Topic: Electrical troubles in starting the engine

[Jcold98]

Hi guys, Im still a bit new to the forum with this being my second or third post but I believe I’m really close to starting the engine of my project 72 cb750. As of right now the engine is sitting on a cheapy engine with complete carbs, air filters, and exhaust intact. I have also just installed the Dyna s ignition system along with the magna coils and wires, as well as new plugs too.

Where my problem lies is in the wiring. Ive begun connecting wires purely based on wiring diagrams found online. Not to mention the previous owner really butchered this harness, luckily a majority of everything looks to be here and intact. I have the entire left hand controls and their components as well as the indicator bulb’s wiring set elsewhere to alleviate some of the headache.

So with the right hand I have

Yellow/red- has to do with ignition
Black/red- ?, connected with rest of harness
Black/white- kill switch, has 12v when on, 0 when off
Brown/white- DRL?
Green/red- ground wire
I also have the engine 8pin connector plugged in

With everything stated above hooked up to the best of my ability I was able to get the starter solenoid to click as well as show 0 resistance with a multimeter test. But nothing from the starter that is, if im putting that starter wire in the right place. I just assumed it connected to the opposite pole of the solenoid.

Does my starter need to be replaced? Rebuilt?

What needs to be done to be able to kickstart the engine, bypassing the starter, or will that not work?

Ive also tried getting an open plug wire to arc to the terminal of the spark plug to see if I have a spark, of course nothing so I need to fix that too.

All of the wiring purposes are just to the best of my knowledge so more than likely I’m wrong somewhere. Im definitely no expert, I’m still learning everything so any help, tips, advice, its all greatly appreciated thank you guys.

[Jcold98]

Updating with pictures

[calj737]

Sitting on an engine stand, you need power to the Dyna ifntjin, cloud, and to the Starter motor (via solenoid for electric start). You probably want to ground the engine to the battery NEG terminal also. Power the ignition and coils, and it should kickstart easily.

[Bodi]

The wiring for a test stand is super simple. OK, maybe just simple...
Battery "-" goes to the engine case, a heavy gauge wire (8 AWG or bigger). Battery "+" to one stud terminal on the solenoid relay and take a wire from that terminal to power everything else: you should add an inline fuse near the solenoid, 20A is good. Starter motor cable goes to the other solenoid stud terminal. You don't really need the control pods hooked up. The engine plug has the alternator wires and the neutral switch + oil pressure switch wires, not needed for a quick test. Power the ignition from the fuse, have some way to disconnect it in a hurry if the engine sticks at WOT.
The wires from the solenoid: one goes to the engine case or battery "-". The other one, through a starter switch, goes to the fuse. Polarity does not matter.
If the solenoid clicks but no starter action, try jamming a screwdriver shaft between the studs to complete the starter circuit... you should see a nice spark there and the starter should spin. Spins? Solenoid is bad. No spin? Starter or its wiring is bad. The solenoid relay can be disassembled to dress the contact bar and stud ends (with a file), clean the insides and use some dielectric grease to lube the moving parts.