Shorting front cover / I'm embarassed

[JR50]

'69 R50US, stock 6v, new emerald island coil, new points, original advance unit

Last summer I was trying solve an overly retarded timing issue, running the bike with the front cover off, adjusting the points gap, check with timing light (external 12v battery), adjust, drop feeler gauge, curse, repeat.

Got it as best I could i.e "close enough" sweating and swearing on a 90F day. Put the front cover back on, kick, no start, no spark.

Immediate dread- did I or did I not disconnect the battery before reinstalling the front cover? Walk away despondent.

Now that the embarrassment has faded, any advice on where to start to look for evidence of a short- fried diode board, etc?

Sincerely,

Captain Ambition Outweighs Talent

[schrader7032]

First I'd take the cover off and see if it will start.

Concern over the front cover removal is a real issue on the /5-on bikes as I believe there are circuits that are live on those bikes. It's been said to do the same thing on a /2 but I'm not so convinced that the issue is as concerning on them. I'd love to hear more, but the only power on a non-running bike is from the battery which only powers the lights. I didn't think anything was live under the cover.

Thinking about it some more, since the generator is underneath the cover and the generator is connected to the battery in some fashion, there is the possibility there are some live wires underneath the cover.

[Seek]

First, your R50 has a magneto ignition. It is totally independent of the battery. I guess your high tension leads are stripped a bit too long, with the copper touching or almost touching the cover where they are connected to the coil. Or it is some silly little thing like you forgot to press down the ignition lead…..

Second, yes you should disconnect the battery when you remove or reinstall the cover. You can easilly touch the lead to the battery down right side. Sparks will fly. It doesn’t hurt much, no fuse in these bikes. But I don’t think it is healthy for the battery.

[Slash2]

Perhaps you only inadvertently reversed the polarity of the regulator.

[niall4473]

It is possible to nip the magneto earthing wire with the front case, which will prevent starting.

[Luddite]

^^^
That's exactly what it was when it happened to me. And somehow it had only nipped half of the wire, so the crushed part wasn't so evident, and it took a close inspection to see the bared wires.

Shorting with the front cover is something I find really easy! Having done it a few times (laziness and clumsiness are not a good combination) I now always disconnect the battery when working up the front there.