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1Back to top Go down   1985 K100 RS won't start Empty 1985 K100 RS won't start Mon Feb 26, 2018 1:34 am

FrederikHolm

FrederikHolm
active member
active member
Hello! 

As i mentioned in my intro post, my name is Frederik and I am currently restoring my dads 1985 K100 RS. 
After reassembling the bike, I had it up and running but had to turn i off again, since there was still a few bits I needed to fit.

A few days later I wanted to start it up again, and it wouldn't start. 
Decided to pull the plugs to check for sparks. The four plugs all spark, all though i would have expected a more power full spark. Drained the gas tank, and put in some fresh fuel, still not starting. Pulled the plugs again, and noticed that they are soaked in gas. 

Decided to remove the injector bar to check if any of the injectors where stuck in the open position, but the where not. I did notice that they spray in a very thin pattern. Don't know if they are supposed to do that, but I found this video on YouTube and it is prettys simmilar: https://www.youtube.com/watch?v=n06q8fjFR9k

I then found Bertrand Vogels guide on troubleshooting the K100; http://hrsbstaff.ednet.ns.ca/bvogel/K100/download/bike-wont-start1.htm (Great guide by the way, thanks a lot)
Since I was pretty sure the fuel was not the problem, I decided to check the ignition coils. 
As the guide descibes, there should be around 12.6 kΩ between the secondary coils and 2.6 Ω between the primary coils. 
Heres my measurements:

ZYL. 1 & 4:      Primary = 0Ω     Secondary = 0Ω

ZYL. 2 & 3:      Primary = 0Ω     Secondary = 9.57 kΩ


It would appear that there is a failure in the ignition coil serving the nr. 1 and nr. 4 cylinder. But how can a spark occur, at the sparkplug of both cylinder 1 & 4, if the coil is bad? As i mentioned, I have sparks at all four cylinders. 

Appreciate the help! 

Kind regards, Frederik.

    

2Back to top Go down   1985 K100 RS won't start Empty Re: 1985 K100 RS won't start Mon Feb 26, 2018 2:21 am

MartinW

MartinW
Life time member
Life time member
More than likely faulty temperature sensor or connection. Clean the connection first with DeoxIT and if that doesn't work test the sensor.
Regards Martin.


__________________________________________________
1992 K75s
    

3Back to top Go down   1985 K100 RS won't start Empty Re: 1985 K100 RS won't start Mon Feb 26, 2018 3:49 am

FrederikHolm

FrederikHolm
active member
active member
Will try that. Appreciate the feedback.

    

4Back to top Go down   1985 K100 RS won't start Empty Re: 1985 K100 RS won't start Mon Feb 26, 2018 4:46 am

charlie99

charlie99
VIP
VIP
if you have spark ...likely to be the under seat computer plug has worked loose , or the fuel pump connector  has worked loose (under right hand sidecover ...and a very common issue )

I think your procedure on measurements on the ignition coils is flawed - likely wrong settings on the multimeter is all I'm saying

walk around again and notice things that are unplugged ..even partially

don't forget the fuses ...wiggle them a bit  and see what happens

good luck


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

5Back to top Go down   1985 K100 RS won't start Empty Re: 1985 K100 RS won't start Mon Feb 26, 2018 6:24 am

FrederikHolm

FrederikHolm
active member
active member
Thanks, will have a look.

    

6Back to top Go down   1985 K100 RS won't start Empty Re: 1985 K100 RS won't start Thu Mar 01, 2018 3:44 am

KiwiK100

KiwiK100
Gold member
Gold member
Spark plugs with throw what a appears to be a solid spark when earthed against the engine for example, but will struggle under load in a combustion chamber. Just because it shows a spark to the naked eye does not mean all is well with the electrical system. 


__________________________________________________
Current rides:
2020 R1250RS. Metallic black with all the fruit
1983 K100C. Red. Krauzer fairing.
1984 K100RS. Madison silver.
2002 K1200RS. Owned from new. Pacific Blue, Ohlins, Speiglers, Fiamms, HID. 186,000km SOLD Crying or Very sad
1991 K1. Schwartz metallic black, 18 month frame off restoration. 74,000km SOLD Crying or Very sad
1987 K100RS Style. Black, Ohlins, Race Tech springs, Braided lines. Fully restored. 53,000 miles. SOLD Crying or Very sad
The family history:
1951 AJS 500 single - my Dads ride
1953 Triumph Terrier - my Mum's ride
1916 Triumph Type H, Battle of the Somme, France WW1 - my Grandads ride
    

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