61 Fuel Sending unit

[ramos291]

I could use some help getting the sending unit to measure correctly. Does anyone know what the Ohms reading are? I just cant get the sending unit to show the correct level of fuel.
Thanks.

[YellowRose]

61 Fuel Sending unit

If your sending unit in the tank happens to have a brass or plastic ball on the end of it, it might have a hole in it. Mine did, and the plastic float filled up with gas and was giving me false readings. I ended up putting a whole new sending unit in with a new float because mine was probably, from the looks of it, the original one.

[simplyconnected]

...Does anyone know what the Ohms reading are?...

10-ohms when full and 100-ohms when empty.

BTW, your temp sending unit and gauge read the same. - Dave

[ramos291]

Great information. Another question, what direction should the inlet tube face and float inside the tank face? Left,right, front, back, deep or shallow.
Thanks for sharing all of your knowledge with these birds.

[jopizz]

There's a locating tab on the sender. It should only be able to go in one way.

John

[ramos291]

Thank you John for that note on the tab. I haven't noticed a tab but I will look closer. The current sending unit and the one before could be set in in any orientation it appeared. Again, I will look closer.

Thanks.

[ramos291]

ok so I found the location tabs and how it fits into the cut outs for the tabs in the tank. The sending unit I was using was small enough that the tabs did not come close to the cut out, there for its position could be where ever I put it in. I have gotten a new one and the tabs do reach the cut outs. However, with a full tank of gas it only indicates 3/4 of a tank. It seems as though the float doesn't have enough room to travel up and indicate full. The only way I have been able to get the sending unit to measure/indicate full is to rotate the sending unit to allow it to float higher and show a full tank. Very confusing deal.
Thanks for all your help. I have learned a few things.

[YellowRose]

61 Fuel Sending unit

Randy, it could very well be that your gas gauge is not indicating correctly. If you have a full tank that needle should be pointing to the Full indicator on the gauge. On Squarebirds there is an adjustment on the back of the gauge with pin wheels that you can make. I do not know if Bulletbirds are the same, but someone like jopizz can probably tell you that. You will have to take the gauge out to get to them though. The information on this is in the Technical Resource Library, the link to which is always part of my signature element and that of John ~ jopizz also.

[simplyconnected]

...It seems as though the float doesn't have enough room to travel up and indicate full. The only way I have been able to get the sending unit to measure/indicate full is to rotate the sending unit to allow it to float higher and show a full tank...

I'm reading your words carefully. You ARE able to get the gauge to read, 'F', so do not adjust your gauge.

Most sending units come with instructions that explain, there are adjustments that may be necessary, usually by bending the float arm. The range of motion should be strictly up and down, not sideways.

Think of it this way, if the arm is too long the float may drop to the bottom but it may also go to the top of your tank without reaching the resistor's top stop. If you shorten the travel by bending the float arm closer to the pivot, the resistor's range will widen.

Of course, if the float arm is too short the gauge will indicate 'F' before it really is full AND it will show 'E' before the tank is really empty. This arm adjustment is not precise or hard to do. Use common sense and trial and error. If you can make your gauge indicate properly with the sending unit out of the tank, it should likewise indicate properly when installed in the tank. - Dave

[jopizz]

There are stop tabs on the sender both in the up and down position. If your sender arm is not going down far enough bend the tab slightly so the arm drops farther down. I've taken out original senders where those tabs are bent quite a bit so they need to be adjusted to get an accurate reading.

John

[ramos291]

I'm reading your words carefully. You ARE able to get the gauge to read, 'F', so do not adjust your gauge.

Most sending units come with instructions that explain, there are adjustments that may be necessary, usually by bending the float arm. The range of motion should be strictly up and down, not sideways.

Think of it this way, if the arm is too long the float may drop to the bottom but it may also go to the top of your tank without reaching the resistor's top stop. If you shorten the travel by bending the float arm closer to the pivot, the resistor's range will widen.

Of course, if the float arm is too short the gauge will indicate 'F' before it really is full AND it will show 'E' before the tank is really empty. This arm adjustment is not precise or hard to do. Use common sense and trial and error. If you can make your gauge indicate properly with the sending unit out of the tank, it should likewise indicate properly when installed in the tank. - Dave

Thank you Dave for your help here. If Im understanding you correctly, I need to drop the sending unit in matching its tabs with the tanks cut outs and make adjustments as needed by bending the float arm one way or the other to get it to read correctly? I will give that a try. I have done this before with other sender units but I wasn't aware of the location tabs.
I am able to get the sender to measure Full/Empty when the unit is out of the tank, just not while in the tank. No instruction were included. I think its just a matter of patients and time.
Thank you Again

[simplyconnected]

Randy, I'd like to demonstrate different results you can get by using different length float arms and/or bending the ones you have.

These cannot change:
The depth of your fuel tank,
How high the sending unit sits in relation to the mounting,
The range of your resistor from all the way full to all the way empty. There are tabs to stop the arm from traveling too far off the resistor so do not bend them.

Consider the picture below. I'm showing two arm lengths but in the longer one I put a bend in it. The angles of both arms span the same 103 degrees (roughly) and they both travel the full range on the resistor.

Depending on where your new sending unit sits, height wise, it may be above or below the center of the tank. In my illustration it is above center. If your sending unit is actually below center, turn the picture upside down so you get the idea; it doesn't have to be exactly in the middle of the tank to reach full range.

I'm showing different length arms to illustrate the effects if yours is too long. It's easier to make a shorter arm reach full range. One way to make the arm shorter is to bend it sideways like a '?' (when you look down on it from the top).

[simplyconnected]

Here is a Rockauto.com picture of your sending unit:



The locating tabs that John mentioned are on the bottom of the mounting flange.

Notice two bends in the arm. If you bend both of them more, that will shorten the arm. Un-bending them will lengthen the arm. Good luck. - Dave