Another K75 starting issue

[TXKbike75]

Hello all,

This is my first post on this forum.  I purchased my 1988 K75s about two years ago, it had been a rock solid boringly reliable bike for nearly 8k miles.  Before Christmas it did the weird sputter and die thing, and has been a project ever since.  I have yet to actually get it running, and work on it in my spare time.  I have been going through the forums and the diagnostics.  Before doing any electrical related work, have appropriately disconnected battery and been very careful with main brainbox. Before cleaning the starter I had spark, heard fuel pump, starter kicking over, had all the cluster lights.  Before it died, I replaced the cranckcase breather hose, and the clutch cable, and had just changed oil.  Since it died, I've cleaned up plugs, even replaced with new correctly gapped plugs.  I've changed airfilter, battery, coils and plug wires, verified I have spark, cleaned ignition and starter switches as well as the starter itself.  I have a new fuel filter that I plan to replace as well.

What my current issue is, is that until I removed the starter and cleaned and reinstalled it, the instrument cluster, fuel pump and starter all worked, that is the bike would at least act like it was going through the starting sequence and would turn over.

After removing, cleaning the starter, and reinstalling it, and cleaning any visible contacts in the wiring and reconnecting them, I turn the key and hear a click in the relay box, but no fuel pump, instrument lights, or starter action.  I have hi/lo headlights, tail light, turn signals and dash indicators, and horn.

I have checked/rechecked starter and all contacts/grounds.  How does it go from turning over etc, to this condition?  This is incredibly frustrating and teadious, and am close to calling it quits and looking to replace it. As a last resort, I do have the lead on a decent mechanic, but am reluctant to throw much more $ at this thing.

Any thoughts to at least help me get back to my cranking condition would be appreciated.

Thank you,

[Inge K.]

Welcome TXK!
Check fuse #1, if the fuse is OK....check if power is present.
If no power.....the kill switch would be the next to suspect.

[WayneDW]

Hello.
Have you been to this site and printed his step by step get your K-bike to start instructions?:
http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/bike-wont-start1.htm

HTH, I can understand your frustration and it'd be a shame if you have to give up.

Where are you located?  Maybe someone is close by who could give you a hand.

[kioolt]

I've always been willing to help someone if I was local.  Electric troubles are my specialty.  I worked as an industrial electrical troubleshooter for over 35 years.  Are you near Baltimore?

[rbm]

With a login TXKbike, I'd hazard a guess -- Texas???

[TXKbike75]

Yes, gentlemen, that is correct I am in Texas right outside of Austin.  Wayne, yes I did download that and it has helped me quite a bit.  I am sure for someone with more experience, this would be sorted out sooner.  Being new to the Kbike, its a learning curve.  There are things about this bike that do make it easier to work on than previous bikes.  Until recently, I have had only kind things to say, and was a strong proponent of BMWs.  My opinion reached a colorful point this weekend, and fortunately it was kept mostly to myself.  Surely my little K is not deserving of my scorn.  It could use some TLC, I don't want this to be our parting point, yet I don't want to start sinking funds into it.

Taking a look at the fuses again, and looking to replace the kill switch, maybe its worn enough that its causing a short.

[mjydrafter]

Yes, gentlemen, that is correct I am in Texas right outside of Austin.  Wayne, yes I did download that and it has helped me quite a bit.  I am sure for someone with more experience, this would be sorted out sooner.  Being new to the Kbike, its a learning curve.  There are things about this bike that do make it easier to work on than previous bikes.  Until recently, I have had only kind things to say, and was a strong proponent of BMWs.  My opinion reached a colorful point this weekend, and fortunately it was kept mostly to myself.  Surely my little K is not deserving of my scorn.  It could use some TLC, I don't want this to be our parting point, yet I don't want to start sinking funds into it.

Taking a look at the fuses again, and looking to replace the kill switch, maybe its worn enough that its causing a short.

If you have an OHM meter you should be able to test the switch for continuity.  I would try this before sinking any more funds into it... :yes

Also work the kill switch back and forth a few times through each position and see if it won't go at some point (which would lead me to believe that cleaning the contacts in the switch might have her running again).

[TXKbike75]

If you have an OHM meter you should be able to test the switch for continuity.  I would try this before sinking any more funds into it... :yes

Also work the kill switch back and forth a few times through each position and see if it won't go at some point (which would lead me to believe that cleaning the contacts in the switch might have her running again).

I have a multi meter, how would I check the switch for continuity?  I did just clean the contacts and reassembled it.

[Inge K.]

