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Humm from both engines with key on (engines off) in E-Series boat

Julian said:
Yamaha says the fuel pumps are under the floor.....but I'll be asking again when I go back to the dealer. As long as everyone has the same buzz......I feel a little better.... :)
Click to expand...

I agree with that statement. When I raise the engine hatch it gets much louder because of the insulation but I am pretty sure the source is forward of that area on the other side of the bulkhead near the fuel tank. I took the carpet off and saw the bolts but did not remove them since I feel pretty confident about what it is. I will finally get to it when I check the tank as the manual suggests but I will have to do that on a weekend when I can not go to the lake.
 
Get the dealership.... or someone.. to install a inline fuel pressure gauge... turn the switch on.. if the gauge jumps u there u have it.... I mean if I have a bran new high dollar top of the line yamaha x series boat.. I would immediately start taking stuff apart to to say.... up... that's what that sound is!! :)
 
I can confirm no noise from my engines with keys on on engines off. Tried with throttles in multiple positions. Mine is a 2016 242 ls so the e/x series do have some different parts like the gate servos. Is this an e/x series issue only?Given the members saying they here it My guess is that it could be and could narrow down the culprit.
The fuel pumps are in the tank and the fuel lines do come through the bulk head to the fuel rails so I guess those are also a possibility.

@Julian and @Adrenalinejunky Good luck tracking this down.
 
242LSE definitely hums with the key on, doubt it's the fuel pump, sounds like something to do with the ignition/ECU being on - just learning also!
 
Yep I noticed the buzing sound the first time out when in float mode. On another thread someone told me about holding the nav light button for a few seconds while the key is off to boot up Conex...
 
I have no skin in this except curiosity at this point. Must say my money is on something to do with the gate servos. The servos need to maintain position which means there is a control signal and power supply for them to do that and could be active with keys on and engines off. I don't know where the servos are located but they could be the noise source as well. Wonder if the sound changes with the binnacles in different positions or as they are moved?
 
Mainah said:
I have no skin in this except curiosity at this point. Must say my money is on something to do with the gate servos. The servos need to maintain position which means there is a control signal and power supply for them to do that and could be active with keys on and engines off. I don't know where the servos are located but they could be the noise source as well. Wonder if the sound changes with the binnacles in different positions or as they are moved?
Click to expand...
The servos are under the helm...under this black box:
img_3606-jpg.27830
 
So where is the power supply for those and where is the controller for them? Given that there is logic involved that prevents sub moves as well as other things (possibly to prevent strain on the servos) it is more than just the binicles providing the input to the servos. Find the brains and/or power supply and you may find the noise source ( in my over the internet with only second hand human information to go off of opinion) ;)

My thinking is that the noise seems to only be on the e series and the main difference is the gate system. The throttle system is different as well but given that that the non-eseries already use a cable to pull an output module that sends an electronic signal I think the gate system is the more likley culprit.

Good Luck.
 
I'm thinking it has all to do with the push button starts and key system in the E-Series boats. In the non E-Series, you only turn on the engines with the keys to start the engines. At other times all the electronics are operational. I think the linkage they've put in to the one key for both engines and push button starts somehow triggers the fuel pumps to activate in advance so both engines have fuel pressure so that they start right away from the push buttons.
 
Last edited:
Forgot about the push button start. That certainly makes sense as well.
 
And since the point of the push button start is that you can just push a button and off you go....if you have to turn off the key to eliminate the buzzing sounds, then you've actually made starting up an even longer process due to the Connext screen start up time (not to mention the killer BEEEEEEEEEP when it starts up!). So I guess I just need to get the stereo working so I can drown out the buzz! LOL
 
It is the throttle bodies. Unplugged them and sound stopped. Caution, you will get check engine indicators and have to turn off batteries to clear. But I have now been very close and personal with this area and even have a mark on my face to prove it.
 
So @Adrenalinejunky, are you saying it is in the throttle body and it is not the fuel pumps?
 
buckbuck said:
So @Adrenalinejunky, are you saying it is in the throttle body and it is not the fuel pumps?
Click to expand...

That is correct. I pulled the cover over the fuel tank and the noise was not there so I got intimate with the intakes on the other side and even though I was skeptical it seemed like the noise was coming from the throttle bodies. I followed the harness to the plugs in the pictures above and disconnected them one at a time and each one stopped making the noise. At that point all was quiet. I turned the key off before I plugged them back in. Once I turned the key on the throttle bodies started the noise again.
 
Last edited:
HELLO YAMAHA! Are you listening?
Oh, that's right. They are there in the background, somewhere.
 
Looks like it is an electronically controlled throttle plate. Hmmm...where's our VW guy. He knows about this stuff.
 

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  • throttle body.png
    throttle body.png
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Went to YamahaSportsPlaza and they show both the E series and non-E series having the same throttle assembly at $660.
 
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