incorrect fuel reading

[blacksapphirez]

So the dealer has supposedly replaced the fuel sending unit but it is still reading incorrectly. is there a quick fix for this or do I have to go back to the dealership? it is 2 hrs away and to make the matters worse, they lost a screw for the fuel sending unit...

FACTS
Gas was filled up, gallons used was reset and have consumed 24 and some odd gallons when the pictures were taken.

 

[Murf'n'surf]

Looks like you are throttling up and putting the boat at an angle, thus the fuel reading will be inaccurate.

 

[blacksapphirez]

20+gal of discrepancy? I wouldn't think so... and this was within 5minutes...if not less

 

[Murf'n'surf]

Yep. Very possible. My 230 will read 1/2 tank at idle and nearly empty while running in the hole.

 

[blacksapphirez]

ok before my outing, the gas was filled up(multiple cut offs) and the gauge was still showing less than full, about 3/4 but through out 24 gallons of usage, it went completely empty at some point and danced around empty and a 1/4.

I dont remember having such a huge variance.

 

[swatski]

That is a big error, but I'm not surprised, those are always non-linear and out of wack. If your "gallons used" works well, you should be in good shape, that is what I have been using.

 

[Smassey22180]

Can you pull the sending unit and make sure the float is not sinking? If it is, perhaps the dealer can just send you a new one. My 09 has the SSL 12 and the float is not floating.

 

[Mainah]

Not sure about Yamahas but can say that seadoo boats had quite an issue with the float or the contacts on it deteoriating. Someone made an aftermarket one that worked much better than the stock on and gave more consistent read outs.

In my 16 242 ls I can go from showing 85% in a level boat to 100% with the bow in the air for an extended period like when towing.

 

[Julian]

Not showing full when you just filled it is a problem. @Murf'n'surf is correct that the readings will vary when moving (throttling up in particular)...but it sounds like you have a bigger problem. The dealer is the only one who's going to fix it under warranty....

 

[blacksapphirez]

I sent them an email about their incomplete work and asked to send me the fuel sending unit so i can fix it my self.

last time it was there(for this fix) spent 3 weeks there....and it is 4 hour round trip!!!!!!

 

[Julian]

Yeah...I hear ya...driving back and forth to the dealer is a pain....mine is 2 hours away round trip....so half the pain of yours and still means I have to take time off work to do it or only go on Saturdays (boating days).

You'd think these gauges would build in a floating average over a 2-4 minute period to flatten out the spikes from acceleration..... @Mainah here is your next invention!

 

[0627Devildog]

You'd think these gauges would build in a floating average over a 2-4 minute period to flatten out the spikes from acceleration..... @Mainah here is your next invention!

That is a terrific idea. . . . I have a similar issue. There have been several times where on plane it shows MORE fuel then we have, just to come off plane and get hit with the low fuel alarm. Literally happened the first time we took her out, and we were in unfamiliar waters too. Luckily we have yet to be left stranded by this. But it must have happened at least 3 times in 3 seasons.

 

[MNdrifter]

I don't trust the gauge. If it shows 1/2 tank or less when we return to the marina, I fill it up just to be sure.

 

[blacksapphirez]

the "gallons used" is pretty spot on so I can go up to about 40gal(which i never have) before filling up.

freaked me out at first when this happened...at the beach...in an unfamiliar area... made me get fuel from marina which was like $4 a gallon! jeeeez only took about 10gal but still.

 

[Smassey22180]

Yep. Very possible. My 230 will read 1/2 tank at idle and nearly empty while running in the hole.

Where is the sending unit on the 2005? For my 2009 the sending unit is in the back 1/3 of the tank. If it were much farther forward, what you say above may happen.

 

[haknslash]

Hmm I will have to pay attention to my fuel gauge next time I'm out but I don't recall mine varying that much, although most times I'm checking the fuel level it's while I'm underway.

 

[Mainah]

@Julian - I can think of one complex way to get a fuel level reading that would be accurate all the time. Simple smoothing would not be very accurate. So that said is it worth $100 bucks as a product to someone? How about lots of people? As @blacksapphirez pointed out the gallons used is quite accurate.

 

[Julian]

My fuel tank gauge seems to be pretty accurate on the connext screen....

 

[0627Devildog]

@Julian - I can think of one complex way to get a fuel level reading that would be accurate all the time. Simple smoothing would not be very accurate. So that said is it worth $100 bucks as a product to someone? How about lots of people? As @blacksapphirez pointed out the gallons used is quite accurate.

It "should" be worth it to Yamaha. . . . .

 

[Mainah]

Weather it is cars or boats it would seem that they are all dependent on where the pickup is in the tank and the vehicles x/y axis and g load all relative to level and 0g (attitude). Has been that way for a very long time. The good part about this is that in most cases the fuel pump pickup is located very close to the fuel level sender pickup so even in cases of extreme off axis or g load operation it can indicate when the fuel system is close to no longer being able to pump fuel from the tank into the lines. The reason this does not stop the engine from running even when reading zero in extreme attitude operation is that there is still fuel in the line and filters and the extreme attitude operation condition usually does not persist for very long. If it does persist for an extended period and the engine quits from being fuel starved simply return the vehicle/boat to a normal operating attitude and the engine should be able to start without issue.

I imagine that the rock crawler community has come up with a solution for extreme off axis operation a long time ago given that it could be all over the up down or sideways orientation map. I would guess that Nascar had figured out the best place for the fuel pick up given the the g forces and vehicle attitude they experience turning left on a banking for about half of each race. Likewise I would venture a guess that Yamaha has determined the best possible place to put the fuel pickup given the average attitude of our boats while in operation. I bet there is some complicated engineering going into how fuel levels are monitored on planes and how they pick up fuel for the engines.

Add this to the list of things we don't normally think of but there is likely engineering behind. In all I would not be too worried about a fuel reading that is only off under extreme attitude conditions in our boats. However if it always read wrong then I would replace the needed parts to return it to factory spec.

Now where is the nerd rating/trophy because I must have earned it by now