75 cb750 battery/e-start delete.

TCOR1989

New Member
I searched around for a bit and can't seem to find what I'm looking for.

I have a 75 cb750f.

I want to delete the battery, starter solenoid, kill switch, and start button.
In a perfect world I'd be able to wire in a simple keyed ignition to use as kill switch. Turn the key and kick is what I'm aiming for.
Is this do-able? Or do those components need to stay for any reason?


Thanks in advance!
 

irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
You need a battery eliminator. A capacitor like this...



I still use a very small battery on my 78 CB750 chopper, one that won't crank it with electric start but is fine for running. I removed the starter, then machined a plug to fill the hole. You can find an expansion plug to fit your hole...



So, mine is kick only with minimal electrical bits and just a toggle for on/off. No starter button or anything on the handlebars.
 

TCOR1989

New Member
irk miller said:
You need a battery eliminator. A capacitor like this...



I still use a very small battery on my 78 CB750 chopper, one that won't crank it with electric start but is fine for running. I removed the starter, then machined a plug to fill the hole. You can find an expansion plug to fit your hole...



So, mine is kick only with minimal electrical bits and just a toggle for on/off. No starter button or anything on the handlebars.
I saw that eliminator, but my bike is already completely tore down, and harness disassembled..... I was hoping to get rid of some of that mess by wiring from scratch.

I was hoping to run like this, but not sure if I need the solenoid and all the other stuff.

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TCOR1989

New Member
pidjones said:
No starter = nothing to connect a starter solenoid to.
That's what I was thinking. But would I need a battery/battery eliminator to complete the circut? Or can I just go from stator to reg/rec to coils?

Thanks again guys. Electricity hates me. Haha

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TCOR1989

New Member
Alright, I think I figured it out. I DO need the eliminator, but I can bypass everything else.
Just found this and it's starting to sink in.

Thanks guys.


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teazer

Active Member
DTT BOTM WINNER
Q: does your bike have a permanent magnet alternator or does it use field coils? That will answer your question about a battery. Ask Irk why he uses a battery and look at the FSM for more clues.

The system that is shown in that last wiring diagram has a rotating (permanent) magnet and would not need a battery. Your bike, not so much. :-(
 

Sonreir

Oregon
+1 to what teazer said. Your bike has an electromagnetic alternator and so you cannot eliminate the battery. You can run a pretty small one if your charging system is in good health, though.
 

TCOR1989

New Member
Sonreir said:
+1 to what teazer said. Your bike has an electromagnetic alternator and so you cannot eliminate the battery. You can run a pretty small one if your charging system is in good health, though.
So the battery eliminator wouldn't work for me then. Bummer. Recieved guys

Thanks.

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irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
Yeah, sorry. I should've been clearer when I explained my chopper setup and why. I would much rather get rid of a battery all together. If you trust your wiring to be in good order, and your charging system good enough not to kill a LiFePO4 battery, you can get one that will hide in an inconspicuous place like under your tank.
 

Sonreir

Oregon
It can be used in place of a battery on some motorcycles that have permanent magnet alternators and a kick start. It's basically a large capacitor that helps smooth out the voltage.

When your bike is running, the generation of electricity is not constant. It actually fluctuates as the engine rotates and sometimes it's a bit too much power than needed and sometimes it's a bit too little. The voltage regulator tries to keep things in check as best it can, but a battery (or battery eliminator) is also a piece of the puzzle.
 

irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
Yeah, the generator/field coil descriptor is key. Our 750s have field coils. Unfortunately, those field coils are one of the achilles heels in the 750s charging system. They are known to go bad as the epoxy breaks down around the windings and they start burning up to gain resistance. I think having them exposed to hot oil is the source of their demise over time.
 

TCOR1989

New Member
Re: 75 cb750 battery/e-start delete.

Ok so I do have to run a battery..... Got it.

I can still ditch starter and it's components.

Now looking for suggestions for a safe lo-pro battery that won't eff my bike up.

That battery mentioned earlier (lifePO4) sounded like there were strings attached lol.


I just wanna keep it small.


Thanks.

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TCOR1989

New Member
Just wanna say thanks a ton for explanations guys. I can be a lil dense sometimes.

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Sonreir

Oregon
Gotta say... I'm not a fan of how that battery eliminator is being advertised. Some of those claims are dubious...
 

TCOR1989

New Member
Sonreir said:
Gotta say... I'm not a fan of how that battery eliminator is being advertised. Some of those claims are dubious...
That's what I thought.

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irk miller

You've been mostly-dead all day.
DTT BOTM WINNER
Sonrier can let you in on the specifics to the Earth X batteries he sells. I have killed two Shorai LiFePO4 batteries from accidentally leaving a switch on and draining them. My fault, but I want things dummy proof (me being the dummy). I have two Battery Tender LiFePO4 batteries, which is what I have on a CB550 i just built. They have special protection circuitry, so when you let them discharge accidentally, the circuit actually shuts the battery off and you have to hit a reset button to run again. Once reset, you can go back into charge mode and bring it back up again. I tried to do the first start/tune on that bike with the Battery Tender battery (like I said, me the dummy), and all the starting discharged quite a bit of battery, so I learned all about it's protection circuitry right away.
 
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