1980 kz 750 ltd starter problems

Just got myself a 1980 750 ltd, bike doesn't seem to bad except for the starter, it turns all day but does turn the motor over, every once and a while it will engage but mostly it just spins freely, I asuming that the starter gear isn't popping out correctly , So my questions are, has any one else had this problem and what have they done to fix it, also is there a good place to get a used starter setup for this bike
thanks
Rob

1980 750 LTD twin or four (both were made that year).
Sounds to me that you think the starter is like an automobile starter, but it's not, there is no starter gear to pop out and engage a flywheel (on either four or twin). It uses a starter clutch with rollers in it to enegage via friction. Take a look at the parts diagrams on buykawasaki.com and you can see it.

Your starter clutch needs rebuilt/replaced.

i see, doesn't look to bad, you can get it out pretty easy threw the oil pan?

Assuming you have the four cylinder KZ750 LTD., the replacement of the starter clutch mechanism is considered to be a bear of a job. If you search the articles and the archives, you will find some guidance. One of our earliest and most knowledgeable members, Murphyau, includes a write-up in his articles on the KZ650 engine rebuild process [the 650 and the 750 are identical in many respects, so his information is directly on point]. Here is a link to one of his articles, and a quote:

kzrider.com/component/option,com_docman/...oc_download/gid,146/

"On these engines the starter drive clutch is also mounted deep within the engine on the jackshaft, rather than on the back of the alternator rotor. Consequently the starter motor is mounted what looks like the wrong way round, with its drive gear facing the centre of the engine. This design keeps the engine compact, but servicing the starter clutch means awkward upwards surgery through the sump or a crankcase split to access the jackshaft."


I can tell you I know of no-one who has tried to replace the starter clutch parts through the sump.

Replacing or repairing the starter clutch means removing the engine and splitting the cases if it's a 4. Guys here have done it without splitting the cases, but it's a job either way. I doubt it possible without at least removing the engine where you can work on it on a workbench.

If I needed to do this, and the engine were otherwise in good shape and not in need of an overhaul, I would try doing it through the sump, without removing the engine. Here is how I would make my attempt:

1. Drain the oil.

2. Remove the exhaust system and all of the bodywork (tank, seat, etc.).
3. Drain gas from carbs.
4. Remove the battery.
5. with the help of a buddy, turn the entire bike upside down, so it is sitting on the handlebars, and the tail part of the frame. Use crates and cardboard padding to ensure it is stable, and you do not mar the shiney bits.
6. Remove the oilpan, and all other engine components needed to reach the starter clutch mechanism. Replace parts as needed.
7. BEFORE YOU BUTTON IT UP test the starter clutch by hitting the start button. (You will need to patch in the battery to do this, of course.)
8. Reassemble in reverse order.

Even though this process has been described as performing dental work through the anus, I would try it just to avoid tearing apart the entire bike and disassembling an engine that otherwise does not need it.

Of course, all of this could be avoided if the KZ750 had a kick starter, like most of the KZ650 bikes.

Post edited by: apeman, at: 2006/02/06 20:03

Hopefully someone can help me, this last weekend I picked up an 1983 Kz750-K1 LTD (twin with a belt drive), I have a couple of questions about it, first this question is in line with this post - my electric start will not work when the motor is cold, once it warms up it works just fine Any ideas? Also were can one find a shop manual for this beast? I've located the kawa website for exploded views & part numbers but would really like a manual. Thanks for any help you can give.

alright so now i have flipped the bike over pulled the clutch plates out, clutch basket,oil pan ect, all of which didn't seem that bad,also the oil pump, now i am looking at the jack shaft with the starter clutch and the chain on it, do i pull the shifter side cover off take the cap off and tap the shaft out, will it just slide right out? also does the clutch just slide right off of the shaft,so far it seems pretty easy which leads me to believe i'm missing something. Any help would be greatly appreiciated.

alright so now i have flipped the bike over pulled the clutch plates out, clutch basket,oil pan ect, all of which didn't seem that bad,also the oil pump, now i am looking at the jack shaft with the starter clutch and the chain on it, do i pull the shifter side cover off take the cap off and tap the shaft out, will it just slide right out? also does the clutch just slide right off of the shaft,so far it seems pretty easy which leads me to believe i'm missing something. Any help would be greatly appreiciated.

