Fuel gauge/sender problems

[qdiver]

Hey Guys,
I have a 93' Seafarer with the single 93 gallon tank that my fuel gauge is showing on the positive side. When I fuel her up all the way my gauge only shows a bit past 3/4 not full it's not a bad problem to have but I head out quite far offshore and not real comfortable with the gauge being off like that even if it's on the good side. Sometimes we want to explore other fishing spots when the bite is bad but I worry about if I really only have 1/2 a tank or not to get back in safe and still wonder around some. Looking for opinions? is there an adjustment like in Ohms resistance on senders ? the gauge seems to be ok and I can always replace it easily enough just hate to do it and still have the problem.
Input would be appreciated.

 

[DennisG01]

The one thing I'm not sure about yet with these Yamaha gauges is whether or not there is a setting - or a reset - for fuel. But, aside from that...

First, remove the pink wire at the sender and your fuel gauge should drop to zero. Second, touch the pink wire to ground (at the sender) and the gauge should spike to full. If that checks out, everything is good from the sender wires to the gauge.

There's no adjustment on the sender. They just get worn out over time. But, you can try removing it and cleaning it off - both the windings and the arm. Then, move the arm by hand and see if the problem still persists. You might try bending/re-shaping the arm to make better contact with the windings or in a slightly different spot. If no joy, replace sender.

 

[seasick]

It doesn't matter what the display reads. What matters is that you know what a reading means in terms of available fuel and that you know what your typical burn rate is. The display isn't super accurate and will change depending on trim, load, etc.
Over time you should be able to judge how much fuel you will need for a given trip and what you expect the display to read.
For example, if your digital displays show 4 bars ( I assume that is about half a tank) and you add 40 gallons, whatever the display reads, it should get back to 4 bars after burning off 40 gallons. If you burn 15 gallons an hour at typical cruise speed, after 2 1/2 hours of cruising you should be back to 4 bars.
My point is not to relay on the gauge, use your experience with the burn rate, sea conditions, cruise speed, and load to estimate what you will burn on a trip.
Have fun!

 

[qdiver]

Hey Dennis,
I went to the boat today and ran the checks you recommended. Sure enough the fuel gauge went to 0 when disconnected and full when grounding the (red wire in my case) sending wire.
I should have mentioned that I do not have the Yamaha fuel gauge/MPH pod I just have the Yamaha RPM gauge that has the trim & oil, temp light on it. I have a regular analog fuel gauge and it did deflect to both extremes when running the wire disconnect & ground test. So the gauge is good, I will look at the sender when I can put the boat up as it's fishing season now. But great advice and definitely ruled out the gauge being the problem.

Seasick, you are 100% correct and I have been doing just that, filling up and then topping off on the next trip to know how many gallons I am burning by the miles I travel that my Garmin records at the trip meeter function.

You know I feel somewhat foolish as I bought a brand new Yamaha fuel management kit (gauge/sensor & wiring harness) about 4 months ago online and have it sitting here in my office doing nothing for me. I guess I better get to installing it I just did not want to have the boat down in the peak off summer in case I run into a snag with the install and was going to wait until grouper season closes.

I have to take off the rear center cover where the auxiliary fuel tank would be bellow as it's gotten soft and I have to re-core it, at that time I will also remove the front one on top of the main tank and replace the sender in the tank with a Wema as I read on here they are good units and install the Yamaha fuel flow metering sensor at that time as it has to be tied into the hose exiting the tank going to the motor. Is that usually were it's installed?
Thanks for the feedback guy's !!

I'm open to any additional comments..
Miguel

 

[seasick]

Hey Dennis,
I went to the boat today and ran the checks you recommended. Sure enough the fuel gauge went to 0 when disconnected and full when grounding the (red wire in my case) sending wire.
I should have mentioned that I do not have the Yamaha fuel gauge/MPH pod I just have the Yamaha RPM gauge that has the trim & oil, temp light on it. I have a regular analog fuel gauge and it did deflect to both extremes when running the wire disconnect & ground test. So the gauge is good, I will look at the sender when I can put the boat up as it's fishing season now. But great advice and definitely ruled out the gauge being the problem.

