One Riggin' weekend...

Well, I've never put fuel in a Hydrodyne.

Below is a picture of my fuel tank (standing up on end in the lower box) and the install kit, including the fill hose and vent hose.

The fill hose seems pretty wide but then it narrows, of course, at the neck of the tank. I'm assuming that what happens is the fuel can feed into the hose faster than it can get through the neck of the tank, resulting in the fuel backing up and shutting off the pump or over-flowing all over the deck.

The tank is a plastic 18 gallon tempo or tempco, can't recall exactly. The dimensions seem to work perfectly for the opening, which is obviously why I bought it. I didn't see any metal tank options, although there might be some options out there. The original bow mounted fuel tank in my boat was removed at some point. I have no idea why.

I will most often be filling from a gas can. The siphon idea is a good one. What type of syphon do you use, Jim?

I'm not sure there's much that can be done with the filling problem, short of a tank with a wider fill neck.

I have noticed that the later Hydrodynes (later 70's) moved the fuel filler cap from the center of the deck above the tank to the side of the instrument bubble. This ostensibly was to make it easier to fuel the boat from the dock or with a gas pump. Of course, this location will result in less direct fuel flow when you fill the tank because the fill hose is now more horizontal with a couple of bends, rather than straight down to the tank, as is the case with the center deck mounting location.

I thought about moving my fuel filler cap to the side of the bubble (which is were the fuel vent is located on my boat) but decided to leave it in the middle. I left it in the middle because of my psychological need for symmetry, rather than for reasons of fuel flow. However, I suspect that, while I may have to reach further to get the fuel in, it may flow a bit better on mine because of the more direct route the fuel takes to get into the tank.

The rule in plumbing is that you can't increase volume by widening a pipe down-flow from a constricted diameter in the pipe. In other words, you can't go from 1/2 inch water pipe, then widen it to 3/4 inch pipe, and expect more volume. You'd need 3/4 inch pipe from the source to get the extra volume. Same with natural gas pipes.

What I am getting at is you would not be able to widen the filler hose that goes from the fuel cap to the tank and expect better flow because it will still back up at the same rate at the filler next.

Notwithstanding the foregoing, you CAN possibly improve things by making sure that your fuel tank is properly vented. This allows the air in the gas tank to quickly leave the tank as you fill it, which reduces back pressure in the fuel filler hose. Some newer tanks and gas caps are self venting through the fill how, which eliminates the need for a separate vent line. However, this may not work as well as an independent vent hose, which can carry more volume. You can see the fairly large diameter of my vent hose in the picture. It is the smaller of the two hoses pictured.

Having said all of this, I have no idea how well my tank will fill but I'll let you know soon...

MarkBano

 

On my boat, if I get the filler into the pipe on the tank it will sort of pressure feed the gas into the tank because it is a pretty tight fit. The trick is getting it past the end of the tank pipe. It wants to hang up there.

The siphon I use is a regular boat siphon with a ball check in a fitting that goes into the can. You put the plain end in the boat tank and the ball check fitting into the can. Then just shake it up and down to get the fuel flowing. My fill fitting is in the center of the deck and it looks good and works great. I put a towel on the deck to set the can on and then just siphon feed. The can may not fully empty, but it will be empty enough to fill direct.

jim

 

You might be able to take a knife and taper the inside of the tank pipe to make the filler nozzle go in easier.

jim

 

Here is the siphon and a gif to show how it works:

http://www.boatshowproducts.com/SuperSiphon.html?gclid=COi7zOW0w4wCFQV4VAodSXLObA

 

Mark,

I would still mount the tank in the bow in the middle. Too bad about the metal tank being gone.

Greg

 

P.S. Mounting plates look terrific. They look like they turned out well. Your entire transom looks great Mark. I think you will like using the sender on the back of the transom. I did.

Greg

 

Mark,

Did you decide to upgrade to the pop up cleats? Then you really do not have to worry about catching ropes on anything. Did you ended up getting any of those "oh shoot" handles for the inside of your boat from Overton's?

Greg

 

I reread my posts and they are not to clear about the problem. When I insert the gas station filler nozzle into the fill fitting, it does not want to go all the way into the tank neck unless it is exactly centered. Wiggling it back and forth will usually get it to go in. Getting up on the deck and looking down in the opening helps.

If you could counter sink or taper in inside of the tank neck pipe, then it would help the filler nozzle slide in. If you can get the filler nozzle into the tank neck then the nozzle trigger can be held wide open and fill the tank quick. If it is not in the tank neck, then it just dribbles in like RiverRat described.

My tank is shaped so that the tank neck pipe is pretty close to the deck so the filler nozzle can easily reach it. They may all not be like that, and they may not all have a straight shot at in.

jim

 

Jim

Thanks for the link. I'll take a look at the filler neck and see if there is anything I can do when installing it to make the nozzle fit better.

Greg - I'm not installing any cleats this year. I might install pop-ups next year. I bought standard cleats but decided not to install them after reading posts on this website. There are a number of things that won't get done for this season, like probably my plan for a carpeted rear bench/trunk, stereo, pop-up cleats.

I don't have the handle. Bob said I could have his extra handle but I'm not sure when I'll be able to hook up with him because he is pretty busy right now.

I can't get my depth sounder to work at all. I'm going to start a new thread on my guage problems...