1972 Z50 K3 Wiring

Chief

New Member
My stator has only one coil and only a black wire coming from it. I bought a new wiring harness and it has a plug for a black and red wire . I am running a headlight and tailight and a simple on/off light switch and a simple on/off power switch on the handlebars. There is no battery and no ignition switch. I know the black wire coming from the stator is my power wire and I believe the red outlet in the plug is for the lights, however there is no red wire coming from the stator. Is this correct or am I missing a red wire from the stator or is the black wire supposed to run the lights as well? Any advice is appreciated.
 

dirtbkr188

Well-Known Member
If you only have one coil it is solely for running the engine, period. Either a previous owner removed the lighting coil from the stator plate, or swapped in a newer year ('79-'87) Z50R stator and flywheel, which only have one coil.

Can you post a few pics of your stator and flywheel, if you don't mind?
 

Robert thran

Well-Known Member
The black wire goes to the coil that has the spark plug wire coming out of it..if you only have one coil under your magneto and if the bike runs or at least has spark then you have no light coil..someone in the past could have installed a late style stator plate for a bike that came with no lights or just stripped the lighting parts out? … the one coil inside your mag is your primary coil to fire the spark plug...if you can you post pics It will tell what’s up..
 

Robert thran

Well-Known Member
If you only have one coil it is solely for running the engine, period. Either a previous owner removed the lighting coil from the stator plate, or swapped in a newer year ('79-'87) Z50R stator and flywheel, which only have one coil.

Can you post a few pics of your stator and flywheel, if you don't mind?
Sorry dirtbkr188 we responded at about the same time .. at least are thoughts are the same
 

Chief

New Member
Thanks guys, I will try to remove the flywheel cover tomorrow, I don't have the special tool , any other way to get it off? This bike was in very rough condition and had no headlight or tailight or rear fender etc. etc. You mention the possibility of it having a later model year stator, if this happens to be the case would it then run both the engine and lights. I do get spark when I hook it up through the coil as mentioned
 

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Robert thran

Well-Known Member
Yes,,,your stator plate might have the threaded holes to mount the light coil..if so I would just buy a stator rebuild kit from dr,atv or chp, Honda nuts, eBay ect. they come with the main lead that plugs into your harness and all the parts and mounting hardware..if you hv no threaded mount holes you will need the correct stator plate … I have plenty if you need..
 

dirtbkr188

Well-Known Member
From the above information, it appears that you have a late '71 Z50K2 engine in your K3 frame. The plug in the pic doesn't look like an OEM plug coming from the stator, it may be an aftermarket one. I believe the OEM plug should have 4 wires coming from the stator, of which only two are actually used
 

kirrbby

Well-Known Member
Pretty sure that IS a K3 engine number...but the k2 and k3 stators are the same...or VERY close to the same.
Before you buy anything...you should really show us some more pics...flywheel, engine plug...and thru the holes in the flywheel...so we can glimpse the stator coil(s)

I'm betting someone just rigged(butchered) the original stator, or just the wires.
You are DEFINITELY going to want to order a flywheel puller when/if you order a stator kit...even if you DONT order a stator kit...you need the puller in your arsenal.
 

Chief

New Member
From the above information, it appears that you have a late '71 Z50K2 engine in your K3 frame. The plug in the pic doesn't look like an OEM plug coming from the stator, it may be an aftermarket one. I believe the OEM plug should have 4 wires coming from the stator, of which only two are actually used
The plug you're seeing is the plug that came on my new wiring harness, I don't actually have any plug coming from the stator presently, only a single black wire that would plug into the wiring harness black wire
 

Chief

New Member
Pretty sure that IS a K3 engine number...but the k2 and k3 stators are the same...or VERY close to the same.
Before you buy anything...you should really show us some more pics...flywheel, engine plug...and thru the holes in the flywheel...so we can glimpse the stator coil(s)

I'm betting someone just rigged(butchered) the original stator, or just the wires.
You are DEFINITELY going to want to order a flywheel puller when/if you order a stator kit...even if you DONT order a stator kit...you need the puller in your arsenal.
Here's some more pics, sorry for poor quality. I've ordered a puller and will take better pics once I have the cover off. It looks like the threaded mounts are there for a second coil.
 

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Chief

New Member
Further to my stator issue, I now have it apart and have installed a complete 2 coil setup from, I believe any early CT70. The only difference I see was the neutral light wire, which I removed as the Z50 doesn't have a neutral light. This stator has a yellow, black and green wire. By cranking over the engine , I get power on the yellow and green wires but not the black. I have attached some pics c/w the complete wiring schematic as my bike sits. I am somewhat perplexed and hope someone can help me sort it out. I have a simple two wire on/off light switch and a simple two wire on/off power switch. I thought this was going to be a fairly simple wiring job, BUT are they ever.
 

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Robert thran

Well-Known Member
The green and yellow are only for lights with wires coming from the top “ light” coil… the black wire is what runs the motor and connects to the points ,condenser, and main coil that has the spark plug lead..if you kick bike over check and see if you have spark at the plug..if not it’s most likely point gap not set , dirty or bad points, bad condenser, or bad primary coil,( lower one inside mag) that stator came off a K-1 up ct70 being it had the neutral wire present..
 

Chief

New Member
The green and yellow are only for lights with wires coming from the top “ light” coil… the black wire is what runs the motor and connects to the points ,condenser, and main coil that has the spark plug lead..if you kick bike over check and see if you have spark at the plug..if not it’s most likely point gap not set , dirty or bad points, bad condenser, or bad primary coil,( lower one inside mag) that stator came off a K-1 up ct70 being it had the neutral wire present..
Thanks for the help Robert, I hooked up my 6volt battery charger as a power source last night and I believe I have the complete light system sorted out, next is the black wire/engine , I will have to set the points and I'm sure she'll spark. Do you think I'll have any issues because of the CT70 stator I'm using?
 

Robert thran

Well-Known Member
I don’t think so when you buy the rebuild kits I think most 3 speed kits are all the same..the neutral light wire just goes to ground when the transmission is in the neutral position.
 
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