No spark

[jackstraw]

I’ve recently tilted the engine to work on the carbs. I’ve rebuilt it today and when I’ve gone to start the engine turns over well but on inspection there is no spark at any of the spark plugs
Everything else seems to be working well, with the exception of the indicators which are flashing faster than usual. Otherwise starter motor is turning over nicely, and lights etc all working
I’ve checked the four electrical connectors under the right side panel and all seem connected and clean

What might I have done wrong, what should I check next?

Thanks in advance

[jnnngs]

Hi,

Almost certainly an electrical issue. Need to check you have power getting to Igniters /coils. Start with the basics:
- check kill switch, needs to be "on", and make sure it is working - they can / do fail.
- will only start if in neutral (or if clutch pulled in). Check neutral switch is working OK.
- there is an earth wire from the wiring harness next to the coils, make sure connected to frame where coils are mounted.
- check the fuses just in front of the handlebars. Take fuses out, clean up connections - fuse may be OK, but high resistance connections is common.
- check all connections on right side, mounted on battery box and air box. Clean them all out - as above high resistance connections are common after 40 years!

If that doesn't show anything up, get a multimeter and make sure power is getting to coils / igniters - use the wiring diagram in the service manual.

[Larry Zimmer]

If you don't ind something obvious, be certain to check 'inside' connectors. This applies particularly to 'bullet' connectors that are inside a protective sleeve of some type. Things can appear to be connected. BUT, they are not. (Voice of experience, here)

[jackstraw]

Thank you both for your replies, do you have any hints/tips for cleaning up the contacts in the block connectors without pulling the wire out.

I'm worried the wire/connector coming out of the block will not remain intact if I pull hard (even after lifting the securing tab)

[jnnngs]

Thank you both for your replies, do you have any hints/tips for cleaning up the contacts in the block connectors without pulling the wire out.

I'm worried the wire/connector coming out of the block will not remain intact if I pull hard (even after lifting the securing tab)

use electrical contact cleaner - WD-40 has a spray can version.

https://www.screwfix.com/p/wd-40-contac ... lsrc=aw.ds

[daves79x]

Check your static timing and make sure your advancer shaft is turning with the engine.

Dave

[jackstraw]

Good news
The black wire within the kill switch had broken away from the solder and so was not making any connection. A local auto electrics specialists repaired it for me, I've refitted the kill switch and the bike now starts. Replaced the indicator (turn signal) relay and the indicators now work properly too

Thanks for all advice
Jack

[steve murdoch icoa #5322]

Congrats on getting it sorted.