Seasick, you are 100% correct and I have been doing just that, filling up and then topping off on the next trip to know how many gallons I am burning by the miles I travel that my Garmin records at the trip meeter function.

You know I feel somewhat foolish as I bought a brand new Yamaha fuel management kit (gauge/sensor & wiring harness) about 4 months ago online and have it sitting here in my office doing nothing for me. I guess I better get to installing it I just did not want to have the boat down in the peak off summer in case I run into a snag with the install and was going to wait until grouper season closes.

I have to take off the rear center cover where the auxiliary fuel tank would be bellow as it's gotten soft and I have to re-core it, at that time I will also remove the front one on top of the main tank and replace the sender in the tank with a Wema as I read on here they are good units and install the Yamaha fuel flow metering sensor at that time as it has to be tied into the hose exiting the tank going to the motor. Is that usually were it's installed?
Thanks for the feedback guy's !!

I'm open to any additional comments..
Miguel

Yes, I like the Wema models but that all suffer the same issues with accurate readings when the angle of the tank changes.
A few tips; If the tank is full or close to full, there is a good chance that fuel will pour out when you unscrew the sender plate so make sure the tank is not full ( 1/4 or so is best). The best way to get the correct Wema unit is to remove the sender plate and measure the dept of the tank. Call Wema with that measurement and they will give you the part number for the correct sender. It should end about an inch above the bottom of the tank. Don't over tighten the flange screws, you can distort the mounting flange and cause leaks. Do you need sealant? Some say yes, some say no. For me if the flange is flat, not pitted and clean, I will just use the gasket. If you want to use sealant, use one meant for gasoline applications.
Read and follow the instructions for the fuel flow sensor especially with respect to mounting position and orientation. Some of the sensors I have dealt with ( I don't have direct experience with a Yami fuel flow sensor install) are pretty particular about plumbing config and height.

Have fun!

 

[DennisG01]

Cool, at least you've got the issue narrowed down to the culprit. I don't really have anything to add to what Seasick wrote (you know, they make a pill for that!). I've used Moeller stuff quite often (I work part time at a marina), but I've heard plenty of good things about Wema, too. I just don't have any personal experience with Wema. Good luck with the rest of the fishing season!

 

[seasick]

Cool, at least you've got the issue narrowed down to the culprit. I don't really have anything to add to what Seasick wrote (you know, they make a pill for that!). I've used Moeller stuff quite often (I work part time at a marina), but I've heard plenty of good things about Wema, too. I just don't have any personal experience with Wema. Good luck with the rest of the fishing season!

That comment about the pill is quite funny and the first time something like that has been mentioned.
Thanks for a good chuckle!
And yes, I can get seasick on my boat. I can get seasick on an escalator

 

[DennisG01]

That comment about the pill is quite funny and the first time something like that has been mentioned.
Thanks for a good chuckle!
And yes, I can get seasick on my boat. I can get seasick on an escalator

You know, I've meant to say it before but since I'm relatively new to the forum I always thought "Nah, someone else has certainly said it before me"!

 

[qdiver]

Hey, that was good guy's and thanks for the feedback...
Heading out Saturday morning as it's a full moon and red grouper is over Sept. 29 here in Fla. don't you hate all these federal/state restrictions .... yeezz
But I guess we have to leave fish for our kids.. :bang

 

[ROBERTH]

Just another vote for the WEMA. Out of all the years of replacing fuel sending units, these are the best designed in my opinion and are the most stable. If boat is rocking around, they don't fluctuate. There is no adjustment needed if you order the correct length.
My main gauge went after first year of getting this boat, so it was 20 years old and looked to be original. The very next year, the aux. tank failed, so they seemed to be at their end of life. However, I am using ethanol fuel so maybe the age of them was not able to handle the ethanol and that is what made them go out. dunno....but so far, these WEMA's are doing very well and are very accurate. Plug and play!

