Topic: What gauge wire should I be using to rewire/upgrade electrical? CB750K4

[Avalachegantch]

Hey everyone, looking for some opinions and advice on what everyone on here may have used when upgrading electronics.

I am currently fixing up a 1974 CB750K4 and the owner before me made some electrical modifications that were straight garbage. I planned on completely revamping the electrical anyway so I guess it is just going to come a little sooner than later.
I have already purchased all the parts to upgrade:
-LED headlight and tail light with blinkers integrated
-small form Li-ion antigravity battery
-New Regulator
-New Dyna ignition and coils
-New solenoid
-Blackbox v3 kit with push buttons

My question is, when I am wiring this up considering the fact that I am using li-ion batteries now, do I need to use any specific gauge copper stranded wire outside of what is being used on the original wiring harness? I see there seems to be multiple answers on this forum and on google. I have read for components usually 18-16 gauge, and for battery terminals anywhere from 16-4 gauge. I was hoping some friends on here that have been down this path before could provide some insight here.

Also, I was wondering where you all buy your automotive wiring from? On amazon the color selection is kind of limited but I was hoping to separate every cable color based off its destination from the controller unit.

Thanks, 

[Emagbnim]

I can't give you a 100% guarantee about this but I asked an electrician friend of mine about this when I rewired mine.  He told me its ok to use a larger gauge(as in a larger wire the gauge numbers get smaller the thicker the wire) and that it shouldn't pull more power then it needs.  If you go too small they can overheat, burn through and maybe start a fire.  So generally thickness of wire depends on how much power needs to run through it and for how long power is running through it. It will always be safer to go a little thicker just don't go crazy.  Definitely don't use something as small as 16 for your battery though.  I think I used 6 gauge for my battery and its been ok so far.  Though I haven't run it for an extended period of time yet so take what I say with a grain of salt.   Also another thing to note is that terminal ends for really thick wire like 6 gauge are a bit different and may require solder or a special tool to crimp them down. 

Definitely get separate colored wire if you ever hope to be able to work on it afterwards or to have someone else work on it.  It would especially help if you stay as close as possible to the stock colors as that would make it much easier for someone familiar with the stock wiring to work on it.

I got mine off amazon but there is a lot of different vendors on there.  Best I could say is get a bunch of different types and try them out.  Most of them are pretty cheap and you don't really need much wire for a bike.  Maybe someone else has a favorite brand they can suggest.

Oh and also since you were asking specifically about a lithium battery.  You shouldn't need anything special wire wise for it as it should put out the same amount of power as a lead battery but what you do need is a regulator designed for lithium batteries which it seems like you got.  The reason you need that is lithium batteries can't take as many amps when charging as a lead battery can.  The charging system on the bike is made for a lead battery so it would overcharge and likely destroy a lithium one.  That regulator will be wired between your battery and the charging system so it will lower the amps going into it.  You would also need a charger designed for your specific battery.  I'm not sure if you have the same one as me but mine can't take more 4.3 amps.  It should say somewhere on the battery the max amps it can take and if not definitely in the little book that should come with it.


I hope this helps and good luck.

[Avalachegantch]

Hey man, I really appreciate all the insight here. I have a follow up question, what is the difference between tinned copper stranded wiring and copper stranded? For some reason I feel like copper stranded is better, and I will probably just Google it and circle back and this thread.

Also, with the crimper tool and connectors, a big part of why I didn’t buy the wiring yet was because a lot of the crimping tools online were 10 gauge to 18 gauge. So I’ll probably have to look for a specialized one.

[MauiK3]

You can get sets of vintage style bullet connectors on line that are the correct size.

[MauiK3]

http://www.vintageconnections.com/

[Emagbnim]

I'm not really an expert in this but from what I read the tinned copper strand is better if you expect the wiring to be exposed to a lot of moisture.  Which wouldn't be detrimental but also probably isn't necessary in most cases.  I would assume the tinned wire is more expensive?  So it would be up to you.  If you wanna spend a little extra for a little extra protection.  If you lived in an area that sees a lot of rain and you don't have a place you can store the bike inside it could be worth it other wise probably not.

Another good thing to get is a heat gun and some heat shrink wraps.  You put them on where the connectors meet the wire.  Then hit them with the heat gun and they shrink down to grab both and make a seal between them.  They help to protect the wire against moisture getting in at the points where you have to strip the wire to connect them to connectors.  Some connectors will come with the shrink wrap already on them and you just have to heat them up.

There is some good stuff in that site mauik3 posted.

[Avalachegantch]

Thanks again,

I pretty much read the exact same thing about the copper back timber copper. I live in Michigan so we have good deal of humidity, it’s going to be unlikely that I’m riding in the rain but I’ll probably do tinned copper anyway.

Also, thanks for the site, I’ll check it out!

[TwoTired]

Using the same gauge wire as what Honda installed is the safest bet.

But, note it has a high strand count as robotic wire has.  The thicker each strand is, the more susceptible to bending and vibration bending fatigue breakage.

Try to find a wire chart that includes a temperature specification, and note that wire in a bundle won't run as cool as those hanging in free air.

Plated wire is used to preserve the copper from corrosion (which would making it thinner or narrower in cross section over time).  The plating is sacrificial.  As in, it will corrode and oxidize prior to the plated core.  The plating is not in and of itself much aid to carrying electrical  current.  It just prolongs the life of the core wire.

The lithium battery has no effect on choice of wire different from stock.  If battery is rated for ~210 CCA, it will both deliver and receive such current without harmful effects.  But, that is controlled by the voltage potential available at the terminals.  You can't push current into it without a higher voltage potential than it has statically.  And that is why you need a voltage limiter for the battery, (that most call a regulator).  It is there to keep from putting more energy into the battery than it can safely store.

One caution.  Most of the lithium types have a spec in the warranty about over depletion voiding it.  That means if you leave the key on and or lighting, the battery can be damaged by a deep discharge.  Lead types can be damaged by this too, but it is much more forgiving of such abuse.  Lithiums are less reliable to recover from this.  Most other electronic devices that use lithium type batteries monitor for too low voltage and disconnect it to save the battery from harm.  I know of no such device available for the SOHC4.

Cheers,