1974 Aquasport questions

[AquaNewbie]

I acquired a 1974 170 Aquasport recently and it is in pretty good shape.    Not much to do to it other than fix fairly simple things.
The deck is solid.  The original cushions in front of the console needs to be replaced.   Apparently it was garage kept up until this year.

The mechanical steering cable that runs to the 65 hp Evinrude is shot.    It still works but the wires around the inner core are broken at the turn that goes down into the channel under the deck.
What is the opinion..  should I try and just replace that cable or scrap the steering system and install a hydraulic?   I'm planning on keeping this boat for 10+ years so if I need to put some $$ into the steering, I'm ok with that.    The bend to get the original steering cable into that channel under the deck is severe.    But the existing cable does not bind at all.  The steering is very "free".

The "coffin" that holds the gas tank was full of water that I could see through the plug over the gas gauge.   I pulled the coffin cover and pumped out the water and am letting it dry out.
Is there no weep hole to allow the water out of this "coffin container"?
Under the coffin cover was a sheet of soft foam rubber that holds water like a sponge.   I pulled that out.   Is there a reason why I should replace that after it dries out?

The rubber fuel line under the coffin cover is rotted out - probably from the wonderful ethanol in our gas. :-(      I have seen this before on older cars.
I suspect this is why the guy sold me the boat cheap.
So I'll replace the gas line and replace the coffin lid and reseal with caulk (?).    I don't see any other way that is sealed.    I believe they used clear silicone before.

The gas tank is aluminum and appears to be in very good shape.   This is a fresh water boat.   

Anything else I should look for?    I have no plans to tear the hull apart as it doesn't seem to be water logged at all.   

I am going to sew up a nice cover for it to keep the water out of the boat over the winter.   I live in an area of Indiana that was part of the Great Black Swamp.    And the weather her suits our history.   We get a lot of rain.   More than Michigan and southern Indiana. 
Dave

[boatnamesue]

What is the opinion..  should I try and just replace that cable or scrap the steering system and install a hydraulic?   I'm planning on keeping this boat for 10+ years so if I need to put some $$ into the steering, I'm ok with that.    The bend to get the original steering cable into that channel under the deck is severe.    But the existing cable does not bind at all.  The steering is very "free".

Well, my 2 cents is that steering is pretty important and anything dysfunctional having to do with such requires immediate attention.  With that said, replacing mechanical steering cable is not too expensive.  You could go big by installing hydro steering as you mentioned, but this is more a preference than requirement.  I have mechanical steering on my '76 170 and I have no issues, total comfort and ease with steering in any condition.

The "coffin" that holds the gas tank was full of water that I could see through the plug over the gas gauge.   I pulled the coffin cover and pumped out the water and am letting it dry out.  Is there no weep hole to allow the water out of this "coffin container"?  Under the coffin cover was a sheet of soft foam rubber that holds water like a sponge.   I pulled that out.   Is there a reason why I should replace that after it dries out?

See the photo below.  This is a photo of my fuel coffin prior to my recent new fuel tank install.  There are 2 red circles on the right side of photo.  These circles represent where a hole exists.  I can't tell you if these holes were drilled by manufacturer or done by an previous owner.  Be that as it may, if these 2 holes were not drilled through in my coffin I would have done so before installing new tank.  It is crucial for long term fuel tank integrity to allow water to exit the fuel coffin.

When I pulled my old fuel tank, it was laying on a thick black rubber mat, completely soaked with water, and in my case fuel, since I had a leak.  It must of been installed by previous owner, or even the owner before previous.  Either way, it was a very poor decision to use rubber, or any other material that does not repel fluids.  So it goes without stating you should not reinstall the rubber foam after it dries out....because it will again become wet and stay wet, thereby leading to crevice corrosion.  The link below directs you to a thread I completed earlier this year when replacing my fuel tank.  You'll find details on how to prep and secure your current tank.  Let me know if you have any questions.

https://classicaquasport.com/smf/index.php?topic=14273.msg141575#msg141575

The rubber fuel line under the coffin cover is rotted out - probably from the wonderful ethanol in our gas.
So I'll replace the gas line and replace the coffin lid and reseal with caulk (?).  I don't see any other way that is sealed. I believe they used clear silicone before.

Correct.  Standard marine grade clear silicone does the job of sealing the fuel hatch.
 
Congrats on the new boat.  We love to see pictures, so please post some when you have time.  Good luck.

[AquaNewbie]

Hi Boatnamesue,

Thanks for the reply.  I did more work on the boat today replacing the fuel line that runs from the tank to a fuel shutoff valve that is mounted on the top of the coffin lid. 

The old fuel line was way beyond leaking ..it was literally falling apart.   

