More r80 woes

[SeanW]

Sorted the bean can, points and ignition timing on my 1979 r80/7 (see pre Xmas thread), bike running very well for last 2 weeks. Went to start it at work for ride home (all fine on way in) and I have a total electric failure. It was momentarily alive until I hit the starter when everything went suddenly completely dead.

The two 8a fuses in the headlamp shell look ok. So what’s likely to be buggered? Starter relay?

 

[Blackplate]

I’d look at the starter relay mount under the tank. They’re vulnerable to weather, time & drips of brake fluid from old under tank master cylinders on these old /7s. I’ve seen the positive lead that feeds into it get very corroded on a number of occasions & even drop out of the relay mount block.

 

[ChasF]

Battery, battery terminals, earth connection on the geabox.

 

[kettle738]

I had similar symptoms on an R100CS...... (after changing the starter motor ) I discovered by accident that the battery negative lead had corroded internally about an inch from the top to the point that there was just enough left to run all the electrics until the moment the starter button was pressed when all the electrics blacked out....although the fuses remained intact.

I only discovered it when I was moving the cable to refit it and the top terminal came off in my hand along with an inch of very corroded cable......it looked perfect from the outside........I replaced the cable and all was well.

Mick.

 

[SeanW]

Thanks gents.

I had a quick fiddle with it in car park this morning and discovered that turning the bars to just the right position brings the power back though in a very hesitant much clicking of relays kind of way.

Going to van it home for proper investigation tonight.

 

[Big Jets]

My gs done the same bad connections in the block connectors under the tank

 

[Blackplate]

Any news in progress?