Gas Gauge showing 7 of 8 bars (1993)

[Rocketboy]

I have a 1993 Yamaha with the Yamaha gauges. I got this boat this winter and it showed 7 of 8 bars. It was full and I have put on about 30 miles of pretty hard running. Still shows 7 of 8 bars.

On the tank there is a black wire and a red wire. I did some looking on line lastnight and I kept reading about other colors. I also was going to take them off and clean them but when I try to loosen them the wire is turning with the nut and I didn't want to break it......

Any advice?

Thanks

[DennisG01]

It would be helpful to know the tank size. Sometimes, you sort of have a "buffer" at the top. Meaning, it stays at full for a little longer, before starting to move down. Also, the angle of the boat can affect what the gauge reads from one time to another.

It should be a pink wire. If it's red, someone did some rewiring. Just hold the ring terminal from moving while you loosen the nut.

[Rocketboy]

It would be helpful to know the tank size. Sometimes, you sort of have a "buffer" at the top. Meaning, it stays at full for a little longer, before starting to move down. Also, the angle of the boat can affect what the gauge reads from one time to another.

It should be a pink wire. If it's red, someone did some rewiring. Just hold the ring terminal from moving while you loosen the nut.

Thank you- I will try that next weekend when I get back to the boat. Interesting to hear that it has been rewired!

[boscoe99]

Here is the solution to your sender problem.

http://www.centroidproducts.com/yama-cal.pdf

[DennisG01]

It could be that you are just mistaken on the color. But if it is, indeed, rewired then I would first check that the wire in question does go to the gauge. Color of the wire is one way to check, but I would take it a step further and Ohm (continuity) the wire from end to end.

[dngharvey]

Have the same set up on an 18'. Shows full for quite a while before starting to drop, found it to be pretty darn accurate. Also keep careful records, always have. Write it down, great back up.

[99yam40]

easy way would be to keep some extra cans of fuel with you and run it until it is empty .

then add what you have to get back home( noting the level gauge and how much you put in changes).

then as you add fuel stop and record how much and what the gauge shows from time to time

[scofflaw]

easy way would be to keep some extra cans of fuel with you and run it until it is empty .

then add what you have to get back home( noting the level gauge and how much you put in changes).

then as you add fuel stop and record how much and what the gauge shows from time to time

Then when it goes empty, it hits the lean sneese and everything goes kapooey ?

[99yam40]

1st sign of problems with motor running out of fuel you just turn it off or it shuts down on its own..
no lean sneeze while running at high RPM that I ever heard of.
lean sneeze it at idel as far as I have seen

if run for long periods of time lean it will get a piston or 2 maybe.
like so many try to see if it will get better , if I do this or add that to the fuel

[zenoahphobic]

I also have that 8 bar fuel indicator. I am also uneasy with what it shows, mainly that it can change a bar or two from trailer to water or even between sitting and planning (not a great deal of change in boat attitude though), so difficult to know exactly what fuel one really has.
I have about 185 litres and each bar would be a bit less than 25 litres and it seems, atleast in the middle range that it is linear. Never having run out of fuel I still worry about it's accuracy at the bottom. Although I suspected the sender sticking, I did drive some considerable time, in terrible seas at night across a bay, with it blinking empty. My fingers still have not completely straightened from their crossed positions on that night.
One day I will try to adjust the angle of tilt of the trailer to what it might be at smashing through waves, and pump out and measure the fuel noting the bar change, or indeed how long it actually reads empty.
Its pointless always to carry excessive fuel to relieve anxiety; and also a bit leaving it to chance by roughly calculating what fuel you may need for the outing, by adding that to the existing 1/4 or 1/2 tankfull . I am too stingy to fill up at $300 and leave that fuel to go stale .
So I need more detail to what that gauge shows (albeit properly adjusted), so I am getting a fuel flow meter and MNEA 2k setup (I only have useless 0183 Lowrance at moment) and hopefully relieve a lot of anxiety.

[boscoe99]

I also have that 8 bar fuel indicator. I am also uneasy with what it shows, mainly that it can change a bar or two from trailer to water or even between sitting and planning (not a great deal of change in boat attitude though), so difficult to know exactly what fuel one really has.
I have about 185 litres and each bar would be a bit less than 25 litres and it seems, atleast in the middle range that it is linear. Never having run out of fuel I still worry about it's accuracy at the bottom. Although I suspected the sender sticking, I did drive some considerable time, in terrible seas at night across a bay, with it blinking empty. My fingers still have not completely straightened from their crossed positions on that night.
One day I will try to adjust the angle of tilt of the trailer to what it might be at smashing through waves, and pump out and measure the fuel noting the bar change, or indeed how long it actually reads empty.
Its pointless always to carry excessive fuel to relieve anxiety; and also a bit leaving it to chance by roughly calculating what fuel you may need for the outing, by adding that to the existing 1/4 or 1/2 tankfull . I am too stingy to fill up at $300 and leave that fuel to go stale .
So I need more detail to what that gauge shows (albeit properly adjusted), so I am getting a fuel flow meter and MNEA 2k setup (I only have useless 0183 Lowrance at moment) and hopefully relieve a lot of anxiety.

I had the same issue with my fuel quantity system. Sender was at the back of the tank. The boat on plane had about a 6 degree nose up attitude which sent more fuel to the back of the tank, causing the gauge to read a bit higher than normal. About 12 gallons worth in my case with a 100 gallon tank.

I just knew that when on plane I had less fuel than indicated. Not an issue once I got used to it.

[zenoahphobic]

Rather my situation than yours. Atleast I have more than indicated, whereas knowing you have less I'd be worried coming off the plane then sucking air, but in a way less worried because you are under a placebo affect (less inclined to argue with an instrument because after all you would not have guage that is inaccurate - would you?)
My sender is mid tank as it should be to average out the fuel shift between bow up and bow down. Would it be better to have more senders and average out to get a more, all occasions, accurate measure? Better to go fuel flow calculation system (although much more costly)?

[boscoe99]

Rather my situation than yours. Atleast I have more than indicated, whereas knowing you have less I'd be worried coming off the plane then sucking air, but in a way less worried because you are under a placebo affect (less inclined to argue with an instrument because after all you would not have guage that is inaccurate - would you?)
My sender is mid tank as it should be to average out the fuel shift between bow up and bow down. Would it be better to have more senders and average out to get a more, all occasions, accurate measure? Better to go fuel flow calculation system (although much more costly)?

Yes. Absolutely.

Some air planes have many many probes in their wings from the root to near the tip. A computer looks at all of the probes and thru some algorithms and such derives the amount of fuel in each tank.

Fuel flow calculation system are fraught with problems of their own. If someone comes along in the middle of the night and takes a five finger discount with your fuel supply the calculation system won't know about it. You start out thinking you have much more fuel than you really have.

Being a belt and suspenders type I like having both types.

[zenoahphobic]

I am considering that I personally perhaps need suspenders. Something to do with waist getting bigger than the hips. They tell me if you can nolonger see your pecker when you pee, good time to invest in them because you'll eventually need them.