HELP!!

[blemar93]

I am building a custom cb750c 1981. I have no clue if what i have for the motor is enough to get it running or anything like that. what i know i have: motor (which i think is complete), coils for spark plugs, carbs, and a few misc items that i am not completely sure what they are. i know the general basics of wiring if given a diagram, which TOOLS1 gave me in another thread, but i am completely lost on what i will need and if it is even possible to find the stuff to make it run. i am on the verge of just scrapping it and getting a different motor because i am so confused, but i would like to keep it cause it is a cool motor and most of the mods we did were cause of the motor.

If anyone could list (i mean detailed with maybe pictures of some of the items) that would be great or direct where to find what i need or get what i need. I wanna get the bike running sooner rather than later but i cant find much.

any help is appreciated.

thankss

[surfish95747]

Put up pictures of what you have that might help.

[blemar93]

Here are some photos. not pictured is a box of misc stuff that has some wiring in it and stuff that probably cannot be reused.

p.s. the last photo is how the bike is coming along. not to much frame work left then powder coat and paint the "tins" and then the dreadful task....engine work....

[TOOLS1]

WOW!!!! I am loving it!!!! That mono shock is awesome!
Some pictures of the wiring you have would help. You will need igniters for the ignition, reg/rectifier, battery, and solenoid. I always try to use as much of the stock wiring harness on a custom build as I can. I just strip it of any unneeded wires, and then shorten/lengthen as needed.
TOOLS

[shinyribs]

Download the Factory service Manual. FSM. It will show you all of the pieces you need to get the bike running. Like Tools said, yu still need the CDI boxes/igniters. And of course, a battery and starter solenoid. You're very close. Don't give up. These are great, reliable motors with more bottom end power than most old Japanese inline fours. IMO, it'll be the perfect motor for a build like this.


And ditto on your rear susp. Awesome. Reminds me of vintage dirtbikes with that high mounted mono. Too cool,man. If you dump this project (and we are semi-local to one another) give me a shout. I'm interested. But please dont give up.... I don't need another orphan.

[blemar93]

this is all the wiring i have. there is a start button assembly with the throttle cables as well.

thanks

[TOOLS1]

I cannot tell if the thing on the left is an ignition switch, or the starter solenoid, however you have plenty of coils, and the brake pedal will come in handy. The gray things with the red wire covers are your ignition ignitors. Also it looks like you have most of the wire harness, and that will come in handy. You will need the reg/rectifier yet. The hard part about wiring a custom bike, is making it look good.
TOOLS

[blemar93]

http://www.ebay.com/itm/NEW-VOLTAGE-REGULATOR-RECTIFIER-FOR-HONDA-CB750C-CUSTOM-CB750F-SUPER-SPORT-/361300823913?hash=item541f350f69&vxp=mtr


this is what else i need right?! is there a place to get it cheaper?

[TOOLS1]

That's it. You might find a used one cheaper. Vintage has it for $125.00 http://www.vintagecb750.com/products/5/electrical/55/wiring-harnesses-and-charging-system-parts
TOOLS

[blemar93]

so after i have that in hand and a battery i should be able to get the motor running?

[TOOLS1]

You do not need the reg/rec to start the engine, just to keep the battery charged.
TOOLS

[blemar93]

but with everything i have there i should be able to get it running? sorry but with the way the wiring is i am still really confused haha

[TOOLS1]

You have everything you need to start the engine.
TOOLS

[blemar93]

thanks TOOLS. i will post more questions if i cannot get the engine started

[blemar93]

I still feel like i am missing a lot of wiring for this motor...i have no idea what to even look for if i am missing components. i have a battery now but do not know where to hook it up to. should i just buy a new harness? this is stressing me out.


thanks

[TOOLS1]

Battery ground goes to the engine case, and the positive goes to the other terminal on the solenoid. All the dark green wires are ground.
TOOLS

[blemar93]

do i need an ignition or something to push/turn to get the motor to turn over? or after i hook up the battery will it just turn over?

[TOOLS1]

Just ground one of the small wires coming off the solenoid, and then when you touch the other one to the positive lug on the solenoid (the lug with the big wire going to the battery) it will engage the starter.
Also here is the wiring diagram again. Just run wires to where it shows them going. Its like reading a road map.

TOOLS

[motogrady]

I'd be stressed too.

Most of the electrics are located behind the motor, under the seat.

I'd set the motor in the frame, just sitting there, and start with mounting the coils wherever the wires reach from the plugs.

Mount the battery, you're gonna need to feed the electrics on the left side, that's where the timing stuff is.
An on/off switch would do. Turn the switch on to feed the distributor from the hot side of the battery.
That feeds the coils, which feed the plugs.

The starter, on a stock bike it's a push button on the throttle grip assembly.
I don't see why you could not get a push button switch, spring loaded toggle, or just touch the wire from the positive side of the starter to the positive side of the battery. One side of the starter goes to ground, one side of the battery goes to ground, hit the hot side and the starter should spin.

Lights, same thing.  Hot side of the battery, to a switch, to the lights, to ground.

You,re gonna have to rig up some kind of brake light switch.
Hot side of the battery, to the switch, to the rear light, to ground.

Same with a horn.

Those square things, spark ignitors or something like that.  Tools can tell you where they come in.

The charging stuff is on the right side of the motor, 4wires that wrap around the rear of the bike
To the rectifier and battery.  You don't need that stuff yet, it'll run without a charging system, as long as the battery is feeding the distributor side.  Constant loss it think they call it.  I used to carry a spare battery
Before I figured out the charging stuff, you'd be surprised how far you can go on a fully charged battery, as long as the lights are off.

Don't give up, any motor is gonna be a challenge to custom wire, might as well be this one.

One step at a time, good luck guy.

[TOOLS1]

Here are some pictures of the wiring on a bike I just built. I wired it all from scratch. It looks overwhelming, but like I said, the hard part is making it look neat.



TOOLS