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1Back to top Go down    1985 K100 RS won't start on Mon 26 Feb - 5:34

FrederikHolm

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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 kΩbetween the secondary coils and 2.6Ωbetween 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    Re: 1985 K100 RS won't start on Mon 26 Feb - 6:21

MartinW

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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.


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K75s Hybrid
    

3Back to top Go down    Re: 1985 K100 RS won't start on Mon 26 Feb - 7:49

FrederikHolm

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Will try that. Appreciate the feedback.

    

4Back to top Go down    Re: 1985 K100 RS won't start on Mon 26 Feb - 8:46

charlie99

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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


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

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
    

5Back to top Go down    Re: 1985 K100 RS won't start on Mon 26 Feb - 10:24

FrederikHolm

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Thanks, will have a look.

    

6Back to top Go down    Re: 1985 K100 RS won't start on Thu 1 Mar - 7:44

KiwiK100

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Spark plugs with throw what aappears 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.


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Current rides:
2002 K1200RS. Owned from new. Pacific Blue, Ohlins, Speiglers, Fiamms, HID. 167,000km
1991 K1. Schwartz metallic black, 18 month frame off restoration. 74,000km
1987 K100RS Style. Black, Ohlins, Race Tech springs, Braided lines. Fully restored. 53,000 miles.
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 Grand dads ride
    

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