I'm chopping and re-mounting a HD crash bar and wonder, can I spot weld while it's in place? Would I disconnect ecu; pull fuses, whatever??? Thanks in advance...

 

I wouldn't take the chance. That's a lotta amperage happening there. Might fry your electrics.

Although back in the day, I had stuff welded while still on the bike, especially my GoldWing frame which cracked for no reason other than it was rice crap. And, my V65 Magna frame, and my 69 shovel cases. DID pull then engine when the chain let go on my CB750 & cracked the case. And my Norton kickstand tab, and my Triumph seat rails. Never hurt anything, but it's such a simple matter to remove the crash bars that I wouldn't chance it.

 

ground close to your work area *where yor welding* and if your really worried get a welding "anti-zap surge protector" they are made by severa lcompanies under many names but they clip to your battery and suck up majority of your errant voltage.

 

I have welded frames many times but do disconnect battery grounds and unplug any electronic control modules as a precaution.

 

A BIG pulse of RF comes off an arc. I wouldn't want my ecm or any radio system in the same room with it.

 

Loctite instead

 

Make sure you wear a tinfoil hat while welding.

 

On a travel log I read about some cycle travelers, they welded on an injected bike in the middle of nowhere and the bike didn't start resulting in a wait for new parts. I would make what we called a target when I was in the navy. Weld up a little jig with the same bolting points to do the tack and test fit.

 

I can't imagine why you want to weld it...??? So it breaks off instead of bends when you hit something?

 

And be sure to put your smart phone under your tinfoil hat first.