83 K100

I have an 83 model which has not been started for 14 years
When I push the start button the Starter relay clicks most of the time and nothing else happens but occasionally the starter engages for about 1 second
Been working through Bert's troubleshooting guide :
Battery voltage 12.33 volts
Ignition is ON and instrument lights work as expected
Green neutral light  in ON
Lower terminal on Starter relay 12.33 volts
STARTER BUTTON PUSHED
Relay clicks
Upper terminal nil volts
Continuity from starter button pin 86 of starter relay,  black /green wire 10.04 volts
Continuity from starter button pin 85, red/brown wire 10.04 volts
This is each time the button is pushed
Sometimes the starter engages but for no more than 1 second and then just stops, when this happens the voltage at the upper
 terminal is about 6 volts and at the starter terminal the same (was 6.58v when I last measured it)
I have tried 3 starter relays and they all perform the same way. I took the cover off 2 of them and bench tested them and they were ok and performed as they should.
Tried another starter motor and this one engaged each time the button was pressed but only for 1 second or so each time before disengaging, bench tested and was fine
I then tried another starter with new brushes and this one was exactly the same as the original with intermittent engagement and only for about 1 second
All earths have been cleaned and coated with de-oxit, including the starter motor mounts
Continuity from starter button to pin #6 on Ignition module - ok
In desperation I tried another computer but no difference
The headlight will go off when the starter is pushed and the starter engages but not when the relay just clicks
Dismantled and cleaned the starter button
The fuel pump works ok and pressurises the fuel line and cuts off 1.5 seconds after release of the start button - I have now pulled fuse #6
I thought the voltage from the battery may be an issue but the results were just the same when hooked up to the car
Once yesterday the starter did spin over for about 10 seconds until I released the button but this was a one off and I have not been able to replicate it
I am leaning towards faulty Starter relay but surely 3 of them cannot be broken


The rest of Bert's trouble shooting is for when the engine is cranking


Anyone got any further suggestions before I get a new starter relay and try it???

From what you say the relay is OK but it sure sounds like the starter is in dire need of attention.
Take the starter out then mark the case and both ends with a scribe so that when it goes back together it will work correctly.
Pull the 2 long screws out and if you can get the ends off be prepared for some badly corroded parts. If you are lucky it might just need brushes but more likely the armature is cactus due to rust etc.

Rick,
I have tried 3 starters, one of which had been cleaned and a new set of brushes, it was my spare

bad earth cable ?

theres a lot of dropped volts happening there that should hold up to a fair bit higher than what your seeing

Yeah, that was my first thought but I am unsure how to really check. Right at the start I thought there must be an earth to the start relay but couldn't find one on the interactive diagram, so I checked for continuity with all the earth wires under the tank but no good there, so I just cleaned them all up. No brown wire at the relay so from then on my understanding is very limited. Bert says about earth to pin 86 but not sure how to go about this check as I think it must kick in when the starter button or some such is pressed. I find wiring diagrams really difficult. If you or someone else can walk me through the process I would be very grateful
Mike

Sounds like some wiring issues buried in there if you have [by passes relay and associated wiring]. It should turn over normally in which case its ok for now and you have other problems. If it doesn't then the brushes and internal corrosion/crap are your issues.

Packo wrote:Rick,
I have tried 3 starters, one of which had been cleaned and a new set of brushes, it was my spare

Well that rules out the starter. I would try going from the positive of the battery direct to the terminal on the starter.  That rules out the starter or ground connection. Also the ground for the starter is the body of the starter itself onto the intermediate housing so make sure the 2 6mm allen bolts are clean and tight (8ft/lb no more) and be sure the negative lead from the battery to the gearbox is clean and tight at the terminals. It also should be a good thick cable not the pissy little one that some K100s have, at least as thick as a pencil.
The 2 main terminals on the relay with the screw connections, if you short them together then the starter should work, if not then look further at the cables.

