Mounting a kicker motor to run off the main fuel line

[JerseyJim]

I have a 15hp johnson that could easily be mounted on my 22' aquasport as a trolling motor / get home kicker right on the transom. My fuel tank is pre-mix, so fuel to the big motor and to the small motor would be the same. <br /><br />On the transom I have a fuel water separator for the main engine, which is a 200hp merc. In theory, I should be able to pick up a fuel hose for a johnson, cut the hose after the bulb, and just clamp it on to the fuel water separator.<br /><br />Here are my questions:<br /><br />Would there be any complications with me just putting another brass fitting into the 'out' line on the fuel/water separator (currently it's plugged with a brass 'plug') and running that to the kicker motor? <br /><br />What could I do when I want to remove the johnson and put it back on my whaler, would I have to remove the brass fitting for the fuel line and put the brass plug back in it?<br /><br />Would the johnson fuel pump be strong enough to suck the fuel through almost 18' of fuel lines and a big fuel water separator (made for mercury engines no less, not johnsons)?

 

[Bushleaguer]

Re: Mounting a kicker motor to run off the main fuel line

Jim-<br /><br />I have the same boat- how do you like it? I'm a little underpowered with a 115 Evinrude, but I really love the boat. Mine has a port and a starboard hose barb to supply fuel lines for twins. Do you have them as well? Could you run your kicker off the other one if you do? One other thing you might check- I was going to do the same thing as you, but with my 9.9 HP Johnson. The "clamp" on that motor was not wide enough to slide down over the transom. I ended up scrapping the idea, rather than starting to grind on the transom or the clamp, or trying to modify the bolts that tighten the motor to the transom. You might want to check our whether the motor fits. My boat is a 1987. Maybe if yours is a different vintage, it might fit. Good luck!

 

[JerseyJim]

Re: Mounting a kicker motor to run off the main fuel line

Mine is a '72, so in all possibility your rigging is different. My fuel tank is under the center console and stretches to under the reversible pilot seat., and I only have a single fuel line coming out of it (that's not to say there isnt a second barb down there). My fuel line runs up the wiring channel / tunnel (accessable via removing 16 screws and the whole 10 foot access cover comes right off) on the starboard side and pops out in the stern. <br /><br />The boat so far I like it a lot, as it has handled the chop well, and it has a LOT of power. At 3000rpm I averaged about 20mph, and at 3500 about 28-29mph.. WOT so far is 38mph at 4800 RPM (boat is possibly underpropped). The previous owner said he had it up to 50mph WOT on a real calm day - i have yet to see that kind of speed.

 

[Fouled Plug]

Re: Mounting a kicker motor to run off the main fuel line

Your kicker should pull fuel fine through that setup. I would suggest a small length of fuel hose off of the seperator with a male end compatible with your kicker line. That way you wouldn't have to cut the Johnson's fuel hose, and it could be transferred from boat to boat. Just a thought.

 

[DJ]

Re: Mounting a kicker motor to run off the main fuel line

Jim,<br /><br />Yes, you can do what you are describing. <br /><br />However, why not buy another fuel line assembly for use on your small boat and leave the aux. hook up in the big boat. We're talking $25.00 here.<br /><br />Words of caution. <br /><br />I would put a marine approved fuel shut off valve on the outlet of the seperator to the aux. engine. The valve should be turned off when running the big engine. You do not want to run the risk of sucking air from that second fuel port for the aux. engine.

 

[JerseyJim]

Re: Mounting a kicker motor to run off the main fuel line

djohns: Thanks for the great idea - I wasn't worried about buying another hose - hell that's just 20$ who gives a hoot... <br /><br />I will get another brass fitting, another hose, and a shut off valve. I was worried about the big motor sucking on the other line, but that can be fixed with a simple **** off valve. <br /><br />Fouled plug: I will look into that as well, just getting a connector that will mate right into the existing hose, no cutting involved... I *DO* however like the idea of a shutoff valve, though. With the valve, I can just close it off and not have to worry about another hose or the big motor sucking in air through the open fitting.<br /><br />Excellent!

 

[Bear]

Re: Mounting a kicker motor to run off the main fuel line

I belive that the running engine will draw the fuel from the other engines float bowl until it is dry. Then it will suck air. You will have two engines with totally dry carbs and they will be hard to start again. <br />The marine approved fuel shut off valve djohns19 talked about will cure that. So go for it.<br /><br />Edit: Yes I'm typing slow again

 

[45_red]

Re: Mounting a kicker motor to run off the main fuel line

You've gotten some good tips on running your kicker off the main tank, but you might want to use a seperate tank. Most on-the water power problems are fuel problems and having a seperate tank has been a real benefit to me.