But that is done and at the same time I realized why the foam was there!  The fuel line would bang on the tank top and make noise without the foam.   However I am not going to replace the sponge foam, I have some rubber closed cell pipe insulation I will put around the fuel line to prevent the hose from banging on the tank top.   

The steering on this boat is a Teleflex so I will look for a replacement cable and go that route. 

Coffin drain holes:  So the area just below the tank coffin, I would think that there must be a clear space below coffin??   I'm tempted to take a long installation drill bit and run it down behind the tank into the void space under the coffin  just to make sure the coffin has a drain hole...  but perhaps this is risking making more problems?   I don't want to remove the tank unless I have to and it appears to be holding fuel without any issues so far. 

Something else.. I need to replace the fuel gauge on my tank as its stuck.   And I need to replace the clear plastic plug over the tank gauge or just replace the entire access port assembly.    The clear plastic plug is smaller than the threaded opening so it doesn't thread into the hole and seal at all.  It just sits in the opening.  Not good.

I'll get some pictures.   

Dave

[boatnamesue]

Hi Boatnamesue,

Thanks for the reply.  I did more work on the boat today replacing the fuel line that runs from the tank to a fuel shutoff valve that is mounted on the top of the coffin lid. 

The old fuel line was way beyond leaking ..it was literally falling apart.   

But that is done and at the same time I realized why the foam was there!  The fuel line would bang on the tank top and make noise without the foam.   However I am not going to replace the sponge foam, I have some rubber closed cell pipe insulation I will put around the fuel line to prevent the hose from banging on the tank top.   

The steering on this boat is a Teleflex so I will look for a replacement cable and go that route. 

Coffin drain holes:  So the area just below the tank coffin, I would think that there must be a clear space below coffin??   I'm tempted to take a long installation drill bit and run it down behind the tank into the void space under the coffin  just to make sure the coffin has a drain hole...  but perhaps this is risking making more problems?   I don't want to remove the tank unless I have to and it appears to be holding fuel without any issues so far. 

Something else.. I need to replace the fuel gauge on my tank as its stuck.   And I need to replace the clear plastic plug over the tank gauge or just replace the entire access port assembly.    The clear plastic plug is smaller than the threaded opening so it doesn't thread into the hole and seal at all.  It just sits in the opening.  Not good.

I'll get some pictures.   

Dave

Unless you've got an excessive amount of length of the fuel pickup line it shouldn't bang against the tank.  And even if it did, it's not causing harm and you won't hear it.  If you're going to wrap the fuel pick up line, just make sure it doesn't retain fluid, rather wick away fluids is best.  But I don't think you need to wrap this line.  See picture below of my new tank, just prior to sealing hatch.  You'll see the fuel pick up line is not wrapped, just resting on tank.



This picture below is as if you stuck your head under the deck near the transom and looked forward towards fuel tank.  This will give you an idea of how the fuel coffin is mounted in between port and starboard stringers, forward and aft cross beams.  There is plenty of clearance between the bottom of coffin and bottom of bilge to drill holes into the coffin.

I'm not familiar with the clear plastic plug you're referring to that goes over tank gauge.  Are you talking about the fuel sender?  Or maybe you're referring to the circular threaded port access hatch to the fuel sender.  Take pictures and we'll see.

[Capt. Bob]

You're talking about the deck plate and its cover. If it doesn't fit,chances are the PO lost/broke the original (which did fit) and replaced it with something else. The clear deck insert was for viewing a mechanical fuel gauge on top of the tank. If you replace that type with an electrical unit (sender) and thus have a remote gauge in the helm, you can use a solid cover if you choose.

https://www.westmarine.com/buy/west-marine--screw-in-deck-plate-6-smooth-white-clear--11743051?cm_mmc=PS-_-Google-_-GSC%2520-%2520Product%2520Type-_-11743051&product_id=11743051&adpos=1o9&creative=108421552924&device=c&matchtype=&network=g&gclid=CjwKCAjwmqHPBRBQEiwAOvbR84oCvbKON4rp0PalOr2zcZulIgakpvoFoAORXbFqpPnTF84S4mmaaBoC1PoQAvD_BwE

As to drain holes in the coffin box. We have seen some drilled and of course other members have drilled them (myself included). The original reason for the coffin box and no drain hole was to allow a fuel tank to be mounted below deck and to insure should a leak develop, the fuel would not drain into the bilge. That stated, if you seal the hatch and deck access plates properly, you will have very little water (your ultimate goal) get into the coffin. You may also wish to consider using 3M UV4000 as your sealer in lieu of clear silicon. It retains it color (white) quite well, cleans easily and adds a stronger adhesive element (yet is easily removed) than silicon. Just another option to consider.

Good luck.

