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1990 k75S quits running in under 2 miles

arbogast123

New member
I have a 1990 k75s it starts fine runs perfect take it for a ride and anywhere from between .5 to 2 miles it instantly shuts down all the electrical is still operating it will not restart leave it sit for awhile it starts up and runs fine drive it again the same thing . any ideas??
 
I have a 1990 k75s it starts fine runs perfect take it for a ride and anywhere from between .5 to 2 miles it instantly shuts down all the electrical is still operating it will not restart leave it sit for awhile it starts up and runs fine drive it again the same thing . any ideas??

It sounds very much to be temperature related. That is, something is warming up and when warm/hot causing the failure. It very easily could be the HES (Hall Effect Sensor) but these failures are rare on classic K bikes.

It also could be the ignition module mounted under the fuel tank on the frame backbone.

It also might be that a connector in the wiring harness is going "open" when it warms up.

It is possible also that the connector where the fuel tank plugs in to the main harness is losing continuity, or that there is a temperature related failure in what is called the fuel gauge inside the tank which passes power to the fuel pump. This type of failure can be identified by placing your ear just above the open fuel tank lid and listening for the fuel pump coming on for a few seconds if you just stab the start button.

I would check for spark the next time it fails. The very easiest way to check for spark is to use a timing lite with an induction pickup that simply goes around a spark plug wire. Three screws allow the coil cover to be removed giving access to the three plug wires at the coils.

This will separate a possible ignition failure from a possible fuel delivery failure.
 
Welcome to the forum! I'm sure you'll get a good checklist of things to pursue.
 
Welcome to the forum!
I will add a bit to your title- for clarity.
Good luck.
Gary
 
Sounds familiar...

I had a similar problem with my K75C a few years back. It turned out to be that the FI plug under the seat was just loose enough to get a bad connection intermittently. It's an easy thing to check.
 
1990 K75S quits running after .5- 10 miles

I am back and looking for help! I have the 1990 k75s that quits running after .5- 10 miles I have installed a new fuel pump and filter, it did not help. I put the bike on the center stand, put a floor fan IN front of it and ran it at 2500rpms for 25 minutes no problem. So why does it quit when I drive it????[/I]
 
Try opening the fuel tank lid while riding. It is possible that a clogged vent is creating fuel flow issues.
 
You may have already checked this but it’s easy to think you have this plugged in well when it’s not.

On the left side behind the side cover is a large plug that plugs into the electronic fuel injection module. There’s a spring clip that keeps it in place. Try removing it all of the way and then replace it making sure that it locks in place. Sometimes if these aren’t locked in place, either vibration or heat can cause the plug to loosen and stop making contact.

Good luck.
 
How exactly does the bike quit? Suddenly, as if the key had been turned off or engine cutoff switch flipped? Or does it begin to run “fluffy”, like it’s rich, then stall out? Will the bike restart immediately after it shuts down, or does it need to sit a while first? A good description of the exact repeatable symptoms will help narrow things down. Your problem could be anything from a bad cutoff or sidestand switch to a failing coil or bad temperature sensor. Or, something as simple as a wire that has chafed through.

Best,
DeVern
 
Arbo,

Please do not start a new thread for the same problem on the same bike. Keep it all together with your original thread so people can follow. When you have a different problem or if it is about a different bike, then start a new thread.

I have merged this thread with your previou on on this subject.

There are many things that can cause the problem you are experiencing. Dirty ignition switch contacts, dirty kill switch contacts, Hall effect sensor going bad, bad connection between fuel pump and wiring harness either at the fuel sensor plate or the tank wiring connector. You do not have a sidestand switch on your bike, so don't worry about that.

Does it feel like someone turned of a switch or does it feel like it ran out of gas? The answer to that will direct you where to look first. Does it immediately start right back up or do you have to wait a bit before it will restart? That answer will also direct you where to look.




:dance:dance:dance
 
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