How to share a fuel line

[Sea Lion]

How to share a fuel line

Hi Gang,

     Always the best answers here.  I have just purchased an 8 hp Tohatsu.  I have an ancient but reliable 70 hp OMC engine.  It has oil injection so it uses straight gas.  I would like to t off the main fuel line but looking for suggestion on how to do this for my new four stroke.

 

 

Thanks,

 

Bob

[Willy-C]

https://www.westmarine.com/buy/moeller--3-8-fnpt-3-way-fuel-valve-brass--9398926

 

if you have any suction restriction from the tank, the large motor can produce too much vacuum and can hurt the kicker fuel pump if you only use a standard tee fitting. Pretty good price from WM too

 

I also have a Merc/Tohatsu 8 hp kicker, great motor

Edited April 23, 2017 by Willy-C

[pjprod]

i have a 150Hp Merc 4-stroke and have a 9.9 pro kicker. I used a fuel water separator... it will have one input and 2 outputs. Use check valves on each fuel line to the motors...A good squeeze ball valve has the check valves built in. I have had zero problems with this setup and works great!

[fisherdude]

3 way valve 

[Sk8man]

I have a 9.8 Tohatsu and have a direct injection Merc 135 Optimax and could go the route you are thinking but one of the main reasons for having the kicker is for emergency use. My thinking is although the t hook up is convenient.  I like the idea of separating my gas for each motor in case of contamination (e.g. moisture clogged line etc). of the big motor. This way in an emergency I can either runthe kicker (3.1 gal tank) OR hook it up to the big motor (I know.....I'm kinda anal)

Edited April 23, 2017 by Sk8man

[Frogger]

3 way tee. Have the same set up, after talking to an expert "Barretts", Fran said you won't have a problem with taking gas from the other motor, hooked it up like he said, haven't had a problem.


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[Sea Lion]

Like I said, always the best information on this site.  Thanks all of you for sharing. BTW, I am going to keep the 3 gallon tank on board as well just in case. 

 

Tight lines! 

 

Bob Lyons 

[fisherdude]

1 hour ago, Sea Lion said:

Like I said, always the best information on this site.  Thanks all of you for sharing. BTW, I am going to keep the 3 gallon tank on board as well just in case. 

 

Tight lines! 

 

Bob Lyons 

i am doing the same on my end also . Les ( sk8man ) has very good point 

[JAYRFRED]

When you "T" your fuel line, put a quality brass fuel shutoff in each line. When you run the main engine you can turn off the fuel line for the kicker. When you run the kicker you can turn off the fuel line for the main engine. This will guarantee that you will  not have one engine trying to pull fuel or possibly air from the other engine and creating a problem. It is also good when it's time to quit for the day. Turn the fuel off on the kicker and run it dry. This will ensure that you do not have a small quantity of gas in the float bowl to go rancid and cause staring issues next time.

Jay

Edited May 5, 2017 by JAYRFRED

[jimski2]

The fuel pump will suck air from the other motor fuel fitting and its air vent and you will have an engine shutdown. A tee fitting is not the way unless shut off valves can isolate each engines systems.

A separate small fuel tank for the kicker is a good set up.

 

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[Frogger]

Jim, although I probably would of agreed with you prior to hooking my system up, I felt somewhat lame after being given a set up that is just with a tee by a local marine professional that's been around for quite a bit. I have a 115 and a 8hp that has a 5/8 fuel line. After rigging it up, there is no such air being lost or fuel being sucked out of either motor. I actually can run both motors at the same time with no issues what so ever. I've never had to squeeze the bulbs when I stopped trolling and started the big motor. Maybe a misconception? I'm not arguing just explaining my setup. Tight lines


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[Frogger]

I forgot to mention, there is a squeeze bulb on each line to each motor after the tee. I have a spare 3 gal tank that can easily be clicked in if ever needed for emergency or in case of main tank issue.


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[fisherdude]

7 hours ago, Frogger said:

Jim, although I probably would of agreed with you prior to hooking my system up, I felt somewhat lame after being given a set up that is just with a tee by a local marine professional that's been around for quite a bit. I have a 115 and a 8hp that has a 5/8 fuel line. After rigging it up, there is no such air being lost or fuel being sucked out of either motor. I actually can run both motors at the same time with no issues what so ever. I've never had to squeeze the bulbs when I stopped trolling and started the big motor. Maybe a misconception? I'm not arguing just explaining my setup. Tight lines


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my buddy wanted me to hook up the fuel line in my boat with a 3 way tee about 3 weeks ago. i all most did ,   after asking about this topic in the winter I decided to go with the 3 way valve . i was going back and fourth in mind witch way to go . I PM L&M (Hank) and ask his opinion , he said if no valve or check valve in line serious damage can happen . now that being said if i ask Fran Barrett and he told me the same as he told Frogger i would have went that way too. I am not sure if it makes a difference if its outboard to out outboard or like what i have i/o to outboard . Any ways i went the 3 way valve and it is working just line , i do think i will miss not being able to run both motors at the same time if needed . 

Edited May 5, 2017 by fisherdude

[Sk8man]

If t were me I'd go with Hank's opinion.

[Frogger]

It's just like you Les to pin Hank on Fran lol.


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[Sk8man]

  They are both great

[jimski2]

My kicker would start up and then stall. A separate tank and line stopped this. Apparently the other engine connection would allow air into the system through the pin that opens the gasoline line. It opens the check valve and the air comes into the system through the vacuum from the small engines fuel pump.


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[muskiedreams]

My setup has been the same since 1996. I bought the boat used and the dealer added a new 15hp 4 stroke kicker on a bracket. The main motor is 2 stroke with oil injection. The fuel line has a T and I have squeeze bulbs on the hoses going to the motors. I have never had a problem. I squeeze the bulb on each motor before the first time of the trip I start each one. After that, I can switch between trolling and running as many times as I want. When trolling in the river, if I get a line snagged on bottom, I can start the main motor to bring the boat upstream (to hopefully release the snag) without stopping the kicker. I just put the kicker in neutral.

[steelhead strong]

Don't most squeeze bulbs have a check valve in them already? That would solve it..yes?....it wouldn't be able to backfeed

fish and visitors smell after 3 days

[jimski2]

The check valve at the bulb near the tank is not in line with the engine connection where the air comes into the system.


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[muskiedreams]

8 hours ago, jimski2 said:

The check valve at the bulb near the tank is not in line with the engine connection where the air comes into the system.


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Are you talking about using a portable tank and putting in a T after the squeeze bulb? If so that definitely will not work.

 

On a boat with a built in tank, you can put a T in the fuel line to split off to two separate lines which each have a bulb and the appropriate quick connector for each motor. Since each line has a bulb with a check valve, there should be no problem as long as the check valves are working properly. You can't do it if one motor requires pre-mixed gas and the other one doesn't.

Edited May 12, 2017 by muskiedreams