[KaosKontrol]

Ok... this is my first post here but I feel like I'm out of ideas so... here goes nothing. Sorry for the wall of text.

I bought an old kz305-a1 a few weeks ago and the guy I bought it from hooked up a battery (didn't come with it), crossed some wires onto the terminals, arced the solenoid, and the bike turned over freely. No fuel (lines were missing) so it didn't start.

Also the start button was broken. He had the key so the ignition switch is fine. There seems to be a few connections that are missing in the wires though which explains why the nothing powers on. Got a new battery for it and I don't get anything when I turn on the key. I've checked the wires that were disconnected and I get voltage coming out of most of them.

Checked the fuses and the main fuse was blown so I replaced it and still nothing. I've pulled up several wiring diagrams for the bike and none of them are readable. I'm officially stumped.

I have spare wire lying around but no clue what goes to where. Any help/ideas would be much appreciated.
I can post pictures of the bike if needed but I'll have to wait until daylight.

And before someone says that I can just get a screwdriver or something and touch the contact where the start button used to be... I've already tried it and no luck.

 

[KaosKontrol]

 

[WFO-KZ]

When you trace the yellow/blue wire coming from the negative battery terminal, where does it go?

When you trace the broken wire in the last photo, where does it go? Also where does the brown wire in the last photo go?

Please include photos of any wires coming from the positive battery terminal also.

 

[kent.forrest]

Here is a link to a shop manual for sale for your model (double-check me).

Kaw KZ305 EX305 Z250 '79-'83 Factory Service Manual ~ 045-1 | eBay

EX305A,B '83. Kawasaki Z250A,B '79-'82 Non US Model. Used Factory Service Manual. This is a Factory Kawasaki Service manual for the models and years listed above. It was printed Jan 11, 1983, Kawasaki part number 99924-1019-05.

www.ebay.com

While the ad doesn't show the table of contents and I've never used this specific manual, Kawasaki shop manuals generally contain a full section on the electrical system, with a clear and readable wiring diagram and a lot of good information on the theory and troubleshooting of each subsystem and component.

By the looks of things, this shop manual will be a big help as you move on to additional steps in resurrecting this bike to good running order. Yes, it costs a few bucks, but the time a shop manual will save in the long run makes these a really wise purchase.

 

[KaosKontrol]

When you trace the yellow/blue wire coming from the negative battery terminal, where does it go?

When you trace the broken wire in the last photo, where does it go? Also where does the brown wire in the last photo go?

Please include photos of any wires coming from the positive battery terminal also.

It seems like it decided to rain pretty much all day today and we're under a tornado warning in my area until early tomorrow morning. I'll take more pictures then and post it here.

 

[KaosKontrol]

Here is a link to a shop manual for sale for your model (double-check me).

Kaw KZ305 EX305 Z250 '79-'83 Factory Service Manual ~ 045-1 | eBay

EX305A,B '83. Kawasaki Z250A,B '79-'82 Non US Model. Used Factory Service Manual. This is a Factory Kawasaki Service manual for the models and years listed above. It was printed Jan 11, 1983, Kawasaki part number 99924-1019-05.

www.ebay.com

While the ad doesn't show the table of contents and I've never used this specific manual, Kawasaki shop manuals generally contain a full section on the electrical system, with a clear and readable wiring diagram and a lot of good information on the theory and troubleshooting of each subsystem and component.

By the looks of things, this shop manual will be a big help as you move on to additional steps in resurrecting this bike to good running order. Yes, it costs a few bucks, but the time a shop manual will save in the long run makes these a really wise purchase.

I'm currently broke at the moment due to ordering everything I might need for the bike (oil filter, oil, gaskets, seals, etc), so I'd have to wait until I get paid again, but I did save it. I have a scan of a wiring diagram for my bike but the words are unreadable due to low resolution I guess. For now, I just want to get the bike to turn over at least. I can probably figure the rest out from there.

I do have another question as a side note though. I'm planning on taking the clutch case cover off to make sure the oil/clutch filter screen insert is clean but I'm finding it hard to find just the clutch case cover gasket to buy. Would it be a bad idea to use high temp rtv gasket maker for it when I go to reassemble or would that be fine?

