Troubleshooting Fuel Line

mooseo

Seaman Apprentice
Joined
Apr 25, 2002
Messages
30
I'm looking for help troubleshooting my fuel line. I am getting some air into it somewhere.<br /><br />My setup is this: a 90hp johnson as my main motor and a 9hp auxillary motor. I run the fuel line from the tank to a Racor filter and then 2 lines come off of that (1 to each engine) each with its own priming bulb. <br /><br />When the main motor is running, if the kicker fuel line is plugged in (but the kicker is not running) air gets into the line. If I unplug the kicker, it used to be fine, but now I am getting air in all the time. <br /><br />The lines are showing some cracking and signs of wear, and the fitting to the fuel tank isn't as tight as it used to be. I will go ahead and replace all these bits, since that seems to be the recommendation on most of the posts I have seen. <br /><br />Do people think that new lines will solve the air in through the kicker problem, or is that something that I should have expected when I hooked them up that way?<br /><br />Also, I tried running a temporary line from my emergency tank directly to the main motor and the bulb stayed tight and I didn't get the air in. But this still didn't solve the basic motor problem. <br /><br />The motor is running rough, stalls, spits smoke... things that I have read in other people with fuel delivery problems. When I hooked up the new line, I stil got these same problems. Might there be some residual issues (too much oil in the cylinders, say) from it sucking air that will go away if I let it keep running rough, or do I need to look for other probelems?<br /><br />Thanks,<br />mike
 

pthein

Seaman Apprentice
Joined
Jan 4, 2002
Messages
45
Re: Troubleshooting Fuel Line

I would change the end where it plugs into the motor as well as all the fuel lines, new hose clamps (double if possible) and a new fuel filter. You might also want to change the motor side fitting where the fuel line plugs in as well. These connections are notorious for leaking.
 

MGuckin

Senior Chief Petty Officer
Joined
Jun 10, 2001
Messages
760
Re: Troubleshooting Fuel Line

I agree with pthein. Change everything. However, if you use hose clamps, be very carefull. Most of the fittings are plastic and will crack easy. That's why OMC uses a type of wire tie instead of a clamp.<br />Sounds like you may have more than 1 problem. Isolate and work on your main motor first. Make sure your filter is clean. Make sure bulb gets hard and stays that way. Excess oil from pre-mix should burn out or blow out after a bit.
 

mooseo

Seaman Apprentice
Joined
Apr 25, 2002
Messages
30
Re: Troubleshooting Fuel Line

When you say changing the end at the motor, do you mean the little plastic part that goes through the case? <br /><br />Thanks a lot for the warning about hose clamps... I'm sure I would have cranked it too hard. Any way to know how tight is right?
 

pthein

Seaman Apprentice
Joined
Jan 4, 2002
Messages
45
Re: Troubleshooting Fuel Line

the advantage to the plastic hose clamp is it is designed to clamp evenly around the entire circumference. If you look at a metal hose clamp you will notice an area under the screw that doesnt clamp evenly. As far as how tight - I have always tightened just until the clamp was slightly pulled into the rubber but not bulging around the edges.
 

Bear

Lieutenant Commander
Joined
Mar 1, 2001
Messages
1,627
Re: Troubleshooting Fuel Line

You'll need a three way fuel tap. The running engine will draw fuel from the other engines floatbowl until it is dry. Then it will suck air. <br /><br />/Bear
 

oldboat1

Fleet Admiral
Joined
Apr 3, 2002
Messages
9,607
Re: Troubleshooting Fuel Line

As to the running problems with the kicker, it's an old song but I suggest using fresh gas and oil as a first step. I think you referred to use of a reserve tank -- I'm thinking that might be stale gas. <br /><br />If you have the room, it might be preferable to run the auxiliary off its own tank. That way you can take care of the other fuel delivery problems, as well as better insure that the gas for the kicker will be fresh.
 

russthemuss

Petty Officer 2nd Class
Joined
Jan 16, 2002
Messages
101
Re: Troubleshooting Fuel Line

Hi Mooseo,<br />If your running one of those Racor filters that has the water trap on the bottem then the filter above,then the housing, and the bolt thru the middle.THROW IT OUT. (buy the new style) I have replaced more of these in the marine industry then i can count!!!
 
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