank to rest directly on the hull itself for the exact reasons you listed. If you do decide to remove the coffin, then you will need to construct a shelf between the stringers that will allow the tank to rest on while allowing water in the hull to pass underneath from the forward compartments to the rear bilge area.

That to me is non essential work unless you are planning a complete rebuild and installing a larger tank. You should try and contact a tank builder in your area and get a price on an OEM type tank rather than an "off the shelf" one. I not knocking polys or other types as they have their place when doing a major rebuild/custom install but if just replacing the original, we got a guy in your area. Give him a call.

http://alloymetalworks.com/

Member just got this one.
https://classicaquasport.com/smf/index.php?topic=15331.msg150282#msg150282

Good luck.

[wingnut]

Absolutely, if you can find someone to manufacture an aluminum one with a very short height for the existing coffin, that's path of least resistance - much more work involved cutting and mounting. Just an option if you needed a bigger tank and didn't want to rebuild deck.

[Capecod]

Helpful stuff- thanks folks- particularly the sketch. I’m not going to do any cutting -deck and coffin are solid so I’m not messing with that. 

Can you explain the aft scuppers & drain hole on the transom below the water line and the drain line from the live well in the bow to the through hull on the starboard side. What prevents water from flowing in on both those?

[Capt. Bob]

Can you explain the aft scuppers & drain hole on the transom below the water line and the drain line from the live well in the bow to the through hull on the starboard side. What prevents water from flowing in on both those?

The transom drain plug (your second pic) is threaded inside and you install a plug in the drain BEFORE launching. That plug prevents water from entering and once back on the trailer can be removed to allow any water that made its way into the hull to be drained.

https://www.westmarine.com/buy/west-marine--garboard-drain-with-plug--P006_181_003_505?pCode=544494&cm_mmc=PS-_-Google-_-GSC%3ENonB%3EProduct%2520Type-_-544494&product_id=544494&creative=108421551244&device=c&matchtype=&network=g&gclid=Cj0KCQjw-Mr0BRDyARIsAKEFbecuWDGD9Iwos1E0lGrn670oRRq12Ysy1XgiiuUTG4x6YeL8FxmypvAaArx9EALw_wcB

The thru hulls are at or below the waterline and will allow water to enter to that same level. If your deck is lower than the waterline at any given time then yes, water will enter the scupper (thru hull) and get on the deck. The 170 is weight sensitive so you do not want to hang an overweight engine (or several fishermen) on the stern. Some members will raise the deck or use a 'valved" scupper to limit the water that enters under stern heavy conditions.
This is but one type that some members have used.



These are more for the deck drain to allow additional weight in the stern while keeping the deck dry. They are not needed for your well drain.

This displacement of water (deck higher than drain) is the principle used in calling these Aquas "self bailing". Water will exit the deck through the drain even if the thru hull is underwater at the time (on models where drain itself is higher than water level at the time). Not magic, just physics. As for your bait well, same principle. The bottom of the well is above the waterline and will displace any water out the drain even if it is below the water.

Remember, install transom drain plug first. Launch second.

[Capecod]

Aye aye capt - hear you loud and clean. First rule of boating- check the drain plug.

I think I have it:

-Put the drain plug in

- The two aft drains flow into the bilge which is pumped out by the bilge pump(s)

-The forward well drains out the through hull and buoyancy keeps it from coming up hill. I’ll assume I’ll spend all season keeping barnacles and growth from congealing in that hull opening.

-There are two other scuppers above the painted water line aft with aged rubber flaps on outside that must of once kept water from flowing one direction but now have drain plugs solids wedged from the inside. Those look like good candidates for replacement with something like your suggestion.

It’s going to sit on a mooring so having some self bailing is a good back up in additional time the bilge  pump direct wired in.

Thanks again - no doubt I’ll run into more questions....

[Capt. Bob]

-There are two other scuppers above the painted water line aft with aged rubber flaps on outside that must of once kept water from flowing one direction but now have drain plugs solids wedged from the inside. Those look like good candidates for replacement with something like your suggestion.

These are the deck drains. They are straight thru design and were EOM from Aqua. I have the same ones on my 91. A number of members have replaced that type with this:
https://www.wholesalemarine.com/t-h-marine-flow-max-ball-scupper/?gclid=CjwKCAjwvtX0BRAFEiwAGWJyZEQiCzEr5PHe85ZPe6_LLY_PLwYiCZbZrRaGAhoHjWZyO2DsOYfAahoCkv8QAvD_BwE

The type you have are readily available and work well if the rubber flap is supple. I use 3M 303 on mine.

Good luck.