Won't Start

Can't get my 1988 ZN1300 to start. It has a brand new battery and will crank slightly, but then will just click. Also the cables and solenoid get hot to the touch after a minute or so. I took the starter apart and found the insulation on the brush wires was gone and it smelled like cheap cigars. I cleaned it up and taped the wires. I also replaced the solenoid with another and same issue.

Suggestions?

Sounds like resistance is building up somewhere or too much current draw due to a short. I'd trace ALL the ground and positive wires and cables and make sure all contacts are spotless clean from any oxidization and smear some diarlutic , diar.. shit. What's the name for this grease? haha
I'd test the starter off the engine - to make sure it spins strong in independent conditions. Eliminating starter itself issue will narrow things down.
I'd go from there.

The brush wires don't usually have any insulation - unless I'm misunderstanding what you're referring too?? (this is an example)

Did you check the starer motor, i.e. apply 12V, while it was out of the bike ? Have you tried bypassing the solenoid with a jumper wire?

If your cables and solenoid are heating up then you have a lot of current flowing and usually that indicates a short. If someone was running the starter for bursts longer than 20 seconds and not letting the starter cool down for a couple of minutes before trying again, then the likelihood is the armature winding insulation has melted.


Simple check here would be to check the commutator ring on the armature to the shaft on the armature with an ohmmeter. If there is continuity between the 2 then the armature insulation has broken down and there's a short in the armature between the windings and the plates in the armature itself.. Armature rewinding is a common practice and is not that expensive. You could probably get the armature rewound for about $100 Canadian. (It's been a while since I had this done) The other option is to pick up a used starter but you're taking a chance here. As mentioned before, the common understood among us mechanics is 20 seconds running , 2 minutes resting or pay the consequences.


On most starters, the brushes typically don't have insulation on the wires although I have seen plastic insulating tubes over those brush wires as well. I'm talking about starters in general and not specifically KZ starters.


At his point I would also suggest pulling the solenoid apart and having a look at the contacts of the solenoid. Arcing across the faces will increase the resistance across the contacts. Most contacts are just bare copper and can be cleaned up with a file and then wet/dry paper. They usually have a slightly convex face. Some solenoid contact faces are silver faced and I have had good success with building up the faces with solver solder (Sil-Fos) and then dressing up the faces. I would only do this to save a "no longer available" solenoid on a restoration. In this case, if the solenoid is bad and the contacts can't be cleaned up leaving enough material on the contact faces, just replace the solenoid with a similar one. It's not rocket science here.

I reconditioned my starter relay about 1 1/2 years ago and wrote something about this if you do a search here.
First thing I'd do is remove your "tape" from the brush-leads. It'll end up melting off and getting stuck, somewhere......! Some motors I've seen do not have insulation and those that do have a high-temp woven sleeve that is designed for high temp. Electrical tape is not rated for this use..
As has been pointed out: battery terminals, BIG terminals on the relay, starter + terminal, brushes and commutators (Russian potatoes?) must be clean. Starter bearing/bushing must be free obviously.
As KB pointed out - you might have a short in the starter armature so when you have it apart to remove the tape - check for this concern with a meter.
A valid point regarding fitting another used relay as it could have burnt contacts, too. These come apart easily ! Recondition the relay, then move on to further dissecting the starter motor. This is fairly basic stuff and should be well within the skill-set of most.
A new starter would be a better option over re-winding. I think KB might be a bit optimistic about a rewind for $100.00.

I thought the solenoid was sealed and not serviceable. I don't recall seeing a way to open it up. The ZN1300 might be different from the KZ1300. As far as testing the starter goes. I really don't know what the commutator ring is. Is it the plate the brushes mount to? Sorry, but I'm not totally up on the lingo. When I opened the starter up there was a brown sticky residue over most of the internals. I cleaned it out and put it back together. When I take the plugs out it spins great.