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1Back to top Go down   EFI wiring question Empty EFI wiring question on Thu Nov 20, 2014 3:10 pm

KJustin

KJustin
Silver member
Silver member
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.


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1985 K100 Cafe Racer (formerly an RT), VIN 0051736
    

2Back to top Go down   EFI wiring question Empty Re: EFI wiring question on Fri Nov 21, 2014 9:50 pm

KJustin

KJustin
Silver member
Silver member
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?


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1985 K100 Cafe Racer (formerly an RT), VIN 0051736
    

3Back to top Go down   EFI wiring question Empty Re: EFI wiring question on Fri Nov 21, 2014 10:21 pm

Dai

Dai
Life time member
Life time member
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? Very Happy


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'83 K100 upgraded to K100RS spec, '87 K100RT
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California
    

4Back to top Go down   EFI wiring question Empty Re: EFI wiring question on Fri Nov 21, 2014 10:37 pm

KJustin

KJustin
Silver member
Silver member
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!


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1985 K100 Cafe Racer (formerly an RT), VIN 0051736
    

5Back to top Go down   EFI wiring question Empty Re: EFI wiring question on Mon Nov 24, 2014 12:14 am

RicK G

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


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"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1998 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki
    

6Back to top Go down   EFI wiring question Empty Re: EFI wiring question on Mon Nov 24, 2014 1:58 am

Mossy1200

Mossy1200
Platinum member
Platinum member
@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?

    

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