[AquaNewbie]

Sorry for the confusion.   Yes, I am talking about the deck plate. which is directly over the tank gauge.    The deck plate was likely originally a clear plate since the tank gauge a mechanical gauge with a dial readout.  The gauge in the tank needs to be replaced or at least the dial needs to be replaced, but it appears to be a standard Rochester 6700 series mechanical gauge.  I wonder if this tank wasn't replaced long ago?    It appears to be a 28 gallon tank.   The part number is A28 and it is a Tecstar Tank.  The label has a gallons field but it is unreadable.   The fuel hose goes from the tank, through a hole in the coffin lid, to a fuel valve that appears to have been added and then a line goes into the trough to the engine.    The valve looks like an add on.

I'm ok sticking with a mechanical gauge.  Less things to break, wire, etc.  I found one on Ebay that I think I can use.    Rochester Gauge offers the same gauge with a sender attached to the front of the dial.   I could always add one later.   28 gallons of gas should last a while, I hope.   

Whats a guess on miles per gallon for this boat with a 65 hp 2 cycle  Evinrude? 

So I can see why it might be a bad idea to drill holes in the coffin.    Get a tank leak and I could have a hull full of gas and vapors... 
Maybe I can just dry out the coffin and seal it up.   I might be optimistic in thinking that can be done.

Has anyone rigged vents to get air moving through the enclosed space in the hull.

I have a brass/bronze garboard type drain hole in the lowest part of the transom with what looks like 1/2" NPT female threads. 
The previous owner didn't give me the plug.   

That UV4000 looks like good stuff.   I'll see what I can find locally.   Its paintable, which is really nice in case I decide to paint the floor in the future.  I need to get this dried out and sealed before the end of the weekend as we are suppose to have heavy rain for days and I don't have a cover for this boat yet.   Perhaps I should blue tarp it for the time being.   But that never seems to work well around here as we oftentimes get 40-50 mph winds when a front moves through which is a quick death for a blue tarp. 

Dave

[boatnamesue]

Whats a guess on miles per gallon for this boat with a 65 hp 2 cycle  Evinrude?

So I can see why it might be a bad idea to drill holes in the coffin.    Get a tank leak and I could have a hull full of gas and vapors... 
Maybe I can just dry out the coffin and seal it up.   I might be optimistic in thinking that can be done.



Dave

Couldn't begin to guess what your engines average mpg at an average rpm.  Many variables affect this fuel consumption, none more than load.  Get a fuel flow meter and test it out.  Or go old school....have a known amount of fuel in tank, run a known amount of distance for a known amount of rpms.  Check fuel level.  Then it's up to mr. mathematics.

I definitely understand the logic of not having coffin holes to allow moisture to pass, in the event you have a fuel leak.  In my particular situation, I keep my boat trailered with plugs out.  When I reach boat ramp, I back boat down but do not submerge.  Get out of truck, undo straps, bow chain, apply ropes, insert plugs, etc.  This is the time when water will exit transom plug hole, had it rained since last time I launched boat.  I experienced the fuel leak scenario first hand.  I went about my routine backing boat down, getting out, etc., as described above.  I noticed what I thought was an excessive amount of water exiting transom plug hole.  It just kept coming out.  Then I cupped my hand under the stream and this water did not feel like water....very cold to the touch.  Brought hand up to nose.  Oh boy, fuel leak.  Ugh. 

[AquaNewbie]

Hi Boatnamesue,

Your description of how you use your boat is identical to how I will be using mine.

I thought the foam was saturated around my tank, but I took a 3/4" drill bit and drilled down into the foam at the aft end of the tank and water did not fill up the hole. 
So apparently the foam is not saturated! 

Since I am operating in fresh water perhaps this alum tank will last a long time.   I think I will not drill the drain holes, dry it out as much as possible and seal it up.
I have a new deck plate and fuel fill gauge coming to replace the old one.   I want to get these things in place so I can take this boat out and run it this year still. 

Any ideas on the best place to buy a replacement Teleflex steering cable ?

Dave

[theFunsmith]

The last place I bought a steering cable was on Amazon.com. I had it in two days and the price was better than anywhere else I found. I don't think they are sold under the teleflex name anymore though.

[AquaNewbie]

Teleflex - different name.   I saw that as well.   I guess I need to remove it and measure it.

Its amazing what you can buy on Amazon now. 

Dave

[JimInPB]

Teleflex cables work fine on motors that size & the design of the deck on that boat makes them easy to replace.  Hydraulic is nice, but its expensive.

I kept my fuel cell (coffin) intact, with no drain hole, because I don’t want to have gas get into my bilge (where my potentially-spark-generating electric bilge pump lives).  I open the top hatch on the fuel cell when the boat is not in use & let it air out.  That has worked for me so far.  I seal those with the fast dry version (24 hour cure) of 3M 4200, which gives a great seal, but is not easy to remove when you need to open things up again in the future.

