The world-famous Kawasaki Concours C10 fuel gauge resistor fix

One problem with the older Kawasaki Concours (AKA C10 model, for 1000cc engines) is the fuel gauge.  When full, the needle goes past F, which isn't too big a deal.  But as you ride the bike, after about 2-2.5 gallons are gone the needle drops halfway across the gauge.  NOT GOOD as this is a 7.5 gallon tank.  Then you ride another 80-100 miles and it drops to near empty, making you think you are about to go on reserve.  The problem is you have only used about 4.5 gallons-so you still have 100+ miles on the tank.  The needle now stays down near E as you burn off the remaining gas knowing the gauge is wrong.

Well, one of the great things about the Concours C10 is that over the nearly 30 years the bike has been on the road and the 20 year production run, lots of Concours Owners Group (COG) members have found fixes to one or another of the bike's issues.  One even has a business called Shoodaben Engineering (get it?) and like most on the board he's a great guy that probably gives away more knowledge than he makes on parts and mods.  Well in the case of the fuel gauge there are two fixes-the harder of the two involves messing with the actual sending unit in the tank.  No thanks.

The easier of the two is putting a 220 ohm resistor in the wiring from the fuel level sending unit to the gauge.  The easiest way to do that is on the pigtail from the tank to the wiring harness, where there is a blade connector easily available if you slightly lift the tank.  A clear step by step "how-to" is here and its what I used so I'll spare you a worse write-up by yours truly.  I even used the yellow zip-tie as you can see in the picture.  The second photo is a picture zoomed in on the pigtail-my work isn't as clean as in the instruction post, but it works fine.  BTW this picture was taken when I had the tank off the bike for another project-you can do the fuel gauge resistor mod with the tank bolts removed and the tank propped up like in the post. 

I was able to give some of the remaining resistors away on the COG Forum, as the whole pack probably cost 2 bucks (if that) and would have soon gotten lost or damaged in my garage.  I rate this project as a 2 out of 5 for difficulty as you have to remove the seat and the tank bolts at a minimum (removing the right side cover may help if your pigtail has dropped down).  For a California bike, any time you mess with the tank bolts you've got to clear out the hoses, adding to what would otherwise be a simply project.  Since you don't have to remove the pins in the pigtail connectors, even a non-electrician can do this mod.  I hate doing electrics but found this to be do-able.

If anyone reading this post has a Ninja 900 or Ninja 1000 from the 80s, I'd like to hear if their gas gauge has the same issue and if this fixes it for the sportier sister (as saying she was "faster" would be impolite!).