1978 KZ650 C2 resurrection

Hey all-

You may remember me from here: kzrider.com/forum/forum-index/10-new-mem...om-san-diego?start=0

Since getting the carbs cleaned up, I've gotten new air box boots, and basically gotten the air system rebuilt. It could use new boots going from the carbs to the engine and new t-connectors between the carbs, but I will save that for once the engine starts, if it ever does.

I got a new key barrel, cleaned and redid the wiring for the run switch, and overall did a little cleaning tidying. Got a new air filter, have new oil and oil filter ready to go for when it's time, and spark plugs are in the mail.

Recently I got a battery for it (didn't come with one) and I charged it and hooked it up today. And I hit exactly the point I have been dreading this whole time: basically nothing works. I'm of course not trying to start the engine without oil/filter/plugs/checking the points and condensers, but with the battery on, the only thing that works is the right rear turn signal, and it doesn't flash.

No headlight, brake light, "dash" lights, nothing.The fuses look ok to me. Now it's entirely possible just all the bulbs are fried, especially in the guages, but I'm really worried the whole wiring harness is just trash and needs to be redone. And given that I would have to learn how to do that from scratch, I'm super hesitant to invest all the time into that just to not have the engine start for some other reason. But without doing that, I've got the feeling the engine won't start either.

For reference, this bike sat in a garage for over 30 years, and then sat outside on a porch in the desert for a handful of years.

I'm super discouraged at this point. Does anyone have any advice/encouragement for me? I'm a pretty smart and handy guy, but I am starting from absolute scratch with zero knowledge. How difficult would it be to re-do all the wiring, just following the wiring diagram and what's already on the bike? I can't seem to find what gauge/type of wire to use, or where to get the relays and flashers and other fiddley little bits that go into it. I've tried several times to find instructions on how to bypass as much of the wiring as possible to just start the engine, but that knowledge seems to be reserved for people who already know how to do it.

Here's the bike with the cleaned up carbs and some grips on it, looking a bit more together than before.

I sat down with the wiring diagram, and I found a spot where it looks like someone tried to be clever and modify the harness at some point... but did it wrong. There's a female end of a plug in a spot where there shouldn't be, and nothing to connect it to. Looks like redoing the wiring is going to be in my future.

So, an elementary question: what kind of wire do I need? I've searched before, and the answer eludes me.

edit:

Well... maybe not. I looked at the color wiring diagram instead of the one in my service manual, and I found the suspicious pieces. Why are these here? Especially the grey/green plug?



Though I am definitely missing the lockout switch on the clutch,and I am guessing the inside of that control may be a mess as a result. I'll try to take it apart soon.

Well... maybe not. I looked at the color wiring diagram instead of the one in my service manual, and I found the suspicious pieces. Why are these here? Especially the grey/green plug?

Looks like an optional connector/connections for a turn light beeper.

Those are for optional factory light accessories that came with the factory optional windjammer fairing - they are vesitgial in your case.

Most of the circuits here will be OK with 18ga wire. however certain circuits like 12V+ from battery to key switch will need to be 14ga - if your harness is intact just replace what you need to with the same gauge wire or thicker. I recommend using OEM style 4mm bullet connectors however generic 4mm bullets that you can get at most auto parts store will work as well. you will need the appropriate crimp tool as well - vintageconnections.com/Products/Terminals

Do you have a factory manual and a multi meter or a wire probe? I would start checking that power is making it through all your switches. its common for the handlebar switches to corrode and not pass power. start at the battery and work your way through the fuses to the key switch and out through each circuit. the factory manual has guides for checking most systems.

 

Got it, thank you guys! This is really helpful. I do have a multimeter, I don't really know how to use it, but now's the time to learn, and I'm fully capable.

The wiring in the left hand controls "looks good", so testing with a multimeter is the next step. May take me a bit to learn and get it done, but I will report back! Thanks again!

Be sure to use your meter on the fuses. Age and vibration can cause the solder that holds in the link to let go. One end of the link inside the glass tube can be completely disconnected. It is almost impossible to see this through the glass, so only your meter can tell for sure.

wrote:

Be sure to use your meter on the fuses. Age and vibration can cause the solder that holds in the link to let go. One end of the link inside the glass tube can be completely disconnected. It is almost impossible to see this through the glass, so only your meter can tell for sure.T
 

Thank you! I'll start there.

I know it's taken me forever to do something so simple, but one of the fuses was indeed bad, so I've replaced the fuse box with a blade fuse box. Need to pick up another 10A blade fuse, so it's not on the bike yet.

In the meantime, does anyone have a picture of where the battery vent tube routes to? I see the little spot that holds it to the battery box, but I need to get a new tube itself, and need to see how long of one I should get. I doubt it should drip onto the swingarm, but not sure where it goes below the battery box? Does it go the same place as the carb overflow tubes?

Yes.  just make sure to the tubing is routed away from the drive chain & mufflers.

Engine is running!!!



It's not running well, but that's ok for now! I only ran it for a few seconds. Next steps are getting the tank and muffler into service-able condition, getting a dynatek ignition on it, and maybe upgrading the reg/rec to get a li-ion battery. Then it'll be restoring all of the brake system and getting a chain and sprocket... then new tires... lots of work to do!