hello everyone. i'm having a bitch of a time getting my cb to run consistently. i won't bore y'all with the backstory but at the moment my prime suspect is the neutral switch. it appears to be playing up when the engine is hot and cutting off the spark.

on my cb the neutral switch shows up as two wires which emerge from the gearbox casing; one from the lower left hand side near the side stand, and the other from the top of the casing towards the right. these two wires plug into a 2p connector which feeds into the wiring loom. when the switch is functioning correctly (neutral light on and engine sparking) the resistance between the two wires tests at about 70 ohms.

i've tried dummying the switch by shorting out the 2p connector with a 65 ohm resistor, but it's not fooling the cdi. the neutral light stays off and the engine won't start (even with the clutch in).

my question is this: how can i set up a faked neutral switch?


for reference here are a few scans from the manuals i've found the net:

the entire circuit (workshop manual for the NC31 is half russian)



i think the wire labelled 3 leads to the switch (from a japanese parts fiche)



thanks!

Strange goings on! Even in gear you should be able to start the bike with the clutch pulled in.....

strange goings on indeed. so i had a look and found a more detailed diagram of the starter circuit:

CB1 on left (for comparison) and NC31 on the right
image is too large

and the full loom for what i think is an NC31:
this image too

i guess i'll be heading out tomorrow to pick up some diodes