Fuel line length/moving portable tank

[4barrel]

I have a older 14 ' runabout with 1971 johnson 50hp NO power trim.
Would lke to balance out front/back weight issues. Mainly all the weight is in back, 2 batt. spare jerry can and 22L plastic tank. and a transom mounted electric trolling motor.
Trims ok with me only and flys about 50-55km/h
But with extra riders and gear mostly center or back being a closed bow, takes forever to trim unless the 2 of us lean forward over windshield. LOL
Can I move the tank under the closed bow? Is there any issues with fumes blowing back at me? (vented on cap)
Do I need to get larger diam. line?
Is it ok to run the line that far?
Do I put the primer bulb near tank or motor? Would be nice to have it within reach of controls.
And I may plan to move a batt up there to (especially if I get Bow mount troller this winter)

 

[ondarvr]

Re: Fuel line length/moving portable tank

Just get the length of fuel line needed and have the bulb near the engine, then you can put the tank where ever you want. As long as the tank isn't mounted in an enclosed area you're fine.

 

[tmcalavy]

Re: Fuel line length/moving portable tank

From his description, it would be in a partially enclosed area...up under the bow, roughly in front of the pilot's and passenger's feet. Been pondering the same thing for my old tinny runabout...need to move the 15 gallons forward to balance the boat. Thought you were supposed to mount the bulb up by the tank, so you or the passenger can reach under the dash, grab the bulb and pump, pump, pump. Need to figure a way to put my tank on a sliding plywood platform, so I can still remove the tank/gas and use it on other boats...15 gallons gets mighty heavy.

 

[Johnny Too Bad]

Re: Fuel line length/moving portable tank

I actually just did the exact thing your asking about. I moved a six gallon fuel tank up under the closed bow storage area in my 1959 Texas Maid 14' aluminum runabout to help redistribute some weight.

I ran fuel lines from both tanks (one in the bow and one in the stern) to a three way valve that I mounted on the dash. Off the valve, I installed my primer bulb under the dash, so that it would be out of sight, but still accessible from the helm. Obviously, you would want your primer bulb on the return side of the valve. The return line from the bulb goes back to the motor.

Two things I've learned about this setup. One, it takes quite a bit of pumping if you run the tank completely out of gas before you switch tanks. And two, if you run the bow tank first, you will need to have someone vent the stern tank when you make the switch. I just run the stern tank first so that I don't have to leave the helm when I switch tanks.

I really like the way my setup turned out. No fumes and no other issues that I've encountered.

Hope this helps,
JTB

 

[tmcalavy]

Re: Fuel line length/moving portable tank

Oh yeah, I read that in your thread about your TM. I'm thinking of putting a 9 gallon and 6 gallon tank up front, and just switch to the 6 when I need to by moving the hose from tank to tank. I've got a riser, like a bench seat, forward of my feet under the bow, then a valley, then a bow/nose platform. Did you mount your forward tank on something and tie it down, or just lay it in there? My concern is loading the tanks forward after fueling without killing my back or shoulders...one surgery is enough, don't want another.

 

[Johnny Too Bad]

Re: Fuel line length/moving portable tank

I just set it in there. It's only six gallons, so it's not impossible, but when it's full it can be a little awkward to lift it up under there. I would imagine with a bum shoulder a 9 gallon tank would be pretty tough to manage. I really like your idea about a slide out platform.

 

[109jb]

Re: Fuel line length/moving portable tank

I'd move the batteries before I moved the fuel tanks. You said a 22L tank which is about 6 gallons. 6 Gallons of gas is about 36 pounds. A typical battery is going to be about 35 to 50 pounds. You said there were 2 batteries so that would be 70 to 100 pounds moving forward and you don't have to keep pulling them out all the time.

 

[Johnny Too Bad]

Re: Fuel line length/moving portable tank

I considered moving the battery up front, it just seemed like battery cable would probably be more expensive than fuel hose. Or is there a cheaper/easier way to hook it up from under the bow?

 

[tmcalavy]

Re: Fuel line length/moving portable tank

Fuel line is a lot cheaper than long battery/welding cable. I only run one battery and like having it in the stern close to the motor. I'll post pix if I come up with a swivel/roll-out platform for the tanks.

 

[4barrel]

Re: Fuel line length/moving portable tank

All very helpfull post to ponder,
Now just because these guys at AVO marine here helped me out I called them to ask about moving tank.
He says "It isn't recomended" Reason being is it is hard on the fuel pump, (this makes sense to me, and was kinda my main concern, with fumes blowing back being the second.
He said that no more than 8' is suggested with primer near tank or else it could prematurely kill a primer bulb to draw fuel that far. (meant to push not pull).
Don't think I'm beat yet!! I have a few electric fuel pumps somewhere.... wonder if that would take some stress off mechanical pump?
I will eventually move the spare batt to the front but, you guys are right about. Good power cable costing more than fuel line, even marine grade!
I don't really need to get at my batt. as much as I do the tank. And plan on rear bench over small homade livewell and cooler storage, This will make getting to the back by bilge more difficult don't want to struggle more than needed with tank, (like my uncles boat ) LOL!

