Here's a discovery that may help others. Recently was test riding an '87 K100 after some work and the bike suddenly quit. (Luckily only a few steps from the shop!) Checked for the sound of the fuel pump running, heard nothing. Pulled the pump from the tank and gave it power to the terminals and it was working. Started working backwards to find where the power had stopped. Found the post on the base of the fuel sender where power coming into the tank splits in several different directions. Sure enough, the power wire for the pump had broken away from the post. The wire was looking old and I didn't figure that trying to solder a new wire to the dirty old post would work too well so I drilled a small hole in the sender base and put a new wire through the hole. I tapped into the green power wire that is part of the 4-wire harness running up to the sender. The hole in the sender plate was sealed up with some JB Weld on both sides. Says on the package it stands up to fuel after curing. So far it has no leaks. A new O-ring on the sender plate, a new filter, some new ring terminals on the fuel pump wires and it is running again. Also at some point in the bikes life the original fuel pump had been replaced with another of generic type and had no strainer underneath. (The tank was loaded with crud so cleaned that out. I'm actually amazed the pump was still working. Ran some clean varsol through the pump.) NAPA has car fuel strainers for under $10. Made an aluminum neck-down adapter on the lathe to hook the strainer to the pump. The world is now a beautiful place. Now to fix that intermittent speedo...
