Intermittent spark

From an older 550 service manual.
diode bank should be the same as the wire colors are the same.

His service manual should have the procedure for checking the diodes

So Svanslos,

You will have to locate the diode pack. 
My guess it will be close to the igniter

6 wire connector

3 brown/white wires 
1 light green wire
1 yellow/green wire
1 brown wire

disconnect the connector to the diode pack

set your meter to resistance

on the diode pack
you will place your red probe on the first brown/white terminal and black probe on the yellow/green terminal
what is the resistance?
reverse your probes--black probe on that brown/white terminal and red probe on the yellow/green teminial
what is your resistance?

next
move your probes to the next terminals over.

red probe on the brown/white terminal in the middle slot 
black probe on the brown terminal
what is your resistance?

reverse your probes
red probe on brown
black probe on brown/white
what is your resistance?


move your probes over to the last slot
red probe on brown/white
black probe on light green
what is your resistance?

reverse the probes
red probe on light green  terminal
black probe on brown/white
what is your resistance?

so your two readings with each slot should be different when the probes are reversed.
the two readings should never be the same.
there should be at least a difference of 10x between the two readings.

one direction maybe 10 ohms
reversed should be at least 100 ohms

if the readings are the same, you have a bad diode inside.
there are 3 diodes inside that diode pack.

   



 

 

Thanks for fantastic advice, just left the workshop to celebrate midsummer, will be back Monday with my spirit high and test the diodepack! Update will surely follow

H using this system on 74 900 and a 81 650, please search retrofit ignitions, the diodes are a fancy way of tying all the starter interlocks together to provide 12- to  the igniter, info on old post was obtained from classik forum, proof the diodes? ground out the black/yellow and the Br?/w, (other diagram show it as a black/ white, in the diode plug, the feed 12- to ignitor, see if it runs, wold put up a link, don’t know on ipad thx

Thanks Jewels I think we have established the ground is missing on the black/whitw

Good morning! I get a reading on the diodes with the multimeter set to the "diode" option. One way on all three diodes it read about 620, reverse the probes and it read "I". Multimeter set to resistance on the 200k range i get a reading of about 160 on all three diodes and "I" if i reverse the probes. This is when the bike has not been running, will try again when i have hadr the chance to run it.

Once you have had chance to run it, if/when the fault occurs try fitting the bridging wire I mentioned between the black/yellow and brown/white at the igniter

Fault occured, The diodepack reads the same, and no difference with the bridging wire  between black/yellow and white/brown

SvansLös wrote:

Fault occured, The diodepack reads the same, and no difference with the bridging wire  between black/yellow and white/brown do you mean still no spark ?

OK so bridging the brown/white with black/yellow by-passes the side stand switch, clutch swich and neutral light switch
Battery voltage on the green and black at the igniter confirms coil circuit ok (feed to coils, coils and wires to igniter from coils)

Did you check for battery voltage at the yellow/red on the igniter ? if yes that only leaves the pick-up coils or the igniter - have you carried out the checks in the manual for the pick up coils at the igniter plug ? (this will check the wiring as well as the pick-ups)

Take a can of air, turn it upside down and spray the igniter to freeze it when the bike dies. You may have an igniter that fails when it gets hot.
Don't spray it when the bike is running.. it's slightly flammable as a vapor.

I have measured resistance in the 4-pin connector for the pickupcoils, with multimeter set to the 2k range it reads .450 on both with or without spark.  There is a test table for resistance on the male ignition coil connector aswell, which connector would that be? 

SvansLös wrote:

I have measured resistance in the 4-pin connector for the pickupcoils, with multimeter set to the 2k range it reads .450 on both with or without spark.  There is a test table for resistance on the male ignition coil connector aswell, which connector would that be? 

Have you also measured the resistance for the pick up coils at the 10 pin plug for the igniter (with the igniter disconnected) ? this checks the wiring between the 4 pin and 10 pin plugs. Can you post the test able you are referring to for the ign coil connector (I don't have sight of a manual for your bike)