Using same gas tank for two motors

[iggyw1]

Hi guys,

I have what I hope is a simple question to be answered. I have a 70 h.p. Johnson and a 5 h.p Mercury kicker on my boat. I do not have room for the kicker gas tank where the tanks belong, so I was thinking about putting a "T" or a "Y" fitting in the gas line to the 70 h.p. motor and run a gas line off of this fitting to the kicker motor. they both use the same gas/oil ratio, so there would be no problem with that, and both motors would not be running at the same time, so the kicker should not rob the bigger motor of gas. Can I do this or not??
Thanks for your input! IGGY

 

[alldodge]

Hi guys,

I have what I hope is a simple question to be answered. I have a 70 h.p. Johnson and a 5 h.p Mercury kicker on my boat. I do not have room for the kicker gas tank where the tanks belong, so I was thinking about putting a "T" or a "Y" fitting in the gas line to the 70 h.p. motor and run a gas line off of this fitting to the kicker motor. they both use the same gas/oil ratio, so there would be no problem with that, and both motors would not be running at the same time, so the kicker should not rob the bigger motor of gas. Can I do this or not??
Thanks for your input! IGGY

Your going to need either a twin feed from the tank a fuel valve to switch between motors or check valves in line. You can pump up the fuel and start the motor but then the running engine will draw from the engines line not running. Easies way would be to put in a valve if your tank does not have an additional feed port

 

[GA_Boater]

I think it would be better to use a tank selection valve, or in your case, a motor selection valve. It's possible when either motor is running instead of sucking fuel from the tank, the path of least resistance will be through the non-running motor's fuel pump, carb(s) and crankcase, so the running motor will be getting air instead of fuel. Also if you rupture a fuel pump diaphragm, the same thing will happen.

EDIT - AllDodge types faster.

 

[iggyw1]

O.K. It makes sense to me. I was not thinking about those scenarios, but you guys are absolutely right. I'm going to try to find a 'Y' fitting with a valve on it to switch over from one motor to the other if such a fitting exists. Thanks!

 

[GA_Boater]

They exist - http://www.iboats.com/Moeller-Three...6891318--session_id.685033583--view_id.391858

 

[iggyw1]

They exist - http://www.iboats.com/Moeller-Three...6891318--**********.685033583--view_id.391858

Yep, this thing looks like it will work out great for my needs! I can hook this up between the two motors and run a gas line to each one of them with no problem with this. I'm going to order one of these and a few barbed fittings to screw into the valve and connect the hoses and I'm all set! Thanks very much!!

 

[Silvertip]

Just for the record, the opposite scenario applies when folks try to use two tanks to feed one engine using a "Y" fitting. Remember that fluids tend to equalize level. When the boat leans one way, fuel from one tank will flow to the low tank and possibly overflow. And unless the tanks are perfectly level all the time (that's not possible in a boat) that transfer of fuel will always occur. A tank selector valve is a must in that scenario as well.

 

[Don Hansen]

This is interesting. My Racor water separator/filter has 2 outlets on it. One goes to my 35 hp. The other to my 4 hp. I did not install any valves and they both start and run fine. Wonder if the Racor has one-way valves built in.

Don Hansen

 

[kbait]

If you use two primer bulbs (1 for each motor) downstream from where you tee'd from your tank, it'll work fine w/o isolator valve.if the check valves in the bulbs work.

 

[iggyw1]

I ordered the three way valve that was pictured above, and I should get it delivered on Wednesday 4-15-15 per my order confirmation from iboats. This will work out great for what I am trying to accomplish. Thanks to all of you for your input!

 

[Vic.S]

If you use two primer bulbs (1 for each motor) downstream from where you tee'd from your tank, it'll work fine w/o isolator valve.if the check valves in the bulbs work.

Even the valves in the fuel pumps should prevent the running motor pulling fuel or air through the pump of the non running engine.

Another possibility may be to fit a Johnson fuel connector to the Mercury, or a Mercury connector to the Johnson, and simply swap the fuel line from one to the other.