Fuel Gauge Sender

[natemoen]

The fuel gauge sender I have kinda works. It's really slow to respond and isn't super accurate. It's not even consistently off, sometimes its high sometimes its low.

I have my tank off and pulled the sender out. Is there anything I can do to clean the thing up and just tighten the thing up so it works better?

[bikerphil]

Never had to fix one (yet), but I'd think cleaning it up good with some carb cleaner and then testing with an ohm meter per service manual would be a good start. If it checks out fine, there might be a problem with the guage connection.

[crazy steve]

That's not un-typical operation for these; that's pretty much how mine worked from the day the bike was new. The only thing it was consistant on was it would read empty well before I had to switch to reserve. I always felt the gauge was more of a gimmick than a useful instrument...

[bikerphil]

Steve, my guage has always been pretty accurate, yes a little slow regestering but always seems to work fine.

[crazy steve]

Phil, mine always worked, but accuracy was never it's strong suit; when it read empty, the amount of gas I would put in could vary by nearly a gallon. I found the trip odometer much more useful...

[motoman]

Those sending units CAN be made to be accurate if all else is working properly including electrical. Clean up resistor contacts and make sure arm is riding firmly against contacts. I filled my Venturer tank half of its capacity, set back on bike with sender plugged in and observed where level showed on gauge. Removed tank, stood on end, removed sender and slightly bent float arm, reinstalled sender, mounted tank, plugged in and repeated till gauge indicated half a tank. Only had to repeat process once. Now when full, shows a needle width above full and when having to go to reserve shows a couple needle widths above empty mark.......results may vary, but worked in this case.

[bikerphil]

Little story about the guage on my 79F... My guage stopped working in '90 about a year after I got the bike. It turned out to be a broken winding in the guage. There was a thin wire that I soldered back together to get it working. After the repair, the guage was now super slow regestering but still accurate. My guess is the solder created more resistance on the winding, slowing the guage down more. About a year ago, I had my tach apart for repairs and I swapped out the fuel guage with another one I had. Now the guage operates much quicker. Hmmm... one might be able to tweek the fuel guage winding for a faster operation!?

[ManagerMike]

The slow response time is inherent to the fuel gage as a part of the tach cluster, it is known as an anti-slosh feature. Don't want your gage wagging like a dog's tail as the fuel sloshes around in the tank, you'd never know how much fuel is in there. Modifying the winding won't make the gage any faster or slower, it is just a simple variable resistor.
Yes you can clean it up with either a solvent or a VERY fine abrasive, say, 1000 grit. Tightening it will only serve to make it stiff, as long as the brush is in full conact with the winding, you're good.