65hp is about the minimum that you will want to have on that boat.  I would estimate MPG to vary from 1-6 with a 2-stroke that size, depending on conditions and how hard you hit the throttle.  Yes, the variation is really that much.  If you overload the boat &/or go against a current, MPG can even drop below 1. 

Congratulations on finding a 170 that is still in solid condition.  It’s a great little boat.

[AquaNewbie]

Well..... I figured out that the deck plate over the gauge on the tank on my 1974 170 Aquasport is a thin rim Bomar deck plate. 
I bought a thick rim Bomar deck plate and the clear plastic plug is a perfect replacement.   So I will keep the old outer frame and use the new plug. 

Bad news - whoever put the absorbent foam on top of the my gas tank, which was wet when I removed it, likely killed the gas tank.    I have a very small hole in the top of the tank where a spot of corrosion ate into the tank.       So I need to either repair this tank or get a new one.    I'm leaning to a new tank.   

I have repaired fuel tanks before via soldering but I suspect there may be some corrosion inside this tank as well.   Perhaps a new poly tank is the way to go. 

Any suggestions on where to get a tank?    I'll search this forum as obviously this is a frequent issue. 

Dave

[JimInPB]

If it's just a small hole at the top of the tank, with an obvious localized cause, I'd probably do a repair with one of the fuel tank epoxy products that is on the market.  It will probably buy you a few years. 

The original OEM that built tanks for Aquasport is still in business.  They moved from Florida to somewhere in Georgia, I think.  They will likely have the necessary information to build you a direct replacement tank.  Search around this site a little.  You should find their contact info & also a few posts from others who have already replaced tanks.  This site has lots of tips, tricks & other good information. 

[AquaNewbie]

That might be a good idea.   It does appear that there was something like a nut that was sitting on the tank in two different places that caused pits. 
So perhaps I am over-reacting.

I did drill a hole down behind the tank in the foam to check to see if water or fuel was standing in the foam and it is not.   So perhaps this hole is the only one.  I had better check out the rest of the top of the tank carefully. 

Perhaps I can kick this can down the road for a few more years.   I have some Fluid Film anti-corrosive that I could spray onto the tank that will stop any further corrosion.  I have been using that on cars for a few years now and it really works well.   It stops rust and doesn't easily wash off.

[boatnamesue]

Bad news - whoever put the absorbent foam on top of the my gas tank, which was wet when I removed it, likely killed the gas tank.    I have a very small hole in the top of the tank where a spot of corrosion ate into the tank.  So I need to either repair this tank or get a new one.    I'm leaning to a new tank.   

I have repaired fuel tanks before via soldering but I suspect there may be some corrosion inside this tank as well.   Perhaps a new poly tank is the way to go. 

Any suggestions on where to get a tank?    I'll search this forum as obviously this is a frequent issue. 

Dave

Foam is no bueno, unless it's laid in with no air pockets and no crevice between foam and tank...but good luck doing this.  So when I discovered my tank had a leak, I could visualize 2 small holes on the top of tank.  I didn't like the overall look of the tank, as it was caked with corrosion.  So I removed.  Turned out there was a total of 5 holes.  So my point is...you might only be seeing 1 hole, but there may be more.  And if there isn't more, since corrosion has already caused a hole, expect more to follow.

I have a '76 170, yours a '74 170.  I can't be certain, but I recon these two models have the same size fuel tank.  Perhaps Rickk or Capt. Bob will chime in to confirm this.  If the fuel coffins are the same, the fuel tank specs are 56 x 20 x 6 (28 gal).  Forget about the option of a poly tank because its not offered in this size (unless you want a poly custom made $$$$$$$).  I found an AL fabricator who built my tank for $400 and he included a wema sender.  Depending on where you live will depend on the number of fabricator options.

I did drill a hole down behind the tank in the foam to check to see if water or fuel was standing in the foam and it is not.   So perhaps this hole is the only one.  I had better check out the rest of the top of the tank carefully. 

Perhaps I can kick this can down the road for a few more years.   I have some Fluid Film anti-corrosive that I could spray onto the tank that will stop any further corrosion.  I have been using that on cars for a few years now and it really works well.   It stops rust and doesn't easily wash off.

I highly recommend you don't rely on "perhaps I can kick this can...." when it comes to a fuel tank and its potential to leak.  What I do suggest is removing the tank and pressure test it to confirm the only holes present are ones you know about.  It's a good idea anyway to remove all that wet foam.  And if the tank is good, or can be repaired, re-set using the modified pascoe method.  Details about this can be found here:  https://classicaquasport.com/smf/index.php?topic=14273.msg141575#msg141575