So, you really dove into it from the bottom entry! I thought this would work, but didn't have the need yet to do it. (My KZ750 LTD has been making the strange starter clutch noise on start-up for at least a few thousand miles now. I thought it would stop working, but so far, so good.)

It sounds like you do not have the workshop manual, so you will need to study up from an on-line source. If you look under the "community" tab, above, then scroll down to "filebase" you will find a database of articles and information posted by kzrider members. Within that list are both a magazine article (3 installments) on the KZ650 engine strip-down, dissassemble and rebuild process, and a similar (but better) set of 3 articles (with pictures) written by our member murphyau (the smartest kz wrencher on the planet). In fact, below I post a link to them all. Somewhere in those articles is a description of how to access and refurb the starter clutch mechanism.

Go for it, and take pictures to post up on how it all worked for you. (I want a good description for when I need to attack mine!)

Here ya go:

kzrider.com/component/option,com_docman/...oc_download/gid,230/

kzrider.com/component/option,com_docman/...oc_download/gid,229/

kzrider.com/component/option,com_docman/...oc_download/gid,228/

kzrider.com/component/option,com_docman/...oc_download/gid,146/

kzrider.com/component/option,com_docman/...oc_download/gid,147/

kzrider.com/component/option,com_docman/...oc_download/gid,148/

Good luck!

kzrider.com/forum/viewthread.php?tid=9285

Actually you need to remove the secondary shaft and starter clutch anyway before you can split the cases - the secondary shaft sits in the lower case only and is tied to the crank through the primary chain, can´t pull the cases apart without removing the shaft/starter clutch.

Rspector, seems like you already have the clutch basket off, right? If not, you´ll need to remove that to get to the secondary shaft bearing retainer bracket On the right side of the engine (sitting on bike) there´s a gear sitting on the end of the secondary shaft - remove the circlip, remove the gear and remove the bearing bracket that sits behind the gear if you didn´t already. You´ll need an impact screwdriver (hammer type) to get the bracket bolts off, they´re staked.

On the opposite end of the shaft there´s a bearing cap, right behind the altenator - remove the two bolts and pry the cap of. Use a soft drift (wood or alu) and tap the shaft out from the alternator side, it should come right out. Hold on to the starter clutch assy and pull the shaft out, then release the starter clutch from the primary chain, there you go.

(The engine in the pic has the topend and jugs removed, which is why the camchain is hanging down).

Btw, I have a load of pics from when I did mine, I´ll do a write-up as soon as I can and post a pdf.

Post edited by: onkelb, at: 2006/02/08 14:47

rspector,

OnkelB has just the right information for you, with pictures. I read over one of the murphyau articles, and note the following points quoted from the article:

"The jackshaft has to come out before the crankcases are split, and with the end cap removed from the sprocket side the shaft will tap out sideways from its bearing in the lower crankcase. As it comes free the whole primary drive sprocket and starter clutch will slide sideways off the jackshaft as an assembly. With the shaft pulled clear it's then easy enough to unhook the primary chain and set aside the sprocket and starter clutch. Keep the starter clutch together at this stage, if the drive boss comes out of its housing the three drive rollers can fall out. Once it's all clear I've assembled the starter clutch back onto the jackshaft to keep all the bits together pending full examination."

Have you ordered your parts yet? I bet z1enterprises.com will be able to help you out, at the right price. If it is not on their website, call or send an email, and they will tell you if they have your parts. (kzrider member jeffsaunders is the owner of z1enterprises.)