KZ750 Twin Won't Start, STILL wont start!! Updated

No eBay APP ID and/or Cert ID defined in Kunena configurationmaybe you have to tell them what bike you need it for so they will send you the corrct kit

750steve wrote: Also, the 2nd pic in this advert;
cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem...trksid=p5197.c0.m619

& the pic in this advert are the same.


..........the reason i went for the 1st one is the $20 difference in shipping to the UK


They could all possible be the same internals instead of making different ones? I dunno, just guessing but it does say in the list it will fit my bike. I do see your point though.

True! I've sent the seller a message

Well i just put the starter back together & its now working!!

Rebuild kit on its way now though so i might as well do it when it arrives. I have no idea what the broken piece was that i took out earlier as mentioned.

The offending item. Anyone recognise it?

*EDIT* After having more knowledge on completion of this thread & anyone is reading this that is going through a similar situation DO NOT throw this small piece of metal out like i nearly did..........read on to see why!

Ok, so i took the motor apart, cleaned it up & it spun ok when i put 12v to it. Still doing this though!



Steve, the planetary gear you're talking about, it's the larger 1 right?, the armeture nose (spelling??) connects with 2 small gears which spin against the outer gear. Is it this large outer gear that should be connected to the outer case? If it is i cant see how it is fixed to it, do i use a threadlock or bearing seal or something? It seems to be grooved to sit in a 'cup' with some lugs on it, but the large gear spins?

Hopefully these videos will help explain what is happening

I don't have a twin to compare it to. But I did watch your Vids, and that doesn't look right. Tell us when you hold the output gear, which would be where the chain rides, and turn it does the starter motor turn? It doesn't look like it would. That Sun gear, was it showing signs of scoring on the outside wear it rides in that end housing? I would think the Sun gear should be stationary, and the planets be the reduction. Show a picture of the output gear/ shaft. Where it goes and is driven by the planets.

Yes the starter will turn when i physically use my fingers to do it. The 'sun' gear does show signs of wear, only slightly & i believe it should not be moving inside the outer casing, you can see me turning it with my thumbs in my video. When i put 12v through the motor it performs as it should, what i think is happening is the resistance to turn the motor over is making the sun gear spin inside the body of the starter instead of turning the engine over.

Im not sure of what you want me to show in the pic you're asking for, the armature (the bit that spins inside the starter to drive the planet gears) nose goes into the planet gears & spins them, this in turn spins the final output nose where the chain rides, when the resistance is too much i believe the sun gear is spinning instead of the output nose where the chain rides.

What i dont know is how to stop the sun gear moving & i cant see how it can be 'fixed' to the outer casing??

Yes I believe you are correct, that sun gear would have been pressed into that Housing, from what I see out there. I did a Mazda starter similar to yours not that long ago. The sun is pressed into that end housing.
Wouldn't you say that if the Sun was held in place that the drive force would be transferred to the output? As this Sun and Planets are just reduction gears for the high compression of the bigger twin cylinders. I wonder if it could be welded in place?
Not uncommon to upgrade to a reduction starter on a High compression street machine.

Yes, that is correct. If the sun gear were to be held in place the drive would be transferred to the output shaft. I dont know if it can be welded but i'll look into it. Can it be re-pressed back in?

What is the reduction starter upgrade you mention? I've never heard of it.

The upgrade I mentioned is for Street Machines and not Bikes. Just through it in, sorry if it confused you. Just that technology has changed for those old cars we like. So an upgrade is available.
If it could be welded, it would have to be in the correct position or biding of the gear set would occur. Repressing, well maybe if the outside of the Sun and the Inside of the End Housing were Knurled. Then a Locking agent such as The Red Stud and Bearing Mount From Lock-tite was applied.
If your town has a Rebuilder he might be able to source up the new End Housing with Sun Gear? We have 1 in town, and the guy Knows his stuff, been there a very long time.
Does that Starter Motor Have a Brand and # besides the Kawasaki? Like Nippon Denso or something?

I havent seen any name on it, nothing comes to mind.

There's no chance of a rebuilder here! It'd be cheaper buying a new motor if i were to post it away to be fixed as well.

Pressing i doubt will work, i dont see how the 2 would 'grip' or mate into each other permanently. I had hoped some kind of locking agent or glue may work but i think thats a tall order with the force it'll be put under.

Welding too will prob not work as the weld wouldn't be 'fine' enough as not to restrict things, it wold also have to be done on the inside of the sun gearing as you look down on it as there is no room between it & the outer casing. If it is welded inside the sun gears will then catch on the weld im sure.

Oh dear!!!