I'm looking to relocate my EFI (I think that's what it's called--the computer that runs everyting and lives under the seat/tool tray) as part of a cafe racer build.  To do that, I need a longer wire.  I could easily cut the existing wiring, solder in some longer leads (probably adding 16 inches or so), and move it where I want to (which would actually be under the tail section).  I would use shrink tubing to insulate everyting after soldering.

My question:  is this a bad idea?  I'm more than willing to be talked out of it if doing this is unwise or would create probems.  As you might gather from this question, I am very weak on electronics, so I could really use the sage wisdom of others on the board.

So, not recieving any responses, I've been thinking over the possible downsides of this.  I'm thinking the worst case scenario is that it wouldn't work and I'd have to buy a new wiring harness.  The list price at MAX BMW is about $200.  That would be unfortuante, but not the end of the world.  But I don't know about the actual availability of the part (new or used).  Anybody have knowledge about that?

As long as the joints are soldered properly then there shouldn't be any problems. Butt the stripped wires into each other (push your fingers on each hand together and you'll get the idea) before applying solder as this minimises the increase in diameter. Somewhere around 5mm of stripped wire will do fine for the joint. Stagger all the joints - you really don't want a huge increase in the overall diameter of the wiring loom. I'm being lazy and can't be bothered to check a wiring diagram but IIRC there's only eight or nine wires to do anyway. Use a GOOD quality pre-fluxed solder and a soldering iron of approx 30watts. Any less and you won't get enough heat into the joint; any more and you stand a change of burning the existing PVC covering.

Have you got four hands?

Thanks Dai.  Appreciate the tips on soldering also.  On other wire I've soldered (Acewell speedo/tacho, turn signals) the adjoining wire insulation is just staring to get tacky when I get it all soldered up and nicley joined.  So I think I'm hitting the sweet spot on heat.  I've been using some spring clips attached to a small board to hold things together while soldering. But a few extra hands would help!  Thanks again for the response!

Just as Dai said except that you need 6 hands, you need to keep the heat shrink out of the way as well

KJustin wrote:Thanks Dai.  Appreciate the tips on soldering also.  On other wire I've soldered (Acewell speedo/tacho, turn signals) the adjoining wire insulation is just staring to get tacky when I get it all soldered up and nicley joined.  So I think I'm hitting the sweet spot on heat.  I've been using some spring clips attached to a small board to hold things together while soldering. But a few extra hands would help!  Thanks again for the response!

You are twisting them to each other before joining them inline?