KZ750 Spectre - hot engine and clutch rattle

Hi everyone,
I'm new here and need some help please

I am trying to help a female friend of mine with her KZ750 Spectre.

The issues are:
1) when bike is first started from cold and is warming up the clutch is very noisy and rattles, owner has been told this is normal (?) but it sounds awful. Have replaced clutch outer drum as it was found to be broken, and needle roller cage. Also the clutch does not operate at the lever end as it should do, it is very, very stiff, I've tried adjusting it but it doesn't make any difference. I have ordered a new cable.
Any ideas folks? I can't see anything wrong with the clutch, so I'm stumped, could it be the shaft drive?
2) From starting the engine seems to run very hot very quickly (even in winter). I would be surprised if this is normal, it does seem to get excessively hot very quickly in my opinion.

All help, gratefully received as my friend is relying on me to get her bike running for Summer, no pressure!

Cheers
Pete

Hi, what mileage has the bike done? has it been looked after well? What OIL are you using? Id try changing theoil to a 10-40 motorcycle specific brand and see if that helps things. It will run hot its an engine they create a lot of heat . Put up some pictures so we can give a better diagnosis

Thanks

Thanks for the reply.
It has done 26K (kilometres)
I believe it has had a hard life judging by the bodges I have found.

Can I just say I have been motorcycling since I was 16, I'm 60 now, so the bike has the correct oil and I know the difference between a hot engine from normal running and one that seems to be getting hot rather quickly

What picture did you want that could assist with an answer?

Anyone else have any thoughts?

Cheers
Pete

Besides investigating the several possible overheating causes listed in the FSM troubleshooting section, would assure proper functioning of the advancer, and that the drive shaft isn't dragging.

Does the rapid onset of overheating occur before or after getting underway, or either?

Good Fortune!

Are you using the Kawasaki factory service manual? I'm curious if it has an adjustment procedure for the clutch itself (separate from the cable adjustment). I'm asking because some shaft drive models have a different release mechanism than most KZs.

For models with a similar clutch actuator, manuals usually say to do the cable adjustment, but if that doesn't work, replace the cable. The troubleshooting section of the Spectre FSM may have a list of suggestions for clutch troubles.

I've still not managed to resolve the suspected clutch rattle issue/transmission noise.

The bike sounds awful when in neutral and ticking over. Once 2000 revs is reached the noise disappears.

I've replaced the clutch cable with a genuine Kawasaki item and that is no longer stiff.
I have a Haynes Manual but that doesn't suggest anything.

I've stripped the engine checked the big ends and there is no play whatsover and nothing visually wrong.

The primary chain is also within tolerance and am reluctant to suggest replacement because the cost is 230 euros for a new one and that might not be the problem. I've never known one of these to wear out at low mileage expecially when I consider the good condition of the crank etc, but I am running out of ideas.

Secondary shaft all looks fine, bearings are good.
Clutch outer and inner drums have been replaced.

The owner says she gets vibrations through the footrests, which would steer me to the big ends normally, but I've checked those.

Any thoughts/ideas gratefully received.

Have you synced the carbs? If they are out of sync you can get some bad noises at low rpm. Ed

Exactly, the engine will stumble and even fight itself to run causing frightening noises.
Steve

No, I am suspicious of them but this is a horrid knocking/rattle low down, the kind that makes you want to stop running the bike immediately!

The primary chain on the 750s are known to rattle a bit and will rattle like a proverbial bag of hammers if the carbs are out of synch. Also noticeable if the idle is set to low. I would need to check the manual but I believe recommended idle is 1100 - 1300. I would guess mine is at about 1250. Rattle is noticeable when first starting the bike until it warms a bit. Goes away once on the road . Primary chain rattle should go away once out on the street.
Primary chain rattle sounds like its coming from the transmission area rather than the clutch area. Have you tried mechanics stethescope .- big screwdriver with the blade on the case and the fat plastic handle to your ear.
Mine has been like this for the past 40,000 km and 10+ years

If not done already I would suggest trying a carb synch and see if the rattke reduces. I would not expect it to dissapear entirely if is indee the primary chain rattle.

Ok, engine back together and carbs synch it is then

Yes have done the mechanics stethescope

Will let you know how I get on

Many thanks everyone

Hey Boris,

I don't know how much difference or similarity there is between the '750 and '550 that I have but I have this same noise. It's been there since the bike was given to me as a gift about a month ago. Same sounds (rattle or clanking/clunking) at low idle and in particular when the bike is cold at start-up. Once warmed up and running it seems to go away.
I tried checking and adjusting the valve gaps to factory spec. No difference. I was going to try changing the oil next to see if that was somehow related. I haven't tried synchronizing the carburetors yet as I wanted to replace the manifold/mounts first since they're old looking.

BUT, here's more on this noise I have found in my own searches...

RonKZ650 wrote: It might just be your carburetors. When you say "they need cleaned", it may just be that and a sync problem. The 650 will rattle to beat heck from the primary chain if the carbs are not syncronized. This is where the 900/1000 is "better", if the carbs on them are all fouled up, the bike may run poor, idle poor, but no rattle because of the gear drive vs the hyvo chain on the 650. A rattling hyvo chain does not necessarilly mean it's bad, if the bike is not running correctly even a new chain will rattle because there is no tensioner on this chain. Of course as the miles rack up the chain gets progressively more stretched and the need for correct carb tuning gets more important to keep the rattle down. Other possibilitys could be a worn cam chain or those idler sprockets on the cam chain going bad and losing their centers. Just for info, I got 135,000 miles before the sprockets went bad, 150,000 out of the original canchain, 165,000 on the original hyvo primary drive chain and it was still rolling, but getting perty noisy . Finally retired that engine from service.

and this one in particular caught my attention because the description - "coffee can full of bolts" - probably the best description ever!:

ronboskz650sr wrote: Mine sonded like a coffe can full of bolts until I synched the carbs. After that, it was rattling slightly from the cam chain. I modified the tensioner (see archives)and it stopped rattling altogether. I'm glad to here the mileage testimonials on chain wear. Thanks, Ron. Any special treatment to get that kind of life?

I have the new carb mounts ordered from Z1E already shipping, so once I get that done, I'll let you know if the sync makes a difference.

Ultimately, this bike pulls like a freight train and I can go zero to scared shitless in under 2 seconds if I want to, which is why I don't think it's related in any way to valves/timing. It's not a "unhappy engine" sound. It's more like an interference sound and it's definitely in the area of the "HYVO chain". For me, I can kneel down on the right side of the bike and put my finger just around the oil-level bubble and say it's coming from in there.