Off Topic Fuel Issue

hvyhaul

hvyhaul

Well-Known Member
Ever since my son and I acquired our boat, the kicker has had a habit of sucking air into the system over time, and then eventually stalling out.

Remembering to, or trying to remember to give the bulbs a squeeze periodically works but, at times we go too long and, stall.

Replaced all the bad clamps, lines still appear good, installed a water separator, this Spring, and thought I might have beaten it, but yesterday it was a nuisance again.

I've purchased a brass fuel shut off to put into the 115's supply as I am thinking the air might be coming from the 115's fuel screen at the motor.

There is no leakage, anywhere but that's my conclusion.

Suggestions, recommendations?
 
I had the same issue with my 15hp johnson and it was the fuel line connector that clips onto the motor, there is an oring on the inside that tends to crack/breakdown and suck air bought a new one for 10 bucks and never had an issue since. I now keep one as a spare on the boat just in case because my main motor has the same connector.
Hope this helps @hvyhaul
 
Are you sure it's sucking air or creating a vacuum that cuts off fuel? If so then there's a restriction somewhere maybe in the lines themselves.
 
I hadn't thought about creating a vacuum.

The bulbs go completely MT but not collapsed and prime up as I think they should.

The 115 runs fine and it doesn't do what the kicker does. Yamaha motors both.
 
[QUOTE="hvyhaul, post: 158030, member: 6039"The bulbs go completely MT but not collapsed and prime up as I think they should.[/QUOTE]

What exactly do you mean by MT? The only thing that comes to mind is the abbreviation for Montana. :)

Is the fuel line connected to the one for the 115? Separate bulb for the kicker? I found Yamaha makes great primer bulbs which seldom ever lose prime even after weeks of non-use. Hard to tell if that's your problem but the few times I had an issue like your describing it was always the bulb, especially if old creating a vacuum then loss of fuel. Sometimes they will prime back up but continue to lose it some time later. Not an expensive fix to try if all else fails.
 
Check the spark plugs. See that the gap is proper. If thats good check fuel hose with primer bulb. Inside Could be coated/pinned with a heavy shellac like residue,will cause insufficient fuel delivery. If that's good try the idle mixture screw. You have to turn it in or out. With motor running Turn in 1/8 turn at a time wait a couple seconds and listen. Will start stumble when it gets to lean. Same when turning out. 1/8 turn at a time wait&listen. Will start to miss and shack when to rich.
 
MT = empty

Sorry use it all the time at work.

Separate fuel lines from separator, both have primers replaced since purchase.
 
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This problem is quite common. Same thing happend to my boat when I got my kicker on this spring. At first I thought I would need to have a separate fuel tank just because the 300 is usually quite thirsty. I decided I would be alright but the day after they put it on and I took it out, it started to cough and stall. There was air in the fuel lines. Not sure how they fixed it but it’s all over the internet.
 
@SIX-GRAND , the plugs have 5 trips on Erie, I replace them each fall. Issue is from purchase, I just put up with it until now.

The motor itself runs great (save the starve) so I don't think I'll play with the carbs just yet.

I will likely replace the fuel lines and insert the shut off into the 115 supply line. Both bulbs have already been replaced with OEM level bulbs so I hope one of them hasn't already gone bad.

@Matt245 , true, the problem is all over the internet, unfortunately, the answers are all over the map.

I did bleed the air from the system when I installed the water separator, initially appeared to correct the issue, but it has returned.

I'll work the solution from simple to complex and hopefully by my week's holiday later this month, have it solved.

Again, thanks all.
 
hvyhaul said:
Ever since my son and I acquired our boat, the kicker has had a habit of sucking air into the system over time, and then eventually stalling out.

Remembering to, or trying to remember to give the bulbs a squeeze periodically works but, at times we go too long and, stall.

Replaced all the bad clamps, lines still appear good, installed a water separator, this Spring, and thought I might have beaten it, but yesterday it was a nuisance again.

I've purchased a brass fuel shut off to put into the 115's supply as I am thinking the air might be coming from the 115's fuel screen at the motor.

There is no leakage, anywhere but that's my conclusion.

Suggestions, recommendations?
Click to expand...
I also had this problem. I installed a valve on the kicker side and shut it off when I run my 90hp. Havnt had an issue since. Also try replacing yiur prime ball. There could be an issue with the check valve inside.
 
Fuel line is cheap. Run all new lines with proper clamps (not zip ties) and replace the fuel fittings as others have suggested. Check your pump and seals in your carb but it sounds like the problem is on the low pressure side.
 
Simple shut offs on each fuel line may help. Only turn the fuel supply on to the engine being used. I had an onboard in the last that did not like to share fuel with the kicker. It would run fine for a while (until it sucked all the fuel from the line then would stall out). I installed to brass shit offs and never had a problem after. It’s a shit show when your trolling into the waves with 6 or 8 lines out and you lose power. I wouldn’t be ripping into carbs until your certain your fuel supply is sound. Try running it on a separate gas can for a trip. If it behaves it must be a supply issue. If it still acts up then you could be more certain you have a delivery issue.
 
Like @noclass suggested. Grab a 10L fuel cell and run it completely seperate for a couple trips. Or even throw it in a garbage can for a few hours. Easy and cheap trouble shooting.
 
It gets very chaotic onboard when the kicker starts to shudder. LOL But we all have learned the drill.

Five lines on Saturday and not a single tangle.

I'm just tired of it.

Picking up ines tomorrow after work and will redo them and install the shutoff on the 115 line.

The 115 has never skipped a beat cruising, waterskiing etc, etc, so I figure that is the side that is allowing air to enter the system when the kicker is running for long periods of time.

If that doesn't fix it, I will continue following my hunches and the suggestions provided until successful.
 
Might be a simpler fix than feared, a missing clamp at fuel pump, and 2 nylon ties at fuel screen.

fuellines.gif

I'm still going to redo the lines and make sure all fittings are properly clamped.
 
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hvyhaul said:
@SIX-GRAND , the plugs have 5 trips on Erie, I replace them each fall. Issue is from purchase, I just put up with it until now.

The motor itself runs great (save the starve) so I don't think I'll play with the carbs just yet.

I will likely replace the fuel lines and insert the shut off into the 115 supply line. Both bulbs have already been replaced with OEM level bulbs so I hope one of them hasn't already gone bad.

@Matt245 , true, the problem is all over the internet, unfortunately, the answers are all over the map.

I did bleed the air from the system when I installed the water separator, initially appeared to correct the issue, but it has returneI'll work the solution from simple to complex and hopefully by my week's holiday later this month, have it solved.

Again, thanks all.
Click to expand...

Did you by chance put a new Atwood primer ball and line on?
I just went through an ordeal with fuel issues on my main motor.
My brand new Atwood primer ball was causing 4" of vacuum.
Changed my primer ball and retested on a water Dyno and it didn't drop below 1/2" of vacuum under full load on dyno

Just a thought...
Also check pick up screen on tank if it has one isn't getting clogged
 
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