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After all the talk about main battery wires recently, I'm thinking that part of the problem I'm having with the LED lights on my Cafe Racer is the ground. I've bought some #4 welding wire and terminals and am going to make a wire to go from the left starter to engine bolt directly to the negative post of the battery. This wire is a tad shorter than the original ground wire.

My question is, is there any value in leaving the original wire on there? I'd like to hear that it isn't helping because it would be nice to be able to take that one off. I'll leave the vent bolt in place, and use a washer to take up the thickness of the original terminal in case the distance is critical for that vent bolt. To restate, should I leave the original ground wire, or can I ditch it?

Chuey

I don't see why you would need the original ground to the gearbox if you are going straight to the starter. Good idea

It is still wise to add a 10 gauge ground wire from the engine (preferabley the new battery ground) to the coil mount where the wireing harness grounds.

Rob Frankham's idea: http://www.robfrankham.co.uk/bike/earthing_article.htm

One caveat to my reply. One of the reasons that the battery ground goes to the trans vent bolt is that it is quick and easy to remove when you are pulling the front cover or in an electrical emergancy. (Smokin event)

So make sure your battery is mounted is a way that the ground terminal is super easy to get to.

No reason why the plan shouldn't work. Garnet makes a valid point re: accessibility.

Chuey wrote:After all the talk about main battery wires recently, I'm thinking that part of the problem I'm having with the LED lights on my Cafe Racer is the ground. I've bought some #4 welding wire and terminals and am going to make a wire to go from the left starter to engine bolt directly to the negative post of the battery. This wire is a tad shorter than the original ground wire.

My question is, is there any value in leaving the original wire on there? I'd like to hear that it isn't helping because it would be nice to be able to take that one off. I'll leave the vent bolt in place, and use a washer to take up the thickness of the original terminal in case the distance is critical for that vent bolt. To restate, should I leave the original ground wire, or can I ditch it?

Chuey

Chuey, I'm confused. I don't know what you mean by the underlined part of your post. Certainly if you create a good ground connection you can ditch the old one. But where are you going to move the ground connection to again? I think you meant to say that you intend to go from the negative battery post to a spot on the left hand side of the transmission.

That's where I mount the cable. Since the 6mm bolts on the back of the transmission go into a counterbored hole, you will have to create a special hardware stackup. There's a 6mm inside diameter bushing that often comes with new batteries which will fit nicely into the counterbored hole. You will need a longer bolt and maybe washers on both sides of the battery ring terminal. I use a hex head bolt rather than a socket head bolt to make it easier to connect and disconnect the ground connection.

When I make that cable I make it longer than the stock ground cable to give me the ability to use whatever battery that pleases me in terms of size and the location of the positive and negative battery posts.

On the other hand, maybe you were indeed planning to mount the end of the negative battery cable somewhere in the starter cavity, presumably under some bolt or other in there. That would be satisfactory, but I don't see it as being any better terminating there than on the transmission in terms of improving your LED lights. I'm not even ready to say that it's better for starter power mounted there as opposed to a good mount on the transmission. True you do have a non conductive gasket between the back cover of the transmission and the transmission housing, but you would be mounting the cable to a 6mm bolt which does screw directly into the transmission housing.

I suppose there is also some question about how good the ground is between the front of the transmission and the engine housing. But since we're talking about a cafe racer that you're building, the connection will have been cleaned and brightened already in the building proccess. It's not like you are depending on a 30 year old interface that hasn't been touched in that many years.

You've already been warned to make the ground connection easy to undo, so I'm not going to repeat the advice---ooops!

In any event I see it as rather arbitrary as to where you choose to connect the negative cable from the battery. There is, of course, a good reason for not connecting the battery cable at the stock speedometer cable takeoff point. So I say do whichever pleases you the most.


Ken

Chuey, I recently shifted my earth to a different bolt on the transmission because that venting bolt was starting to strip - I fitted a longer bolt with a couple of washers. I then added another 20 Amp cable from that bolt up to the earthing point near the coils, plus another 20 Amp to one of the metal posts that support the diode board (similar to the arrangement in Rob Frankham's article - thanks Rob). The results I've experienced since are similar to those noted by Rob - greatly improved charging and therefore starting, etc. Highly recommended.

What is the problem you are having with the LED lights?

Thanks all.

It is easy to see how one word (to) accidentally added to a sentence changes the meaning. Sorry for that. I plan to use the left bolt that secures the starter to the engine block.

There is so much stuff in the way that I can't hook up to the transmission bolts. The top two actually attach to a crossbar that attaches to CC products type frame stiffener tubes.

The access to the top of the battery is actually better than the access to the transmission bolt. That is where I disconnect the battery from the system.

I'm thinking I'll add that other wire to the wire harness ground point and then one to the diode board mounting screw.

Chuey

Edit: I just remembered, I don't have a diode board on that bike. oops!

Chuey wrote:It is easy to see how one word (to) accidentally added to a sentence changes the meaning.

Chuey

That, is so untrue - NOT!

Okay, I see what you mean.

Chuey wrote:
Edit: I just remembered, I don't have a diode board on that bike. oops!

Even more cryptic. I like a good mystry.

Garnet wrote:

Chuey wrote:
Edit: I just remembered, I don't have a diode board on that bike. oops!

Even more cryptic. I like a good mystry.

There is a dealie that takes the place of the diode board and the voltage regulator. It comes with some high output charging systems but works with otherwise stock setups as well. That's what I have. Mine is mounted under the seat on a pan I made just for electrical stuff. I'm thinking of moving it to the front of the bike as it is made in the form of a heat sink and the wires may fit better that way.

Chuey