Under the tank you find the connector to the RHS switch assy, on that connector you got a green wire
and a green/yellow wire.
With ignition on, check the voltage at both wires...you should read the same voltage at both.
If you read much lower voltage at the green/yellow wire, your kill switch (or it's connections)
is the problem.

[mjydrafter]

to add to Inge's post.

When you have the hot end tested, you can test the dead end of the same plug, the switch end.  With the kill switch in the run position you should have continuity or zero OHMs (same as when you touch the leads of the meter together) between the two wires (green & green/yellow).  With the switch in the kill position, you should not have continuity or infinite OHMs.

If your meter is nicer it might have a continuity setting on it, it will beep if you have continuity.

Fixified thanks to kioolt :yes

I didn't have my meter here in front of me. :2thumbup:

[kioolt]

to add to Inge's post.

When you have the hot end tested, you can test the dead end of the same plug, the switch end.  With the kill switch in the run position you should have continuity or infinite OHMs (same as when you touch the leads of the meter together) between the two wires (green & green/yellow).  With the switch in the kill position, you should not have continuity.

If your meter is nicer it might have a continuity setting on it, it will beep if you have continuity.

You should have said.  With the kill switch in the run position you should have continuity or zero OHMs (same as when you touch the leads of the meter together) between the two wires (green & green/yellow).  With the switch in the kill position, you should not have continuity or infinite ohms.

[TXKbike75]

So for this type of testing, do I use both the red and the black probes, and if so, where do I place each one to get the readings?  On the ohm meter setting what setting do I use?  Mine shows 200, 2000, 20k, 200k, and 2000k.

[mjydrafter]

So for this type of testing, do I use both the red and the black probes, and if so, where do I place each one to get the readings?  On the ohm meter setting what setting do I use?  Mine shows 200, 2000, 20k, 200k, and 2000k.

Yes you would use both of the probes.  I could be really wrong here, but it may not matter which setting you use, since we aren't measuring particular OHMs, just checking continuity.  Continuity is more of an on/off kind of deal and I'm probably way over simplifying it.

My little GB analog meter has the OHM setting as x1k.  So I would try the 2000 setting.  Test it by touching the probes together, it should go to 0.  Then if you want test a good piece of wire, touch the probes at both ends, it should be 0 like touching the probes together.

Hopefully kioolt can check/correct any mistakes I've made.

Signed,
Not an electrician. :yes

[Inge K.]

Voltage drop is a better metod to use, than measure the resistance....when checking the switch.

When measuring resistance a very small current is sent through the switch,
and if it's only a very small spot making contact....it would look like it's OK (zero ohms).

When using voltage drop metod you put the normal load through this same spot
which then wont be able carry the current flow through...the resistance goes up, and the voltage drops.

[TXKbike75]

Well if I tested correctly, it looks like the starter switch might have something to do with my problem, as it seemed to vary a little while pushing the starter switch.  Think my keyed ignition switch might have something to do with it too.  I disassembled/reassembled it and now at least have all my cluster lights, fuel pump and turn over working again.  Also replaced fuel filter.  There were a couple times after I did all this that it acted like it wanted to fire off.  It's getting gas, plugs are wet.  Feel like I'm closer, but still not there.

[TXKbike75]

Thank you all for the help that you have given me.  I finally got the bike running.  Not sure exactly what it was, but I found working ignition, start/kill, and clutch interlock switches cheap enough, that I replaced them all.  Once everything was reassembled, turned key, pressed the switch and vrooom fired right up!  I picked up a spare clutch interlock switch as well, since it much cheaper than the dealer, and will start having some spare parts on hand to avoid future problems. 

I'll eventually test out all the replaced parts, but was happy to have it going for now.  My guess is, the keyed ignition switch was also one of the culprits, since it did have a crack in the casing, and was no longer holding together tightly.  Given the registered miles, could've been the clutch switch as well.  In any event, I got to know the bike quite well, and did some maintenance that needed to be done anyway. 

It also now has a new crankcase breather hose, fuel filter, air filter, and clutch cable.  I adjusted the clutch and seems to shift way better than it did prior to this point.  Nice and solid and smooth, not gummy like before.  Also don't see engine oil covering parts of the underside.  Didn't know where that was coming from, and thought it had to do with running Mobil 1 synthetic.

Next projects, spline lube, fuel level float, luggage rack/top case mount, brake bleed, radiator flush, and seat repair.

Thanks again, ride safe.

[K75RT Keith]

Check your grounds are clean and connected, make sure the fuel pump connector is properly connected, make sure the kill switch is in the "run" position.  Does the headlight dim when you hit the starter button?