 

[kent.forrest]

50/50 odds the gasket on there can be reused. RTV can be used. Also gaskets can be traced/cut from suitable materials.

 

[KaosKontrol]

50/50 odds the gasket on there can be reused. RTV can be used. Also gaskets can be traced/cut from suitable materials.

Thanks for the confirmation. I thought rtv would be fine as long as it was high temp rtv but I wasn't sure.

On the subject of gaskets, the bike still has the stock carbs from the factory and finding a decent rebuild kit for them is proving to be troublesome. The most I've been able to find was a generic one that has the gasket for the float bowls. If you know of any reliable sources where I can find a full rebuild kit for the factory Keihin carbs, you would save me a ton of headache. Thanks in advance.

As you can probably tell by now, this is my first bike build/restoration. It's also my first actual motorcycle of my own. (I had a cheap Chinese maxi scooter before and it was... well...🤮)

 

[kent.forrest]

There's a Vintage section on this forum, and the first pinned post there is a list of sources for older bike parts. You may find rebuild kits there. Also Google search "rebuild" and your carb model number.


For general parts hunting, this site has a good selection of parts diagrams, including your bike:

https://www.cmsnl.com/kawasaki-kz305a1-csr-1981-usa_model15449/partslist/#.YjlMvLdlB0o

Use that to visually locate the part your after, like so:

Then use the parts diagram designation (11009) to come down to the parts list and find the full Kawasaki part number (16019024):

Once you have this OE part number, head to your Google search bar and drop "Kawasaki 16019024" and choose the Shopping results:

That's how I locate 90% of my parts orders.

 

[KaosKontrol]

There's a Vintage section on this forum, and the first pinned post there is a list of sources for older bike parts. You may find rebuild kits there. Also Google search "rebuild" and your carb model number.


For general parts hunting, this site has a good selection of parts diagrams, including your bike:

https://www.cmsnl.com/kawasaki-kz305a1-csr-1981-usa_model15449/partslist/#.YjlMvLdlB0o

Use that to visually locate the part your after, like so:

View attachment 44134


Then use the parts diagram designation (11009) to come down to the parts list and find the full Kawasaki part number (16019024):

View attachment 44135


Once you have this OE part number, head to your Google search bar and drop "Kawasaki 16019024" and choose the Shopping results:

View attachment 44136

That's how I locate 90% of my parts orders.

Thanks 👍

 

[KaosKontrol]

When you trace the yellow/blue wire coming from the negative battery terminal, where does it go?

When you trace the broken wire in the last photo, where does it go? Also where does the brown wire in the last photo go?

Please include photos of any wires coming from the positive battery terminal also.

It seems like it decided to rain pretty much all day today and we're under a tornado warning in my area until early tomorrow morning. I'll take more pictures then and post it here.

 

[KaosKontrol]

So I feel like I'm going insane here 😅
I can't understand the wiring diagram well but it looks like there should be a body ground coming from the negative terminal of the battery? The closest thing I've seen to a body ground on the bike currently is a cable coming from the transmission to the body. There's no other electrical wires going to the transmission save for the neutral light indicator on the cluster.

 

[kent.forrest]

@KaosKontrol as an electrician by trade I always cringe a bit as we all (me too) misuse the term "ground" on cars and motorcycles.

It's more accurately the "negative return" in the system. Battery (-) to engine and frame (or engine case, which bolts to frame) allows the (-) at the end of circuits to connect to frame (or engine) and eliminate the need for a lot of extra wires for the return paths needed to complete all of the circuits.

There is a direct path from battery (-) to the frame/engine on every bike I've personally worked on. Not always easily traceable as such with how harnesses route and hide things, but able to be proven with a continuity test.

Often, it's easiest to locate this connection by looking at the parts fiche. The wiring diagram is schematic in nature, but a parts fiche gives a nice visual (usually) that better helps understand the real world routing and connection of various circuits.

 

[kent.forrest]

Ok, working with no shop manual available to me, nor bike to look at .... here's my best guess how the negative return path should be.

