Hello, when I press starter buttonof my K 100 1983 cant hear the click and pump. Sometimes I have to repeat 3 - 4, or 10 times (or never) to hear click pump and sprag sound. After I can start the engine. What is reason: battery is full and tested, starter clean and OK? Could it be ground of starter relay. I tried with the changing of fuel relay but nothing changed.

Regards Nino

Have you checked the starter button? This could be the culprit and it has to be cleaned.

hmmm ...could it be the igniton switch nino ? there are lights on the instrument cluster when you turn it on ?.....other than that...could it be the actual starter switch contacts ?
you may need to undo the right hand side switch assembly ( 1 screw) and test it ..or bridge it with a piece of wire .

Yes, I tried with another starter button and it was the same. I saw the article in K tech page by Richard Merck about additional grounding of starter relay. What do you think about it, Bert?

Charlie, where is ign. switch. I have all lights on intruments, and replaced right hand switch, and problem is still here. Could it be sprag clutch?

nino ...if you have lights on, part of the ignition switch is working fine.
but it is the switch where you put your key ....in the dash rubber thingy ...it looks as though there is a number of wires comming from it ..one of which goes off to the starter switch and load shed relay .

from memory the starter button also goes through the clutch lever switch it might be worth checking that out too .....i could imagine that if it was faulty that might contribute .

dont know if there is a sidestand switch as well on your model ....might be worth a quick look ?

but like all things electrical ....i suspect some corrosion somewhere, in one of the connectors .

hope this helps

@@note : there is a circuit diagram that bert has done up here in the forum (fantastic work)....but you might have to add a post to the new members section before you can access it in the downloads area .....or search for "wiring diagram"

Ok, I checked clutch lever switch. Its OK. I ll check ign. switch. There is no sideswitch on early K

Thanks

Here is the starter diagram...



You should also check this page. It may help you to find the gremlins.

Bert

Thanks Bert, I already red most of your articles by Google. wiring scheme is very clean and easy to understand. I ll start with ignition switch and connector under the tank

When it does not work is the neutral light working? The neutral light is controled by the gear position indicator and if the light does not come on then the starter button circuit is not complete and so no start.
That problem can come from a faulty gear position switch with water in it or a faulty printed circuit board inside the instrument cluster. I was led a merry chase by a crook circuit board that usually worked when the engine was running but not when stopped. It was very intermittent and had similar symptoms.
It can be overridden by pulling the clutch in and then it starts.

Everything looks fine, all light came on, but no enogh power on start

nino ...we have seen many times that the starter relay becomes corroded on one of the contacts due to arcing ...many have replaced this relay .......
i think it would be important to also mention that the brushes on the starter motor also are a sorce of failure , in addition to causing some eratic electrical problems .

i have myself recently purchased a replacement set of brushes for exactly that reason , and now keep them in a plastic bag under the seat .

i have seen recently in this forum that at least one member has had an issue with the large power wire from the battery to the starter relay ....aparently the wire connections had become faulty for some reason.

in any case it would be a good idea to test these cables and see if there is some way of bypassing the relay ...maybe a wire bridge accross the starter relay from the battery and see if the starter turns correctly.

nino wrote:Everything looks fine, all light came on, but no enogh power on start

I would now look for faulty connections in the starter circuit.

1. Starter relay contacts are a problem and do fail. often you will find a contact has coroded badly or even fallen of the switch itself. Solution is replace the relay. Bosch make several relays that will do the job but the one that is best has a small resistor inside the case which helps prevent arcing at the contacts.
   
2. Starter motor brushes but you say that has been seen to and is OK
   
3. Cables connecting from battery to relay and from relay to starter are possibly coroded at the connector points Solution new cables and make them bigger as the original ones are only just adequate for the job.
   

Thanks Charlie and Freak. I am on trip by car. I ll check every connector
when back, but genrally my wires are pretty good

Problem solved
It was a bad contact of fuel pump. Pump didnt starit or started badly. When I fix the contact not problem any more

Thans for help

yay.....good result nino .......happy riding