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CardenFam
04-14-2011, 12:48 AM
As much as I wish it were true my fuel gauge reads full all of the time. I have an 06 X2 with a MCX. I unplugged it and it drops to empty, so I think the sending unit is good its just out of adjustment. I noticed that there is 2 potientiometers on top of the sending unit, do these maybe adjust the sensitivity of the gauge or something. Any info would be appreciated.

Thanks in advance

mayo93prostar
04-14-2011, 07:51 AM
one of the pots is the empty adjustment and one is the full. If your gauge reads full, this may indicate a short in the sending unit. they pots should be labeled. adjust the full one first and see if you can get the gauge to come down some. if not, you probably need a new sending unit.

jdhart73
05-22-2011, 10:42 PM
Carden whats up man! Did you ever figure out your fuel sender issue? Mine reads more full than it is also.... looking for a fix!

CardenFam
05-23-2011, 12:10 AM
Haven't been back to the boat since we traded props. Father in law suffered a head injury cleaning up tornado damage so not much time for the boat. I think I am just going to buy a new sending unit from ebay since they are only $35, I just need to remove mine to measure the length.

nkknutson
05-23-2011, 12:12 AM
Mine also reads full all the time.....So I just fill up before every use

CardenFam
05-23-2011, 12:12 AM
Haven't been back to the boat since we traded props. Father in law suffered a head injury cleaning up tornado damage so not much time for the boat. I think I am just going to buy a new sending unit from ebay since they are only $35, I just need to remove mine to measure the length. Did you have any luck with the new prop? Windows look good!

davidstan
05-30-2011, 08:43 AM
my gauge also shows full all the time. my unit does not have the adjustment screws so i am wondering if anyone has a sender like mine that has a black cap that screws down on top of the tank? I have tried unplugging it and cleaning it then reinstalling and back to full it goes. I have the 45 gal 08 x2 mcx.

epnault
05-30-2011, 12:04 PM
Guys,
I worked with an engineer, from the sender manufacturer, last summer to calibrate my sender that doesn't have the screws like the older style. It involves jumping a couple of wires on the sender at power up on the boat. Unfortunatley the procedure I wrote down is on my work computer. It is pretty easy to do. I will share ASAP

Jason99T/A
05-30-2011, 12:28 PM
Guys,
I worked with an engineer, from the sender manufacturer, last summer to calibrate my sender that doesn't have the screws like the older style. It involves jumping a couple of wires on the sender at power up on the boat. Unfortunatley the procedure I wrote down is on my work computer. It is pretty easy to do. I will share ASAP

This would be very helpful. I purchased a new sending unit directly from Mastercraft that does not have any external adjustment screws for Full/Empty like the original unit I am replacing. I requested calibration info from the dealer and hope to hear back shortly.

davidstan
05-31-2011, 08:16 AM
Guys,
I worked with an engineer, from the sender manufacturer, last summer to calibrate my sender that doesn't have the screws like the older style. It involves jumping a couple of wires on the sender at power up on the boat. Unfortunatley the procedure I wrote down is on my work computer. It is pretty easy to do. I will share ASAP

I agree this would be helpful info to a lot of us. Geez there must be more than a few owners with this issue on this board. Thx for offering to post the fix.

agarabaghi
05-31-2011, 09:28 AM
Mine always reads empty. I think i have one of the newer units as it only see bolts that screw it into the gas tank.

I did try to short the - and + while the boat was on, and all that did was make the noise of reseting my dash (all the other gauges went back down then up to their proper place)....

Any suggestions?

bturner2
05-31-2011, 10:07 AM
07 X2, always full.

epnault
05-31-2011, 10:44 AM
Guys,
The issue I was having was that my gauge would only work from F to tank. Then when I restarted my boat it would read E at a tank. Although the description and procedure below is for an empty cal, I would assume you could do the same thing for a F cal (leave the sending in a full tank of fuel and short the sender to set the F cal). Below is a transcript from my email communications with Centroid engineering. Hope this helps guys.
Thanks
Eric



From Centroid:::::

What I usually have folks do is pull the clip off the back of the sender's connector, pop out the pins, and plug them in directly to the boat's harness connector. That way you can get at the pins for measuring voltages while the sender is connected. If you do this, I suggest the following:

--Make yourself a sketch of the wire colors on both sides of the connection so you dont forget what order to put the pins back in the sender's connector shell.
--It wouldnt hurt to put a little tape on the metal of the red wire's pin (the "handle" part, not the part that inserts into the harness connector). The red wire is battery voltage, and a little tape on the "handle" of the pin will keep you from shorting it to something while making your voltmeter measurements.

Setting the EMPTY CAL
It appears your Empty cal is set too high on the sender. Here's how to correct it:

--You'll need a jumper to short the White wire connection (Send) to the Black wire connection (Neg). An alligator clip is ideal. It needs to be something that you can remove after 2 seconds without doing much fumbling.

--You'll need an assistant to switch the power for you and watch the gauge for you.

--Have the sender out of the tank and connected, power OFF, and your jumper between Send and Neg (in addition to the normal connections, not instead of them).

--Have your power man turn ON the power and count "1000-1, 1000-2" (ie 2 seconds) at which time you should remove the white/black jumper.

--Your power man should have seen the reading be pegged above F for the 2 seconds you had the jumper applied. When you remove the jumper, the reading should first drop to below E then do some bouncing and finally finish at E.

--As a sanity check, you could insert the sender and see that the reading starts up scale as soon as the sender goes into the fuel instead of waiting until you get 3/4 of the way in.

davidstan
05-31-2011, 03:04 PM
This will help and thx. For a non engineer where is the boats harness (x2) and what does it look like and what kind of jumper? is that like a battery charger?

agarabaghi
05-31-2011, 03:06 PM
I will try the shorting method also, and see if my gauge wakes up.

epnault
05-31-2011, 06:58 PM
OK-the boat harness is the one that is on your fuel tank. There will be branch for the sender and your fuel pump on that harness.

