I'm building some engine mounts and I'd like to tack weld the supports to the mount plate which I've bolted to the engine and then unbolt the plate and weld up the support on the bench.

Is tack welding the metal while bolted to my engine going to cause any damage?

The engine is a 2003 FI yamaha R1 with the loom removed but all the injectors and stuff still attached.

Thanks,

Mark

it shouldn't be a problem if the bracket plate is PROPERLY grounded and with the loom removed. The injectors are insulted from the engine aren't they so they should be unaffected? if its only tacking there should be ne localised heatting worries

I would say no probs BUT i am no expert and its just my 2 pence worth.

I agree with Liam.

Only other issue is keep the ECU (if you have one) away from the weld area and the welder itself.

Large electromagnetic fields will knacker the ECU PDQ

Cheers guys

Mark

Will be ok. Like said above keep the ecu away from it and watch the splatter near your injector terminals.

Your most venerable part is the alternator - disconnect it before welding or use a protector unit across the battery