On board gas tank question

[onstumplake]

Hello, I'm new to the forum and this is my first post. Hello everyone!
Post: As my father-in-law has been unable to use his boat for about 5 years, because of health issues, it's been sitting in his garage all that time. I recently brought it home to try and get it going and either sell it or use it. I'm not sure of the exact model but it's a 1990 164 Side Console Deluxe. I think. 7' beam, and deep. It has a 70 Evinrude.
So, I thought it best to drain all the old gas to start things off but have been unsuccessful so far doing so. It has an on-board tank with a line coming up near the rear and then to the engine with the primer bulb in between. The bulb seems fine as does the line itself, at least the part I can see. I cannot get any gas movement by squeezing the bulb, seems line only air is available in the line. I cut off the hose right by the engine fitting so I could drape the line down to a bucket. But no-go no gas moves.
Since I really could not hear any gas sloshing around in the tank, I added about 2.5 gallons and tried again. But nothing. Now what? I can't really follow the gas line further into the boat without taking things apart but don't know where to start since I don't know where the tank is either. The fill spout thing is on left side top, a bit over half way up the boat. Any suggestions here? Thank you.

 

[Scott Danforth]

welcome aboard.

you will need to find out if your father ran the tank completely dry or did all the gasoline turn to varnish/sludge and you need to clean the tank

to clean the tank, you need to find the access cover over the fuel tank sending unit. remove the fuel sending unit and look into the tank.

 

[onstumplake]

Thanks Scott.
I highly doubt my father-in-law ran the tank empty. Unfortunately, his medical issue is dementia, so he knows nothing about the boat anymore.
If anyone can provide clues as to where I can find that access cover, please let me know. Or if it would help if I sent some various pics of the boat?
Thank you, Larry

 

[CaptnKingfisher]

I'm sorry to hear about your father's condition. I'm not familiar with your specific boat but if I was approaching it to drain the tank I would start by carefully tracing the fuel line from the engine to the tank (as far as I can) This should allow you to verify that there isn't a shutoff valve installed or a tank selector switch in (case your boat has two tanks). Following the fuel lines and the fuel fill lines should also give you a general idea of where the tank(s) are located and you can start looking around that area for access.

Pics might help. I have drained fuel tanks on several boats and cars and I like to keep a small electric fuel pump in my tool box for this purpose. I have battery clamps and a switch wired to it so I just hook it up to the boat battery, hook up the fuel line from the tank and a spare piece of 5/16" fuel line into my waste Jerry can and flip the switch. I could take pics of my setup if it would help. But you should be able to manually pump it out with the primer ball if things are set up right

 

[Scott Danforth]

Thanks Scott.
I highly doubt my father-in-law ran the tank empty. Unfortunately, his medical issue is dementia, so he knows nothing about the boat anymore.
If anyone can provide clues as to where I can find that access cover, please let me know. Or if it would help if I sent some various pics of the boat?
Thank you, Larry

its an aluminum boat. start by following the line. because its aluminum, they may have assumed the floor itself is a good enough hatch

the fuel tank will be under the floor, most likely in the center of the boat, just aft of the helm seats.

 

[onstumplake]

Thanks guys for the replies. My plan for this weekend was to take rear side panels off so I could remove rear floor panel(s). Neither of which are fun since I've removed all panels for rot and carpet replacement on a boat I had years back, but that's another story which ended well.
Anyway, even though I believed I had poured enough gas in tank (assuming it might have been empty) to be able to have it come out primer bulb hose, I decided that before taking things apart, I'd tip up boat/trailer a bit higher in the front, quite a bit higher. Did that and lo and behold I had gas coming with just a couple squeezes of the bulb. Geez, should have done this sooner but things seem more promising now.
So now my weekend plan is to try and actually get the motor running with some Sea-Foam enriched gas. Wish me luck on this since we all know how carbs can be from the boat sitting for a number of years. Thanks again!
Larry