To make a jumper you will need two simple alligator clips and a piece of wire.

davidstan
06-06-2011, 02:08 PM
Turns out I have a sender from Royce Ind and i spoke w/ them today about my inaccurate fuel gauge. When i described to them my insert, harness and wire colors they said someone put the wrong sending unit insert in my tank. My wires are black blue and red and the Royce engineer said they only put white wires for fuel tanks and blue wires for water tanks soooo my gauge is too short to measure accurate. Previous owner must of had a mechanic on crack or something.

zsqure
08-29-2013, 10:18 PM
Will have to try this tomorrow as my gauge has been reading full most of the summer and I know some hack has been into it. They couldn't even put in all the correct fasteners. 2 out of 5 are machine screws, the rest are sheet metal. So much for the threaded inserts in the tank.

Footin
03-02-2014, 08:40 PM
07 X2, always full.

Hey Burner, does your still always read full? Looks like mine does too. I thought I had a full tank but it looks like its about 1/2 full so I think I have a problem..

Snipe
03-03-2014, 11:16 AM
Guys,
The issue I was having was that my gauge would only work from F to tank. Then when I restarted my boat it would read E at a tank. Although the description and procedure below is for an empty cal, I would assume you could do the same thing for a F cal (leave the sending in a full tank of fuel and short the sender to set the F cal). Below is a transcript from my email communications with Centroid engineering. Hope this helps guys.
Thanks
Eric



From Centroid:::::

What I usually have folks do is pull the clip off the back of the sender's connector, pop out the pins, and plug them in directly to the boat's harness connector. That way you can get at the pins for measuring voltages while the sender is connected. If you do this, I suggest the following:

--Make yourself a sketch of the wire colors on both sides of the connection so you dont forget what order to put the pins back in the sender's connector shell.
--It wouldnt hurt to put a little tape on the metal of the red wire's pin (the "handle" part, not the part that inserts into the harness connector). The red wire is battery voltage, and a little tape on the "handle" of the pin will keep you from shorting it to something while making your voltmeter measurements.

Setting the EMPTY CAL
It appears your Empty cal is set too high on the sender. Here's how to correct it:

--You'll need a jumper to short the White wire connection (Send) to the Black wire connection (Neg). An alligator clip is ideal. It needs to be something that you can remove after 2 seconds without doing much fumbling.

--You'll need an assistant to switch the power for you and watch the gauge for you.

--Have the sender out of the tank and connected, power OFF, and your jumper between Send and Neg (in addition to the normal connections, not instead of them).

--Have your power man turn ON the power and count "1000-1, 1000-2" (ie 2 seconds) at which time you should remove the white/black jumper.

--Your power man should have seen the reading be pegged above F for the 2 seconds you had the jumper applied. When you remove the jumper, the reading should first drop to below E then do some bouncing and finally finish at E.

--As a sanity check, you could insert the sender and see that the reading starts up scale as soon as the sender goes into the fuel instead of waiting until you get 3/4 of the way in.

You must then stay with the type of gas you calibrated your unit with. Ethanol and 0 Ethanol read completely different. I too had that problem. When you short the two wires you also need to jump them across a 33 ohm resistor. Joel at Introit is very helpful, but only responds to e-mails. Good luck.

Snipe
03-03-2014, 11:18 AM
Guys,
The issue I was having was that my gauge would only work from F to tank. Then when I restarted my boat it would read E at a tank. Although the description and procedure below is for an empty cal, I would assume you could do the same thing for a F cal (leave the sending in a full tank of fuel and short the sender to set the F cal). Below is a transcript from my email communications with Centroid engineering. Hope this helps guys.
Thanks
Eric



From Centroid:::::

What I usually have folks do is pull the clip off the back of the sender's connector, pop out the pins, and plug them in directly to the boat's harness connector. That way you can get at the pins for measuring voltages while the sender is connected. If you do this, I suggest the following:

--Make yourself a sketch of the wire colors on both sides of the connection so you dont forget what order to put the pins back in the sender's connector shell.
--It wouldnt hurt to put a little tape on the metal of the red wire's pin (the "handle" part, not the part that inserts into the harness connector). The red wire is battery voltage, and a little tape on the "handle" of the pin will keep you from shorting it to something while making your voltmeter measurements.

Setting the EMPTY CAL
It appears your Empty cal is set too high on the sender. Here's how to correct it:

--You'll need a jumper to short the White wire connection (Send) to the Black wire connection (Neg). An alligator clip is ideal. It needs to be something that you can remove after 2 seconds without doing much fumbling.

--You'll need an assistant to switch the power for you and watch the gauge for you.

--Have the sender out of the tank and connected, power OFF, and your jumper between Send and Neg (in addition to the normal connections, not instead of them).

--Have your power man turn ON the power and count "1000-1, 1000-2" (ie 2 seconds) at which time you should remove the white/black jumper.

--Your power man should have seen the reading be pegged above F for the 2 seconds you had the jumper applied. When you remove the jumper, the reading should first drop to below E then do some bouncing and finally finish at E.

--As a sanity check, you could insert the sender and see that the reading starts up scale as soon as the sender goes into the fuel instead of waiting until you get 3/4 of the way in.

You must then stay with the type of gas you calibrated your unit with. Ethanol and 0 Ethanol read completely different. I too had that problem. When you short the two wires you also need to jump them across a 33 ohm resistor. Joel at Centroit is very helpful, but only responds to e-mails. Good luck.