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I’m sorting out some wiring issues on my 450 Desmo and wondering where the best place to attach an earth to the engine is. I cobbled one together on one of the crankcase pinch bolts but is that where it’s supposed to be? I can’t see anywhere else obvious.

Ian

Not much good to you now you have your engine built but I always make a small aluminium angle piece bored horizontally to take a head bold and bored vertically to take an earth connection, its a very secure and electrically sound position and cannot really be seen, The other good spot is an earth tab secured under the lower back engine/frame bolt....put a bit of black heat shrink on the wire and you won't see it.
Cheers George

Thanks George,

Both of your solutions seem sensible but what I can't understand is where the original location is (or was there no earth strap and they simply relied on engine to frame connection)?

Ian

No earth cable as standard on any Ducati single I've seen.
There's no big current demand like for an electric starter.

Jordan is absolutely correct, there was no earth to the engine originally.......but with so many bikes during restoration having their frames plastic coated the electrical bond between engine and frame can be compromised.
Cheers,
George

OK, thanks for the responses. I was guessing there was no earth strap originally (because of no starter load to worry about) but good to have it confirmed.

Ian

Jordan wrote:No earth cable as standard on any Ducati single I've seen.
There's no big current demand like for an electric starter.

Even elec starter models like 900S2 have no engine-earth cables! Ducati relied engine-frame conduction.

Hmm, that would be why I couldn't find one on my Darmah when I rebuilt it (and why I created one anyway).