CB750 Barn find project - First Timer

[Trigger]

Change any bullet and spades. If you see any green on the wires, then cut back. Corrosion is not your friend on these old girls 

I found a little corrosion on a regulator the other week that cooked a brand new battery 

[Underdog1]

Change any bullet and spades. If you see any green on the wires, then cut back. Corrosion is not your friend on these old girls 

I found a little corrosion on a regulator the other week that cooked a brand new battery 

Ok might as well go all in then. I had to stick a punch of bullet connectors on a universal speedo gauge, I thought Honda used 3.5mm connectors so bought some on eBay and they seem a little small, the female connectors are fine but the males struggle to stay in. I’m guessing I should be using 3.9mm?

Any recommended sources or are they all much of a muchness?

[Underdog1]

Nope, the ground to the horn is PN 38105 323 000  Or 38120 392 620

Mate just had another look at the wiring diagram and it seems the horn button does ground on the bars

http://manuals.sohc4.net/cb750k/technical_reference/WD750K6.pdf

Surely this would require a good ground to the bars and a good ground from the bars to the upper fork clamps. Might have to sand a little bit of powder coat off.

Some positive news today, my V5 finally arrived after many headaches. DVLA were particularly useless.

I’m side mounding the plate so going to have it in 3 lines, what’s the correct format for this? I’ve seen:

  X
XXX
XXX

 XX
 XX
XXX

And

XXX
XXX
  X

[Trigger]

All need a good ground or you will have trouble 

[Nurse Julie]

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Can be white or silver on black if pre 1977 (rolling)
But, you can have it on 3 lines if registered prior to 2001.

[Bryanj]

Part of the grounding system is the headlamp shell bolts that screw into fixed nuts with ground wires that connect to loom

[Underdog1]

absolutely sick of the electrics on this bike. Unwrapped the old harness and replaced any bits of wire that looked dodgy, replaced a lot of connections and cleaned the rest up. Re-wrapped it and fitted to the bike. All I've got is a bloody oil pressure light still!

Feel like sacking it for a few weeks as I've totally stopped enjoying working on it.

[Trigger]

The fun of custom builds, that is why i hate them.

[Underdog1]

The fun of custom builds, that is why i hate them.

I’ve really enjoyed the physical modifying of the bike, the cutting and welding etc but I’m finding it hard to stay motivated with the electrics as it’s something that really doesn’t float my boat.

I’m considering buying a new K6 harness. I bought an earlier harness but it’s proving a pain to get it to work without a starter safety unit.

Although it’s a custom build the electrics are basically unchanged, the idiot lights are integrated into the speedo but the standard wiring should work. The only real difference is the left hand switchgear has a hi low switch. The old harness had a jumper cable (presumably as standard) to allow for the lack of on off headlight switch on the K6.. I can’t remember where it went though!

[Bryanj]

I seem to remember brown/red went from rh switch to fusebox and returned to headlamp as a brown/blue

[Underdog1]

I seem to remember brown/red went from rh switch to fusebox and returned to headlamp as a brown/blue

When I unwrapped the original harness some of the colours actually change inside the wrap, i think it was black/red coming from the bucket and changing mid harness into brown red to go into the fuse box. Strange

There’s a bloke on eBay selling k6 harnesses from Germany (but says made in Japan) for £95, DS does them the same sort of price. Anyone got any experience with either of these?

[Bryanj]

If you are building a special might as well make up your own loom mate

[Underdog1]

If you are building a special might as well make up your own loom mate

It’s not really a special in terms of electrics, the only addition is a repro right hand switch that gives me headlight on/off (which it didn’t originally have).

I think making a harness myself is beyond my skill set and something I’m not motivated enough to learn how to do so I’d have to farm it out to someone else which would no doubt cost many times what a repro harness costs

[Bryanj]

Where in the south west are you? anywhere ne Gloucester

[Underdog1]

Where in the south west are you? anywhere ne Gloucester

I’m near taunton, not a million miles away