K75S - Will not start but RPM gauge registers RPMs without engine

My 92 K75S will not start. I found an accessory wire on the positive battery terminal intermittently shorted to the battery hold down bracket. The battery seemed to be dead. When checked without load it showed 12.76 volts. When the ignition key is turned to "on" position and before touching the start button, there is a very low sound coming from under the gas tank (perhaps in the relay box) and the RPM gauge goes up as though the engine was running. Lights do not come on.

I installed a different battery. Same thing occurred.

I charged both batteries and reinstalled one. I turned on the ignition key and the lights came on. I pressed the starter button and everything went off (cluster lights, headlights, clock, and no starter action). I released the start button and everything stayed off except the clock. I disconnected the negative battery terminal and I believe I heard a relay release. Then I reconnected the negative battery cable and turned on ignition key again. The cluster and headlight came on. I pressed the starter button and the starter engaged and I believe the engine would have started if I had allowed it to start. Everything looked normal.

I had this or a similar issue once last week and it appeared I had a bad battery. I tried to jump it off and it would not turn the starter. I left the bike at home and drove the car. I came home from work many hours later and tried again. The engine cranked as it is supposed to crank. Any ideas? It seems like it might be a relay issue. Has anyone experienced this behavior?

Ed

I'd check your starter brushes. If they get badly worn and out of spec it produces these symptoms.

anglojaxon said:

I'd check your starter brushes. If they get badly worn and out of spec it produces these symptoms.

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Actually, it's when the brushes and/or comutator get dirty. Usually all that's needed is a cleaning. Either way, it's time to disassemble the starter.

Scroll down to the starter section:http://ibmwr.org/ktech.shtml

Thanks gentlemen. I will clean the starter tomorrow. It was two wheels with pedals today!

Ed

Ed,

While dirty starter brush/comutator seems the most likely candidate (clean thoroughly even if they LOOK clean), if it doesn't solve the problem, a thorough cleaning of the inside of the ignition switch and the kill start button may correct things. Check the link I posted for directions to clean ignition switch.

98lee said:

Ed,

While dirty starter brush/comutator seems the most likely candidate (clean thoroughly even if they LOOK clean), if it doesn't solve the problem, a thorough cleaning of the inside of the ignition switch and the kill start button may correct things. Check the link I posted for directions to clean ignition switch.

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Hi Lee. I cleaned the starter good and put everything back together. I learned that one of the batteries is malfunctioning. I'm planning to have it tested tomorrow. Both batteries are the same brand and purchased at the same time. The battery seems like it charges, but it is not functioning properly. Even though it is showing full charge at 13.01 volts, it will not provide enough amperage to turn on the lights, and I get the noise in the relay box and no operation of the starter. The second battery appears to be good and it operated the lights and starter fine, but the engine would not crank. I'm trying to figure out if I left something disconnected. I can't think of anything. I had to put it away for the night. Since i had a battery issue and perhaps an intermittent shorted positive wire to ground, I'm suspecting a fuse, but did not have time to look. I will check the ignition switch and kill button also. I have an idea that the shorted wire has messed something up, but not sure what.

I forgot to mention that I finally put new brushes in the alternator to deal with what I was suspecting to be a low voltage issue causing my ABS to disengage and require resetting over and over when going very slow at low RPM. This starting problem began before I changed the brushes.

Starter relay bad?

While the starter relay usually goes bad from low voltage (the contacts weld together and the starter runs constantly) it sounds like yours is not engaging properly.

I cleaned the ignition switch and kill switch. Engine still does not start. Starter grinds away normally, but no start. I checked all the fuses known to me and they are all good. I did have a battery tested and it does have a dead cell, but that is not the one currently installed which tested fine. SO, I have a good charged battery, no blown fuses, clean ignition switch, clean kill switch, new alternator brushes, a clean starter commuter and good brushes, and still no sound of the engine attempting to fire. I will remove the gas tank over the weekend to get to the relay and test it. This seems really strange. Are there any fuses other than the fuse block above the coils?

Open the gas cap and push the flap open. Listen as you push the starter with the key on. Do you hear the fuel pump running for a second or two after you release the starter button?

Check, clean and make sure the computer is plugged in securely.
Do you have spark?
Are the plugs wet? K75's are notorious for fouling the plugs.

I had that problem once, turned out to be a loose ground at the ground strap from the battery to the motor.

98lee said:

Open the gas cap and push the flap open. Listen as you push the starter with the key on. Do you hear the fuel pump running for a second or two after you release the starter button?

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Fuel pump is not running. Now to trace that down.

yankeeone said:

I had that problem once, turned out to be a loose ground at the ground strap from the battery to the motor.

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I checked the ground wire and it is solid. No issues.

The good news: It is running now. The bad news: I have no definitive answer as to why. I disconnected the fuel pump wire at the connector under the gas tank and connected again. No change. I did it again and moved the wires around in the bundle including the connector and tried again. It fixed it.....or did it. It is running for now! Thanks everyone. I got some preemptive maintenance out of the challenge and that is good!!

73s

Ed

Examine the bundle of wires that you moved. Look for worn insulation. Electrical problems very rarely "go way". You moved something involved with the cause of your problems, and that "fixed" the problem. Until you can find what's failing and fix it, plan on being somewhere between Boone and Sanford when the lights go out again.

Hi,

Just dropped in for a moment. The RPM gauge registering RPMs without the engine running - to me - points to one thing. The Hall-Effect sensor is going kaput. The wiring on it deteriorates and eventually starts sparking between the wires. That gives the symptom of the tachometer reading when the engine isn't running. The Hall-Effect sensor is responsible for: (1) tachometer signal (2) signal that turns the fuel pump on (3) trigger for the ignition system.

Usual failure starts when the bike is hot - and it just stops - then when it cools down it runs again. In this case it sounds as if either the sensor itself has gone bad or the wiring from it to the ignition module under the tank has gone bad. That module is under the main frame tube right behind the steering head. Were the wires you moved in that area?

Just a few thoughts.. hope they help.

deilenberger said:

Were the wires you moved in that area?

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No, I did not have the gas tank off and only moved the wires at and near the connector for the fuel pump which can be reached at the right rear side of the gas tank.

One new issue I just noticed is that the oil light does not light with key "on" before pushing the start button. It may have nothing to do with it.

Ed