Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[hogheritage04]

Has anybody had any problems with the fuel guage?  I know these are infamous for not being accurate, but I noticed that the guage never seems to move off of full.  Last time I fueled up, had about half a tank, (put in about 3 gallons), and the guage was still on full. [smiley=nervous.gif]  Has anyone that has had this problem been able to have it adjusted?  Would appreciate any input so I can go to the dealer armed with some knowledge.

[Midnight Rider]

Only thing I've observed on mine is that it moves to half a tank "normally" then drops like a friggin' rock, so you'd best be finding a gas station shortly after is shows 1/2.  I'd say yours was defective, or at least the sending unit.

[ultrafxr]

Only thing I've observed on mine is that it moves to half a tank "normally" then drops like a friggin' rock, so you'd best be finding a gas station shortly after is shows 1/2.  I'd say yours was defective, or at least the sending unit.

Yeah, my '99 Ultra did that and so does my CUSE.  Must be the nature of the beast.

[Fired00d]

Only advise I can offer is forget looking at fuel gauge, and use your trip meter instead (5 Gallon Tank X 35 - 40 MPG = 175 - 200 Highway Miles) . It must be something about gravity on these bikes as it takes forever to get to half full then gravity hits it, and it drops faster then you can shake a stick at it.

 [smiley=pumpkin.gif]
Ride Safe,
Fired00d
 [smiley=fireman.gif]

[jdracing]

Only thing I've observed on mine is that it moves to half a tank "normally" then drops like a friggin' rock, so you'd best be finding a gas station shortly after is shows 1/2.  I'd say yours was defective, or at least the sending unit.

OK, mine does the same thing, but I've got a theory about this--so here goes: the top 1/2 of the tank holds substantially more gas than the bottom 1/2 because of the cutout for the frame backbone the tank sits on.  When the float is up at the full level, I'd guess maybe 65-70% of the total volume of gas in the tank must be burned through before the float gets to the 1/2 way mark.  The last 30% of the gas keeps the float at about the 1/2 way level because of the displacement caused by the hump inside the tank.  

The sender reacts in a linear fashion as the float drops, but the relationship between the amount of fuel in the tank and the float height is not linear throughout the entire range.

By the way Hogheritage, sounds like your float is sticking or the sender is screwed up.

      

[lucky1]

My float was stuck when new, never moved, even when it ran out of gas! Took the dealer four times to fix. Now I don't trust it past half tank. Good Luck.

[grc]

Has anybody had any problems with the fuel guage?  I know these are infamous for not being accurate, but I noticed that the guage never seems to move off of full.  Last time I fueled up, had about half a tank, (put in about 3 gallons), and the guage was still on full. [smiley=nervous.gif]  Has anyone that has had this problem been able to have it adjusted?  Would appreciate any input so I can go to the dealer armed with some knowledge.

hogheritage04,

Most fuel gauges with a similar design, even in cars, are not linear in response at the "full" end of the scale.  There is a mechanical stop built into the sending unit that keeps the float from banging against the top of the tank, so the gauge doesn't move until the level drops low enough to let the float actually "float".  I have to say that the sending unit H-D uses in these bikes is probably the least linear and least accurate of any gauge I've ever seen, going back to the '60's.  Two issues that have been reported by a few folks is the float actually being hung up on the in-tank fuel line or the float rod support being bent, both of which could cause the gauge to never drop below a certain value.  Does your gauge reading drop if you wait until the tank is nearly empty before filling up?  If not, this would be the first thing the dealer should check.

Yes, you can have the gauge adjusted, but it won't be accurate at both ends of the scale.  Since "full" doesn't mean anything, I suggest having it adjusted so that you have 1.25 - 1.50 gallons of fuel at 1/4 tank on the gauge.  This is the important part of the gauge, the part right before you have to get off and push.  The low fuel light seems to come on at 3/16, and this should correspond to at least 0.9 gallons remaining.  Now for the fun part:  H-D has a short diagnostic routine in their manual to verify the electrical function of the gauge and of the sending unit.  If the dealer performs the tests and one of the components fails, he will just replace that part.  If you get lucky, you might actually get a combination that is relatively accurate at the bottom half of the scale.  If not, then a manual adjustment of the float arm could be done to alter the gauge reading.  Very few dealers are going to have someone willing to take the time to do this, since it is a trial and error method that can be very time consuming.  H-D pays a flat rate for warranty repairs, and the technician will wind up eating the extra time involved to "tweak" the sending unit.

