Hi ,

I experienced a problem today I hope somebody can help me with . Was riding along when all of a sudden there was a complete power loss . Pulled over to find all dash lights working and fuses ok , but no starter when button pushed . Can anyone suggest what I need to start looking at ?

Thanks

Baz

One common problem: The plug of the fuel injection computer gets dislodged. You can check it, but your starter is not working and it doesn't need the FI computer to turn.

Last night, I just finished the diagram for the starter circuit with the real color of the wires.
Before having a look at it, you should put the bike in third gear and turn the back wheel of the bike (just 1/4 turn). Put the bike in neutral again, pull the clutch (even if you are in neutral) and try the starter (You may have a problem with the gear digital display or the small diode on the neutral circuit inside the instrument cluster).

The starter circuit is the easiest to troubleshout and if you find the problem, you may also find why the bike stopped running.

You said that you have dash lights, but does your headlight works? If not, it could be as simple as the main ignition switch being bad.




Click here to see the starter circuit

My ignition and lights were cutting out but I could fix it by switching off and on, so I cleaned my ignition switch (recently). Now I am having the ignition cut out occasionally but the lights and dash remain on. Switching off and on still fixes the problem. Not sure whether to re-do the ignition switch, it seemed pretty clean when I last finished with it.

The symptoms sound to me in order of likelihood like the ignition switch is playing up, or one of the the wires is not seated home properly on the bottom or least likely a broken wire inside the insulation sheath. When you cleaned it did you lubricate it and if so what with?
Regards,
K-BIKE

Hmm, no I didn't lubricate the contacts. I may have to go back in either way. Still, I'm having trouble seeing how this would cause new failures inside a week. Unless I'm wrong, it sounds like I may need a replacement switch.

Hi,
I was wondering if you had coated the contacts with silicone grease which is an effective insulator unless you can get metal to metal contact. I have heard of people having problems with contacts that spark and are coated with silicone grease getting intermittent connections. Not having personally had it happen (I don't use silicone grease on any electrical contacts so I guess I am unlikely to find out)

It is a pain having to go back in but looking at the diagram I can't see anything else that jumps out at me except the kill switch which would stop it. I know some people had trouble with the plug under the tank for the fuel pump which has pretty small contacts, non running fuel pump stops one promptly but that would not come back on by operating the ignition switch. When it is running does wiggling the switch back and forth a little cause it to prematurely stop? If it did I guess that would point exclusively to the switch contacts.
Regards,
K-BIKE

I am sure you have found it already but just in case this is the page where the ignition switch cleaning section of the downloads points to.http://www.easternbeaver.com/Main/Stuff/BMW_Tech/Ignition_Switch/ignition_switch.html

Regards,
K-BIKE

I didn't use grease and I expected the mild abrasion to keep the contacts clean. I was having issues with the kill switch and recently stopped using it during this issue, still, if I cycled the kill switch while riding the bike would just keep running.
Good link, no I hadn't seen that one. Pictures are good. Pulling the switch apart wasn't as bad as I thought. Without first having learned about the thumbscrew though I may have done it a little damage trying.

Can you bridge the kill switch with something else to see if that cures the issue?

That's what I thought, and at first I figured that something was cutting out with the kill switch and needed resetting by using the ignition switch, and I almost asked here whether that sounded possible until I remembered that I'd already tried using the kill switch on the move, just for kicks.Would I need to remove the tank to do this?I've noticed it sometimes happens after a bump. Usually I can cycle the key quick enough to not need to change down a gear and the key has always had an effect when I do.

I am suspecting a bad switch or a break in the wire inside the sheath to one of the wires to the switch or a bad connection at the plug where the wires join the main harness. If you don't cycle the key does it stall when it is running ? As I asked above if it is running does moving the switch back and forth cause it to falter not moving it far enough to switch it off just moved slowly almost up to the switch off point and back. If that causes a falter it is definitely the switch.
Regards,
K-BIKE

No, wiggling the ignition switch doesn't cause a miss, but the plot thickens. I know already that cycling the ignition switch recovers from a stop. Today I discovered that cycling the kill switch also recovers.
This makes no obvious sense, naturally, but I wonder whether the switching current surge is causing a small spark somewhere across some dirt in a connector somewhere.
A strange thing was that the second time it cut out while riding today, I flicked the kill switch and it turned off more (wasn't fully dead) then came on full when I returned the kill switch.
Next opportunity I'll remove the tank and use contact cleaner on every connector I can find, as well as cleaning the kill switch.

Hi,
If wiggling the switch did not do it I think the switch is OK and I incline to your surge theory.
I recommend DeOxit from Jaycar the best choice is to buy the kit with two glass bottles which look like ladies nail varnish bottles (I am sure that is what they were made for) each has a little brush in it and the two should be around A$25 or so don't get talked into anything else you want DeOxit made by Caig Laboratories. When you clean the connections don't forget all plugs and sockets as well as earths plus do the two big plugs on the Motronic (and ABS if you have ABS) computer(s) Do those and make sure they are properly clicked back home it is a common problem not to have them fully mated.
Do all the relays in the relay box as well as the plug connections to the ignition unit, air flow meter and air thermistor in the air box plus do the plug and socket to the fuel tank cable.
I certainly looks like you have narrowed it down a bit.
Regards,
K-BIKE

I'm doing an output shaft in two weeks, I'll see to them all then. Thanks for the suggestions.
I once used DeOxit on an old amp I was having issues with. It really was great stuff. I'll get some more. Cheers.

Good on you,
Let us know how you get on and consider taking some photos of the output shaft job!
Regards,
K-BIKE

I experienced this some time back. It was dirty contacts. The round connector under the seat was the culprit. It has round male female conns so I cleaned them with a drill Smaller than the hole and scraped the males. No more problems....Most failures are down to dirty contacts or frayed cables. A good check/clean/lubricate with petroleum jelly or vaseline will save a lot of pain. The loom is the weakest item on these bikes. Also the Kill/Starter switch get filthy and sometimes arcs out. My two pennyworth. Ajays