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2013 Yamaha F40 LEHA - Fuel / Fire / Air?????

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Duane Mercer 21

New member
I have a 2013 F40 LEHA Yamaha Outboard that’s causing me major grief.<br>
It will run flawlessly for 15-20 minutes then it appears to lose its gas and completely shut down. It will start right back up instantly but will only run at idle. Could it be going into limp mode after it really heats up after 15 minutes or so? <br>
Had it into the local Yamaha Dealer and they said there were no error codes and no issues when they water tested it. Fuel pressure was good, intakes were good, everything seemed fine, they installed new plugs and said do use it....... Motor has less than 190 hours on it. <br>
I think the dealer just didn’t run it long enough for it to do it’s thing? <br>
I have a video of it doing its thing - where it just won’t take any fuel, it spits and sputters when you try and give it throttle but it will idle with zero issues all day long? It’s got to be fuel related doesn't it? Maybe the high speed pump quits after it gets hot? Or could it be fire related, or air? <br>
When I leave it overnight and it cools down it will work great again for another 15-20 minutes…….<br>
If I can figure out how to add the video I'll do so. But I'm having trouble figuring it out......<br>
Anyone seen this before or have some ideas as to what is going on? Appreciate any help I could get.
 
I believe your problem may be that the vapour separator tank (VST) is not getting fuel. I had a similar problem with a 2016 F50. The fuel pressures were good and no error codes. The dealer couldn't duplicate the problem. In my case, hot fuel vapours were building up in the VST and pressurizing the VST to the point that the low pressure pump couldn't push the float controlled needle open to let in fuel. The VST wouldn't fill up and the motor in turn would starve for fuel and quit. By either releasing the pressure or cooling down, as soon as the pressure in the tank was released the needle valve would open, fuel would fill the VST and the motor would run.

There can be other issues that prevent fuel flow into the VST. A simple test for over pressure. On top of the VST you'll see a small rubber
cap that covers a schrader valve. Run the motor with the shroud off As soon as the motor stops press the schrader valve and release the pressure. There'll be some air. If it's lots, like letting the air out of a bike tire, then there's an over pressure issue.

In my case the pressure relief solenoid wasn't releasing sufficient pressure. It could be the volitility of your fuel causing too much vapour pressure. If the fuel cooler isn't getting enough water flow and your fuel is getting hot. A long fuel line in the sun heating up the fuel.

If it happens after a restart on a warm motor, letting the motor idle for a couple of minutes to cool down can help. From what I read, stored fuel can make more vapour.

I my case, I replaced the pressure reflief solenoid, flushed out the fuel cooler, shortened my fuel hose, use newer fuel and let the motor cool down for a few minutes.

So far, knock on wood, not more problems.

If it's not over pressure then I'm sure it'll be some other problem preventing fuel from entering the VST.

I don't have your service manual so I can't help you further. Yamaha's are great motors and there's tons of them out there, so I'm sure it's something fixable.

Good luck.
 
Thank you for the reply - I really appreciate your advice!
when your F50 was doing this did you need to let it cool down or release the pressure before the motor will start again?
My F40 quits but will start right back up instantly- but will only idle….
But I don’t need to do anything to it to get it going again.
Also - did you do the work yourself or end up bringing to someone?
Im no mechanic but I don’t mind tacking stuff if it’s within reason.

The other tip that someone mentioned the high speed fuel pump might be quitting after it heated up?
So it seems like the consensus is that this issue is fuel related at least.

Thank You again for the reply
 
I may have jumped the gun relating my problem. I was considering the cooling down and thinking vapour pressure but it might simply be an air leak. Letting it cool down just gives time for the fuel flow to recover.

I have a manual and was able to quickly narrow it down to the pressure relief solenoid. I was able to disconnect the VST air line bypassing the solenoid so no pressure would build up and the motor ran fine. The dealer has sold tons of these motors and never seen my issue.
I explained how I came up with the problem they agreed to put on a new solenoid.

When your motor stops, if you try priming your fuel line a dozen squeezes or so and then start your motor. See if your motor rev's up and runs. If it does, then I'd say your definately a fuel supply problem rather then a high pressure fuel pump.

I'd start with the easy stuff, line bent, kinked, plugged fuel filter, bad fuel hose etc.. Drain the VST and make sure there is fuel and no water. If you know someone with a yamaha borrow their tank and hose and try it.

If it runs on the other tank problem solved. If it continues to do it then your back to the VST.

Here's one. I forgot to open my tank air vent. The suction pulled down the top of the tank. The fuel pickup in the tank was a solid plastic straw that kinked and restricted fuel flow. Took me a bit to find that.

I'm afraid I can't offer more then that. I'm sure it's going to be something simple.

Good luck.
 
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