I think part 26011 runs from battery (-) to a point on the frame, and part 26011C runs from this same point (under same bolt) to the crankcase.

It's possible frame and crankcase are reversed order in my educated guess work. But either way, both points connect to each other and then battery (-) via 26011 and 26011C.

If you can't trace this same condition on your actual bike, I am 99% confident someone has altered the return path wiring.


Anyone who knows KZ305's in the real world feel free to correct me. I'm forming my thoughts from diagrams and fiche, only.

 

[KaosKontrol]

@KaosKontrol as an electrician by trade I always cringe a bit as we all (me too) misuse the term "ground" on cars and motorcycles.

It's more accurately the "negative return" in the system. Battery (-) to frame (or engine case, which bolts to frame) allows the (-) at the end of circuits to connect to frame (or engine) and eliminate the need for a lot of extra wires for the return paths needed to complete all of the circuits.

There is a direct path from battery (-) to the frame/engine on every bike I've personally worked on. Not always easily traceable as such with how harnesses route and hide things, but usually able to be proven with a continuity test.

Often, it's easiest to locate this connection by looking at the parts fiche. The wiring diagram is schematic in nature, but a parts fiche gives a nice visual (usually) that better helps understand the real world routing and connection of various circuits.

I never understood why people called it a ground on vehicles either tbh. Rubber is an insulator against electricity so...yea. As for the parts vs diagram thing, if the words weren't so pixilated on the diagram sheet, I could probably understand most if not all of it. As it stands, I can barely make out some of the colors in the color key. I have no idea what a parts fiche is so there's that. I tried continuity on the loose/cut wires and got nothing. tried ohms test on frame and got nothing. Considered lighting the bike on fire but then I would have nothing >_>

 

[KaosKontrol]

nvm about the parts fiche thing...I just caught on to what they are. 🤦‍♂️
That aside, I officially think you draw better diagrams than the factory did. At least I can see it

Also, I would be hard-pressed to make the associations between the parts fiche and the diagram. I'm better with software on computers. Outside of that realm, I'm like an infant or a caveman: I bash things together and see the result...usually destroying the object in the process.

 

[kent.forrest]

Here's a link to the parts diagrams for your bike (confirm I got the model/year right). Us old guys with white beards call them fiche because they used to be actual microfiche.

https://www.cmsnl.com/kawasaki-kz305a1-csr-1981-usa_model15449/partslist/#.YjvtaLdlB0o

These are extremely valuable guides that I personally can't survive without.

If you do light the bike on fire I'll bring folding chairs and beers.

 

[KaosKontrol]

Here's a link to the parts diagrams for your bike (confirm I got the model/year right). Us old guys with white beards call them fiche because they used to be actual microfiche.

https://www.cmsnl.com/kawasaki-kz305a1-csr-1981-usa_model15449/partslist/#.YjvtaLdlB0o

These are extremely valuable guides that I personally can't survive without.

If you do light the bike on fire I'll bring folding chairs and beers.

Model and year look right. As for the folding chairs and beers, I'm Texan, born and bred. I keep whiskey and beer available at all times. Never know

 

[kent.forrest]

back to the top, if I'm tracking correctly, you're missing this connection and is at least one reason for the bike not starting.

 

[KaosKontrol]

back to the top, if I'm tracking correctly, you're missing this connection and is at least one reason for the bike not starting.

View attachment 44160

That's how it seems. Checked the KZRider forum and someone else had a similar problem but it affected their lights. All because one negative wire wasn't connected. Not sure if it was the (-) batt to chassis or not since they weren't too specific but still. I did get my replacement start button for my righthand controls in today and got it installed. Fun fact, it was for a kz440 or kz750 but it was listed as a horn button...which didn't really match what it looked like but whatever. That being said, I might as well get the start button working as well since I really don't like the idea of having to tear the bike halfway apart just to cross a few wires. No idea why the guy I bought it from didn't just order it off of ebay since it was only $12. Maybe just too cheap to not chop wires? 🤷‍♂️

Edit: Not quite sure what gauge wire to use for the (-)batt to chassis. I have some house wire that I can braid and sheath in shrink tubing but I'm not sure if that's even a useful idea...even as a temporary solution.