Check out this thread from the Electra Glide forum for additional info.  http://flhrsei.org/cgi-bin/yabb/YaBB.cgi?num=1118059114/0   If you read all the way through, you’ll find an alternative method to make your gauge reading adjustable by adding a variable resister to the circuit.  Worked fine for me, after the dealer didn’t fix squat, and now I have a gauge that is pretty accurate from empty to about 5/8 full.

Jerry

[Midnight Rider]

Good Hypothesis, JD   [smiley=xyxthumbs.gif]  Makes perfect sense to me...is it, in fact, a float and not an electronic sensor?

[grc]

OK, mine does the same thing, but I've got a theory about this--so here goes: the top 1/2 of the tank holds substantially more gas than the bottom 1/2 because of the cutout for the frame backbone the tank sits on.  When the float is up at the full level, I'd guess maybe 65-70% of the total volume of gas in the tank must be burned through before the float gets to the 1/2 way mark.  The last 30% of the gas keeps the float at about the 1/2 way level because of the displacement caused by the hump inside the tank.  

The sender reacts in a linear fashion as the float drops, but relationship between the amount of fuel in the tank and the float height is not linear throughout the entire range.

By the way Hogheritage, sounds like your float is sticking or the sender is screwed up.

      

jd,

You could very well be right about H-D using a sending unit with a linear response curve, even though the shape of the tank should dictate a non-linear curve.  It would fit right in with some of the other peculiar stuff they do.  The sad part is that it wouldn't cost a penny more to do it right.  BTW - the following resistance values (measured between the yellow/white wire from the sending unit and ground) come from the H-D manual:  Full - 7 to 14 ohms,  Half - 30 to 38 ohms, Empty - 74 to 95 ohms.  Note the wide tolerances, especially at empty.  Can't imagine why the gauges are inaccurate.

Jerry

[jdracing]

Good Hypothesis, JD     Makes perfect sense to me...is it, in fact, a float and not an electronic sensor?

Thanks TC.  Oh yeah, it's a float alright.  I've had mine out twice and it's a quite a challenge to get it out of the tank without screwing it up.  The sender mechanism is hinged so that it will straighten out somewhat to help squeeze it through the opening, but it's still a struggle because of the size and angles compared to the opening.

[jdracing]

You know, Jerry, from those resistance values it sounds like they were trying to make it non-linear--there's much less of a resistance increase through the top 1/2 of the range than the lower 1/2.  That suggests that the gauge should be less sensitive to fuel level drop on top, and more sensitive on the bottom.  Doesn't that seem backwards since you'd want it to be more sensitive on top where the level drops slower and less sensitive where it drops faster?  In other words, is it non-linear in the wrong direction?  Or do I have it backwards?  

[Midnight Rider]

If they ran those values through a device that had an algorithm (sp) to equate a level with actual volume in the tank at any particular level, then you could make it work.  Otherwise, it's an educated guess based on an inverted relationship as the tank gets smaller towards the bottom, and the volume of liquid getting smaller all the time because of the shape.

Damn, it's too late to be thinking about this chit  [smiley=huepfenlol2.gif] [smiley=nixweiss.gif]

HD isn't the only one though....my Duc fuel level indicator is electronic (at least the "gauge" is), and it starts blinking at me when I know I've got at least a third of a tank...guess what?...I use the trip odometer    So the Italians can't get it right either.

[amigo Jorge]

Only advise I can offer is forget looking at fuel gauge, and use your trip meter instead (5 Gallon Tank X 35 - 40 MPG = 175 - 200 Highway Miles) . It must be something about gravity on these bikes as it takes forever to get to half full then gravity hits it, and it drops faster then you can shake a stick at it.

 [smiley=pumpkin.gif]
Ride Safe,
Fired00d
 [smiley=fireman.gif]

That's exactly what i do........check the trip meter....... [smiley=drink.gif]

[hogheritage04]

Thanks to all for the info.  It seems that I'm not the only one who has the problem. I'm not sure if that makes me feel better or not [smiley=nixweiss.gif]  I do use my odometer as the fuel guage is useless as far as I'm concerned.  It's hard to believe that a bike that costs as much as these Screamin Eagles don't have a useful gas guage.  Again, thanks for all the inputs. [smiley=banana.gif]

[Midnight Rider]

Hog...there's comfort in knowing you have company  Basically, the gauge works OK to half a tank, so at least it's not totally usless...at least it lets you know you better look at the odometer...sort of a "reminder" device    Like the air temp (or rain gauge  ), it's just there for looks.  Spun aluminum looks purdy though...