anybody have any ideas on this?!

[FabioB]

What started as a great ride in central Ontario on my '87 K100RS ended with my bike stalling 4 times on the highway, thankfully as I was closer to home. Each time occured while in 5th gear and doing about 110-120km/hr. :banghead The engine cranks over fine but no ignition. After wainting about 10-15 mins, it finally started. The last time though, I jump started it before i came to a stop. This 4rth time happened about 4km from home, and I finally made it. Could this be an easy fix before I call my dealer to book an appointment? Thanks to those who have an idea to help! :)

[Troutluck]

The first thing I would check is the wiring harness to the 'brain.' They have to be snapped/clicked in correctly or you can get intermittent problems like this. Not saying this is it, but it's an easy check.

[deilenberger]

Given your symptoms - it sounds suspiciuously like the Hall-Effect-Sensor failure that K bikes can experience.

To test for this - you can do it in the comfort of your garage - but you have to steal SWMBO's hair-dryer.. (or find a heat-gun..)

Remove any fairing parts that obstruct the bottom of the engine.. you need access to the T shaped cover on the end of the crankshaft - front of the engine.

Remove the cover (nothing will leak out.. but try to save the gasket..)

Start the engine and let it idle it is fully warmed up. IF it stutters and stops on it's own - turn the hair dryer to not-hot and blow it at the metal plate that was revealed when you removed the T shaped cover. Once it's room temp - or close to it - try starting the bike.

If it starts - now turn the hair dryer/heat gun to hot and point it at the plate. If it stutters and stops - you've confirmed the problem.

These usually fail "thermal" - as they warm up - they stop working. This progresses until finally they don't work at all.. but cooling one down will usually give you the clue as to what the problem is. And heating it up confirms it.

Cure - new HES sensors...

HTH, and thank Jeff Dunkle (Morton's BMW) for the diagnostic technique.. I'm just passing it on.. it's been useful to me.

[jamesbruce]

Had what sounds like a similar issue with my K1100 RS last fall. I checked the Hall-Effect-Sensor, swapped out the motronic computer with a friend with a fully functioning K1100 RS, to no avail. A replaced heat sensor which is inconveniently located behind the radiator did the trick. Best of luck.

[88820]

Had a similar problem earlier this year with an '85 K100. Checked connectors, heat sensor, and hall effect sensor, all were good. Finally checked the fuel filter, could not blow through it with mouth pressure. Replaced same, have had no problems since.
Hope this helps
Dave Rudzki

[Motor31]

I'd go with the fuel filter first and check for gunk in the tank. Is there a chance you got some bad gas as well? Look for water in the tank.