Problem with hooking kicker to main fuel tank!

[rshubuck]

I have a 2003 yamaha 15hp 4stroke that I am trying to tie into my main fuel tank. After a long staking process of elimination I directly hooked the 6' 3/8 fuel line to the main port of the main 61gal fuel tank. After pumping the bulb again the motor would not stay running if I did not continue to pump fuel to it. Now I did take a 5 gallon fuel tank at put the hose into the tank and it ran fine. I then took the port off the main fuel tank and placed it into the 5 gallon fuel tank and it ran for sometime boat slowly died. The intake port to the main fuel tank is about a half an inch wide. It just seems that the motor has reached its pumping compacity.

Im just not sure what to do at this point. Smaller diameter hose, new fuel pump or something else? Please help!

[rolmops]

There must be air entering into your line at some point,which I think is the connection to your main tank.It may be aggravated by the the height difference between the engine carburetor and the fuel tank.

Make sure that there is absolutely no air coming into the system and make sure that you have a check valve near the main tank.

If you connected your 3/8 line combined with the main engine then there may be air coming from the other engine and that may cause trouble. This can be solved by using a three way valve which usually works better than a check valve.

[rshubuck]

As of right now I have my main engine disconnected from my gas tank and have the kicker motor connected to the gas tank instead. I have a brand new fuel line and I still can't get it to pump fuel with out me pumping the bulb. I checked every seal and it all seems to be great but just not working.

[borderline 350]

Dear RSHUBUCK,

Remove the fitting from the elbow in top of the tank. (It has a spring loaded checkball in it) Install a tee with two shutoff valves and barbed nipples for each line. The OB engine should run fine with 6 ft. of hose. YOU MUST INSTALL shutoff valves to meet USCG, BIA & insurance co. requirements...A MUST!!!!

The OB fuel pump does not have sufficient vacuum to keep the checkball open. Common problem on these installs. You may also have vacuum leaks in your OB fuel line...Check very carefully......

Respectfully submitted....Jet Boat Bill

[Mickey Finn]

How's the fuel pump on your motor? I've had problems before on larger motors not being able to pull enough fuel and I just rebuilt the fuel pump and that cured it. I have an 8 hp Honda and it pulls fuel fine from my main tank which has the check valve and I'm also pulling it through a fuel/water seperator. Also, check the end of your pickup tube. They usually have a screen in the bottom of them and that could be plugged.

[emtystringer]

iI HAD A PROBLEM WITH AIR BEING SUCKED INTO MY FUEL LINE THOUGH THE OTER MOTOR.MY REMEDY WAS I RAN ONE LINE FROM MY MAIN FUEL TANK TO MY WATER SEPERATOR,I THEN ADDED TWO SEPERATE (OPEN -CLOSED) VALVES, ONE TO TROLLING MOTOR AND ONE TO MAIN MOTOR.I KEEP THE MOTOR THATS NOT BEING USED CLOSED. GOOD LUCK

[rshubuck]

The other thing I failed to mention is that I did take the check valve off and put a barbed end on. It too did not work. I guess at this point I'm going to travel to some Yamaha service center today and ask for their opinions

[jimski2]

Try running the kicker on a portable tank to eliminate the fuel line questions.

[Mickey Finn]

The other thing I failed to mention is that I did take the check valve off and put a barbed end on. It too did not work. I guess at this point I'm going to travel to some Yamaha service center today and ask for their opinions

So you replaced the check valve with a barbed end and connected your 6 foot hose directly from the tank to the motor and it didn't work? It shouldn't have any problem pulling fuel that far. Not sure what that motor has for a fuel pump but I'd ask the Yamaha guys about rebuilding it. Probably just some gaskets and a diaphragm. Also, have you checked to make sure that the vent line for your tank isn't plugged?

[rshubuck]

Yes. I opened my the gas cap also to make sure it was not it. I'm heading home now to directly connect the fuel line to the fuel pump on the kicker to eliminate any restrictions from the male and female connections. No one Has a fuel pump in stock or I would replace it. The fuel pump does look good though

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[rshubuck]

Just An update. I hooked the fuel line directly to the fuel pump. Also replaced the bulb and fuel line to 5/16th. There was no chAnge. If i put the the 5 gal tank high it worked fine, but if I put the tank on the ground it would quit pretty Quick! I noticed the piss port water discharge wAs a rainbow color on the ground. I think it is my fuel pump. There must be a hole in the diaphragm and fuel is leaking through it into the water cooling chamber. that's my guess. So I ordered one and have my fingers crossed!

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[lakebound88]

Robert, I have my yamaha 9.9 high thrust plumed into my fuel/water separator.. It has 2 inlets and 2 outlets off the housing and i have no issues. I even have 8 foot of OB line. Does your main motor have a fuel/water separator? If so, check the ports... Try that, and see if it helps..Plus with this ethanol, that filter will help too!!!

[rshubuck]

Thanks Nick.

When I bought the kicker I went and purchased the water seperator so I could use the ports and that is how I hooked it up to start, but the kicker would not say running. So then I disconnected my main motor from the gas tank and directly hooked it to the gas tank to eliminate an issue of it sucking air from the big motor(if that was the problem) and it still would not stay running. Thats when we got the 5 gal fuel tank out and I put it above the motor and she ran fine and had no problem with pumping fuel but as soon as I put the gas tank on the ground she would soon quit. I'm positive the fuel pump is bad at least thats what I am hoping. So I ordered a new fuel pump for $70 plus shipping and it should be here wed. As soon as I get it I will let everyone know how I make out and post some pictures. I'm also waiting on to get my Lowrance hds 7 back from Lowrance Support.

[Tripleduece50]

Yeah probably the fuel pump I run a 9.9 yamaha from my main tank with no problems. One thing I read was to mount your squeeze primer bulb vertical so the check valve in it works to its full potential. My fuel line has to be at least 8 foot or so with no probs.

TD

[rshubuck]

I thought I would let you guys know how I made out. I got the part last Saturday but had to work plus it was a different part. I got back online and the schematics said it was the right part. Red flags were just jumping in my head. The old part in the picture as you can see has 3 ports. An in, out and the pulsator line. The new part only had an in and out port but had a plastic spacer that was cut to perfectly fit in the groves of the power head. Also the pumping mechanism was designed to go in to the motor. I took the old pump off and sure enough it had a flat back on it and the there was a home custom gasket cut to cover the hole in the motor. My best guess is this pump failed and they just replaced in with a snowmobile fuel pump or something for some stupid reason. I had to get longer metric thread bolts to accommodate the new fuel pump. I hooked it up to my main gas tank by itself and immediately I could tell it was working when I started the motor The fuel pump was pulling fuel out of the tank no problem. I did not get a chance to hook up my big motor again and put it all back on the water separator because a storm system moved through but I should have it finished today and have a bunch of other addition on the boat today. I will post pics on another topic!

The old fuelpump

[windburn]

How'd that alternator/regulator kit job go? I've been keeping a close eye on my old water cooled regulator. I clean ALL terminals at the start of every season but will go the alternator kit at first sign of failure. I think it's the better cost effective option.

[rshubuck]

It work out great. I only had it out once since I put it on. Half hour install and I wa back in business. I will post a pic soon as I get all this stuff put on. Another storm system just moved in:(

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[Mickey Finn]

Great. Sounds like you got it.