 

[Lightnig]

Re: Fuel line length/moving portable tank

I have been kicking around this idea myself for down the road.

I think I have tentatively settled on (but will likely change my mind next week) to mount a permanent tank up front, add a proper fill cap on the bow (mine is also a closed bow), and then add in a low pressure electric inline fuel pump at the tank. Not only will the electric pump provide a means to prime the long line, it will also provide me an easy way to drain the tank should I need to.

And yes, along with a 'roll over' shutoff, I shall be adding proper ventilation since the tank/pump will be semi-enclosed.

 

[Johnny Too Bad]

Re: Fuel line length/moving portable tank

That's a good point about the extra distance taxing the fuel pump. I haven't experienced any problems with fuel delivery, but am now entertaining the idea of adding an inline fuel pump.

 

[tmcalavy]

Re: Fuel line length/moving portable tank

I've seen a stock OMC fuel pump on late 50's motors suck in the sides of a plastic fuel tank...so I'm not worred about taxing the fuel pump. Problem with permanent tank up front is how you gonna drain it to keep the gas from going skunky if you don't use it for awhile? Also, electric fuel pumps are not recommended...fumes or leak + electricity = boom.

 

[jaymasta]

Re: Fuel line length/moving portable tank

I've seen a stock OMC fuel pump on late 50's motors suck in the sides of a plastic fuel tank...so I'm not worred about taxing the fuel pump. Problem with permanent tank up front is how you gonna drain it to keep the gas from going skunky if you don't use it for awhile? Also, electric fuel pumps are not recommended...fumes or leak + electricity = boom.

I agree, my 1975 4hp johnson in not the best running condition, deformed my 12litre plastic fuel tank, and then started running rough it didn't even stall before I noticed it and opened the fuel vent.
For cheap heavy guage cable you can always find a set of jumper cables on sale, it usually works out to much cheaper then buying heavy guage cable, just cut the clamps off.

 

[tashasdaddy]

Re: Fuel line length/moving portable tank

the 27 gallon tank on my toon is under the console, 17 ft of 3/8 hose, no problems.

 

[tmcalavy]

Re: Fuel line length/moving portable tank

This weekend had a chance to try my idea of running two 57 OMC Big Twins off of one 9-gallon tank that I mounted on a wooden holder up under the bow skirt of my early 60's Texas Maid aluminum runabout. Ran a fuel line, with primer bulb, from the tank to a brass T and then fuel lines, with bulbs, to each motor from the T. Worked great. Waiting for a longer, one-piece length of fuel line to arrive from the Iboats store and I'll be all set. From motors to tank I figure is about 16 feet...or thereabouts.

 

[Mark42]

Re: Fuel line length/moving portable tank

I added a 14 gallon permanent tank under the bow of my 14 ft runabout. Here is the shareaproject link if you want to see and read about how I did it. And it really did a lot to help balance the boat.

http://shareaproject.com/pages/projectTut,p,78,00.html

 

[Johnny Too Bad]

Re: Fuel line length/moving portable tank

Hey TM, did you fabricate a slide-out platform for the tank? Post some pics if you get a chance.

Mark, that is exactly how I set mine up. I guess great minds think alike
The only difference is I don't have a permanent tank. It really makes a difference with the weight distribution, and I love the convenience of being able to switch tanks without having to leave the helm.

I used the same exact valve with street el's to a hose barb, although I put the quick connect on the other end of the hose and the Evinrude connection coming off the tank. I also pulled a little slack in the fuel line under the dash so that my bulb would be vertical. I originally had it mounted horizontally like yours, but it seemed to have a little trouble working properly. I think the check valve on the old bulb I had needed to be positioned vertically. I bought a new bulb and changed the orientation and now it works like a charm.

 

[tmcalavy]

Re: Fuel line length/moving portable tank

Well, I built and painted a plywood shelf/box/holder for my portable, plastic 9-gallon tank and screwed it down on the two shelves up under the bow skirt. The tank is long enough that it fits/loads easily when empty, but if it proves too heavy when full I'll cut a piece of plywood longer than the tank and strap the tank down to it, so the ply acts as a pull-out shelf/platform for the tank...that way I can pull the tank out, fill it in the boat and just slide it back in place and then lock it in place with a retainer strap. Meantime, I'm impatiently waiting for my longer piece of fuel line...none of the local shops around here had anything like marine fuel line, so it's on order.

 

[Johnny Too Bad]

Re: Fuel line length/moving portable tank

That sounds like it should work. Any thoughts of adding a permanent tank like Mark42 did? Check out his link if you haven't already. It turned out really good. Might be a good option to help save that bad shoulder.