Hi All,
Im back on the road again after several years off!! No better way than to buy a K100 LT in England and ride it all the way to the south of Spain, 1442 miles over 3 days! I bought a 1991 model with only 43392 miles on it, ex Police bike, so fully serviced. The last service was 48 miles ago, but 6 years ago. Real good tidy bike.
All went well apart from the last day when after refilling, the starter wouldn't engage, nothing at all. I rocked the bike in gear and it started on the switch, after that no problems for the rest of the day. At home the next day the bike wouldn't start again on the switch, over the last 5 days it has either;
1) Made no noise at all when the switch is pressed,
2) Made a current sounding noise with clicks heard beneath the petrol tank and lefthandside panel,
3) Once started on the switch after rocking the bike in gear,
4) Always starts if you put it in 3rd/4th and bump start it.
Any suggestions please, I have read possible causes, and am thinking it may need a starter motor or an overhaul,
Regards,
Tiddy

Welcome to the forum Tiddy I see the guys have already helped in the other thread so you should be back riding very soon.

Welcome and good luck...

That problem you have is identical to the problem I had with mine last year. Everyone was really helpful with offers of parts and everything.

I went through many things but on the basis that you find your keys in the last place you look I can go backwards from when it first happened...

First thing you do: make sure battery is good and connections are good. I knew mine was good.....

Last thing I did: replaced the ECU up under the headstock. Got one from motorworks for £50 and cleaned up all the contacts with wet or dry 1200 grade paper used dry and fitted it. Never a problem since this was done. Was cheaper than paying BMW to test my one and at that point it was already suspect. I do not know if the problem was inside the unit or in the contacts but since the contacts live outside and the unit is nicely sealed up from the weather they are the more likely culprit. I opened the unit and it was like new inside and perfect. [note: a lot of the guys point to sensors etc as being possible suspects. They all feed into the ECU. Of course they are right and I suspect that a bad contact is read as a defective sensor meaning that replacing a sensor may not always work.]

Before that, took out starter motor, [battery out, disconnect wire, undo 2 allen bolts, and out she comes, easy] opened and cleaned it all out. It looked fine but did it anyway.

Before that: changed load shed relay [motorworks, small money]

Before that: changed starter relay [BMW, slow and expensive, decided motorworks in future].

Before that: cleaned all the earths under the gas tank.

Before that: removed and stripped starter motor, checked everything.

Before that: checked all the connections and made sure battery was good. It was.

I hope ths is some help. Its actually quite easy to do but I was on a learning curve.

Thats just the history of my K. Total cost of all the parts from I used would be max €100 including postage from motorworks....

When you are doing this replace the fuel lines [probably perished anyway] with longer BMW ones and you can simply disconnect the fuel pump and lift the gas tank instead of disconencting the fuel lines and access the electrical box under the tank.

Best of luck, a great bike.