to rule out the earth cable put one lead of the multi meter on the earth side of the battery
the other side to the starter case ...you should be on 20 volts scale

now crank the starter ...if you get more than a few volts shown on the meter then you have found the issue

good luck

Packo wrote:Yeah, that was my first thought but I am unsure how to really check. Right at the start I thought there must be an earth to the start relay but couldn't find one on the interactive diagram, so I checked for continuity with all the earth wires under the tank but no good there, so I just cleaned them all up. No brown wire at the relay so from then on my understanding is very limited. Bert says about earth to pin 86 but not sure how to go about this check as I think it must kick in when the starter button or some such is pressed. I find wiring diagrams really difficult. If you or someone else can walk me through the process I would be very grateful
Mike

Earthing to the starter relay is provided by the ICU through the Brown/Red wire (Pin 85). There is no measurable continuity to frame ground on this wire in a normal state with the engine running. The ICU controls the ground lead to the starter relay so that it can cut off current to the relay when the engine fires. That is a safety feature the prevents the start motor from running if the operator pushes the start button while the engine is running.

How old is the battery?  12.33 volts is not a fully charged battery, in fact, that is what you would read on an almost dead battery.    Are you reading the voltage right on the battery terminals? 

It sounds like you have cleaned all the grounds, changed starters, and done a lot of others tests.  If the starter relay is being energized, there isn't much that can stop the starter from turning.  One thing that would be interesting would be what the voltage is at the point where the battery ground cable connects to the engine.  Check the voltage between the ground on the engine and the negativee terminal on the battery.  That voltage when the starter is energized should be 0.0v.  It's unlikely the negative cable is bad, but there is always the possibility. 

Unless the battery is brand new, I'm of the opinion that is your problem.  Last summer I had the same problem with my battery where it ran the lights okay, but would not turn the starter.  Replaced it and the problem was fixed.  Most places that sell batteries will gladly load test your battery to see if it is up to the job.

Thanks to all for the replies, I have worked my way through the suggestions and here are the results:

1a. Check the voltage between the ground on the engine and the negativee terminal on the battery.  That voltage when the starter is energized should be 0.0v.

1 b. to rule out the earth cable put one lead of the multi meter on the earth side of the battery
the other side to the starter case ...you should be on 20 volts scale

now crank the starter ...if you get more than a few volts shown on the meter then you have found the issue


Result : main earth ok 0.0 volts

2. I would try going from the positive of the battery direct to the terminal on the starter.

Result : Starter turns over slowly, just like a flat battery

3. The 2 main terminals on the relay with the screw connections, if you short them together then the starter should work, if not then look further at the cables.

Result : Same as above, starter struggles to turn over

The battery was charged overnight and at the start had 13.44 volts this morning when these test were carried out and after it was
12.44v

I did some further voltage checks as well as follows:

Starter relay Ignition OFF Lower terminal 12.7 v, Higher terminal 0.0v, Pin 85 0.6v, pin 86 0.0v
Starter relay Ignition ON  Lower terminal 12.7 v, Higher terminal 0.0v, Pin 85 0.6v, pin 86 0.6v

When the start button is pressed here are the results
Lower terminal 6.5 v, Higher terminal 5.7v, Pin 85 5.4v, pin 86 5.9v

The battery was new in April 2017 and has been used in another bike since then with no issues whatsoever but with that massive voltage drop when under load I am off to get it checked. Think I will be coming home with a new one
Thanks for your help and I will post up how I get on

Put the meter across the battery and press the start button if the voltage drops below 10.5 volts then chuck the battery.

Picked up a new battery and starter spun like a top
Replaced the injectors with ones back from the cleaners and I had a runner
Thanks for the help

good work packo

ride well mate

Now get out there and enjoy your ride while those of us in the Northern Hemisphere settle in for the winter.

Wish I could but now have other issues!!!

In preparation for getting the bike going I had drained the coolant and refilled it with water and a product for cooling system flushing.I ran the bike until the fan came on then switched it off in order to do the system flush.
However, I noticed this milk coffee coloured "oil" in the sight glass.

I have now drained the sump and removed the filter. Will have to wait til after Xmas to get the pump off and hope like hell it is only the water/oil pump and nothing more sinister. Should I drop the sump and engine covers in order to get rid of more of the contaminated stuff or could I use some detergent type oil for a while once this issue is sorted or will it burn off.
I know the procedure for the pump is well documented here so I will study up is there anything else I should be aware of ???