Fuel Tank Hose Routing

[capt_nemo]

What is the best way to route the fuel hose from the tank in the transom cubby to the motor on the OB Bracket?

[Tom Ray]

Is this a trick question, Don? There's a conveniently located little hole with a flapper on it that leads right into the fuel locker.

The problem I have had is that the downstream (engine) end of the primer bulb is supposed to be pointing up, and it can act as a check valve and prevent fuel flow if pointed down. I loop it around a bit to keep it pointed up as best I can. Joe has a little bungee for the purpose on his boat.

[ontarioSuncat]

I shortened my fuel line so the bulb is closer to the engine. The factory length had it drgging in the water and way to low to reach with ease. Now it is only a foot from the engine. Because sailing a Suncat is supposed to be easy.

[capt_nemo]

Tom,

No, I'm quite serious. I knew about the hole in the transom with flapper valve.

I recently purchased a new fuel hose, made of material which supposedly is impervious to ETHANOL, with the bulb and fittings permanently crimped on. I have yet to try getting the engine end thru the hole (not high on my priority list) but it may not fit. I'll check it soon, and if necessary will cut, splice, and use SS hose clamps to remedy the situation. I was looking for any negative experiences/comments about such routing or perhaps even some other imaginative way of routing that is more advantageous.

Your heads up comment with regard to primer bulb orientation was right on the money. Thanks!

[brackish]

Tom Ray said:

The problem I have had is that the downstream (engine) end of the primer bulb is supposed to be pointing up, and it can act as a check valve and prevent fuel flow if pointed down.

I didn't know that.  I have two tanks and hoses.  One of them has the bulb outside the transom close to the motor, the other has the bulb inside the fuel locker area (CP23),  The first mentioned does fine, but the motor sometimes seems to surge then drop back when using the other tank like it is temporarily starved of fuel.  Never could figure out why.  Maybe that's it.  I'll have to check the bulb orientation the next time I use the surging tank.  Thanks for the tip.  It is worthwhile to check up on this catboat stuff.

[Tom Ray]

Brackish, that is likely your problem. There are other possibilities, but it sounds right.

The bulb will make an imperfect check valve most of the time, allowing some fuel through, so you'll get a motor that just mysteriously fades and sometimes dies.

Don, instead of stainless hose clamps, I have started making my own little hose clamps using one of these.



I have one of the ones on the left, usable with small stainless wire sizes. It makes an almost perfectly flush clamp, and if you tuck the ends carefully there are no sharp edges anywhere. The resulting clamp has no moving parts and is pretty indestructible. If something bad happens to one, get the spool of wire and make a new one.

I used it to lash PVC pieces to my golf cart as rod holders, among other uses. The website shows it being used to bind a splice, and there are stories somewhere of someone using one of the big ones and some big wire to splice a mast! They are now required for some offshore races. Pretty versatile tool. Any size hose clamp, including irregular sizes, or wire anything to anything else very tightly.

[ontarioSuncat]

YOu don't put the engine end through the transom hole, you feed from the outside and feed the tank end into the fuel locker.

[capt_nemo]

I finally went to the boat and tried to get an end fitting (both are identical) into the hole with flapper leading into the fuel tank cubby. And, just as I suspected, the crimped on fitting would not go into the hole! Needed about 1/8 " more inside diameter to fit.

Don't know if there's an industry standard on exterior dimensions for outboard engine fuel line fittings or if they differ from one manufacturer to another. Makes me wonder which one Com-Pac Yachts used when designing to make sure one would fit through, or did they simply assume that a ready-made line would be disassembled and reassembled when routed thru the hole.

Oh well, nobody said that PROPERLY rigging and outfitting a SunCat would be easy. As both a longtime Sailor and Engineer, I'm glad I thrive on meeting challenges!

[brackish]

Brackish, that is likely your problem. There are other possibilities, but it sounds right.

The bulb will make an imperfect check valve most of the time, allowing some fuel through, so you'll get a motor that just mysteriously fades and sometimes dies.

The other differences between the two are that the offending tank is self venting (what does that mean?) i.e. it does not have a manual vent to open, and it has a 3/8"diameter hose while the tank that seems to work well has a 5/16" hose.   Not sure why either of those differences would be a cause.

[capt_nemo]

Brackish,
However the "self venting" tank is open to ambient air, make sure it isn't clogged or blocked. If not evident you might want to ask the manufacturer how it works. If you do find out please share it with us.

[cavie]

1/8" larger opening??? Me thinks 1/16" shaved of 2 sides of the fitting should cure the problem. My squeeze ball is in the locker with absolutely no excess hanging outside. Just enough to get to the motor.

[Tom Ray]

I'm unimpressed with "self venting" fuel cans (the kind used to carry fuel) because they vent backward through the flow of fuel, slowing it down. I'm holding onto my old fashioned ones with the little yellow flip vent.

I imagine a "self venting" outboard fuel tank has to do the same kind of thing. The air has to come from somewhere, and if the only hole in the tank is the one that lets out fuel, that must also be the one that lets in air. Another bad idea, IMO, if that is the case.

I love my Scag lawnmower. The fuel tanks have HUGE caps set and angled outside of the machine a bit. Remove the spout entirely and GUSH away like a NASCAR crewman! #%*@&*$# fuel spouts! Hate 'em! Way to go, Scag!

[brackish]

This is the tank.  http://suncoastmarineoil.com/6gallonportablefueltank.aspx

I bought it because it is one of the only 6 gallon poly's that will fit in the 23 fuel locker area.  I have no idea how the venting works.  It surged from day one when brand new so I doubt that anything is clogged.  The motor has never stalled, it just seems to go up and down in RPM in a relatively narrow range which does not happen with the other tank.  Going to try the bulb orientation first, see if that might be the cause.

With regard to getting the fuel line through the tube, the catboat must have a smaller tube than the 23.  I can get the hose fitting through with the elec. start cable already in there.  In fact, I made a quick disconnect on the power cable so I wouldn't have to remove it from the battery every time I removed the motor and deal with fifteen feet of cable.  I did have to shave the corners of the disconnect below to get it through the tube.  I think the tube is 1-1/4" ID on the 23.  BTW this disconnect works great.  I planned to initially use a trolling motor disconnect, but it would not fit through the tube.  This will and only 8 bucks.

http://www.powerwerx.com/anderson-powerpoles/powerpole-sets/pp75-red-black-75-amp.html

[bfelton]

I have the same problem.  What you need to do is this:

1.  replace the fitting on the tank with a quick release fitting

2.  cut the end off the hose and connect the other half of the quick release.

Now the fuel hose will go through the existing hole in the transom.

Bert Felton

[Salty19]

Here are those quick release fittings Bert suggested.

http://www.motionpro.com/motorcycle/tools/category/quick_disconnect_couplings/

I've used them for dirt bikes in the past...they work well.