 

[qdiver]

Great info Roberth,
With your confirmation the WEMA will be the route I go. Put it this way, I have not heard any negatives on them and I like that clean plug/connector they have, should help keep some of the corrosion away.
By the way I see you have an awesome set up / 92' Sailfish w newer Yam's how do you like it? that's got the SeaV2 hull right?
What's your fuel burn, do you know? That's my next Grady God willing...
Thanks,
Miguel

 

[ROBERTH]

I don't think you can go wrong with the WEMA design!

Yes, it is the SeaV2 design. This boat is great in all aspects. Easy to handle, easy to get to any part of the boat and is a very good ride even in rough seas!
Fishing is excellent and we constantly run out 50-60 miles and back.

The motors are excellent. Lots of power for this size boat. It is on plane almost instantly and top end is 49mph with current props.
Fuel burn at cruise with light load, I have seen 1.8mpg at 32mph. Full load, 200# ice, Bait/tackle and 5 guys with lots of gear and 2-3' seas we will see approx. 1.5 to 1.6mpg at 32mph.

On days when I have to put the tabs down and bury the nose due to heavy seas, we can see down to 1.2 to 1.4 mpg and going slower, around 22-25mph on those days.

 

[qdiver]

That's a great combo,
I am enjoying my Seafarer as it's my first Grady (my 5th boat) and it was my goal to get into a Grady as their reputation is bar none and yes they are tanks. My 22' has taken on some tough seas in the Gulf coming back in as the weather changes from one hour to another sometimes.
We go out 40/60 miles off west Fl. and it can get hairy sometimes. I have a bud that has a 37' Intrepid with twin 300's and he goes out 100+ miles to the middle grounds and comes back loaded with fish almost every time.. It all depends, sometimes at 30 miles witch is only 80' deep here you hit it hard and I come back with a full cooler but I would like the added security of a heavier boat, wider beam & twins just in case..... to go out that far.

I have been looking and really like the bracket options in the older Grady's as yours has, as you still have a huge fishing area out back and that closed transom (as mine is) is terrific for big swells coming form the rear as they do sometimes when anchored. Don't get me wrong, a 270 or 282 Sailfish would be great also but there are trade offs for real fishing when you loose deck space and the fuel cost go up $$$

Those are great fuel numbers for 2 stroke twins on you 25' Sailfish, my OX66 seems to do real well on fuel also but I need more range as I don't have the second fuel tank.
Hey, work in progress .. second tank add in.. ???? or sell and upsize :hmm

 

[Firenailer]

Good discussion and helpful info guys. I just had the sender replaced on my 3 month old boat and for some reason it now reads 3/4 with a full tank. Not good. I'm going to talk to the dealer about replacing it again and will also ask about this WEMA product.

A direct connect would make me feel better than the cheapo crimps they used on the last one too!

 

[ROBERTH]

Firenailer, i had similar issue as you after replacing my last gauge a d found it to be a bad terminal end. I cut it off and installed a new one and no problem since.

 

[Firenailer]

Thanks! I'll give the connection another look and see if it reads properly.

 

[Doberman]

For what its worth, I have chased a similar 3/4 reads as full issue with my 1998 Islander and finally concluded it was due the angle of the main tank when the boat sits in the water. To net it out placing a level on top of main tank show it was not parrallel to surface of water, sat high at the bow by several degrees. Given the design of tank both the Fuel fill and vent hose unfortunately sit at the aft end thereby creating a situation where you can never fill the tank beyond the 3/4 level (ie you will have overflow before you can use the air bubble that sits by the bow end of tank. For my own piece of mind, I ended up installing an aux tank versus thinking of ways to relevel the tank. BTW I did replace the full WEMA sender ( it also would max out at 3/4. When I did run tank to empty, could never refill more than say 85 gallons versus the stated 135 gallon tank capacity. I have gotten similar confirmation from other knowledgeable grady owners of similar vintage. Anyway FYI