Cam Journal Wear

I have done some checks on the cam shafts on my z500 and the cam journals are past the service Limit. I assume the journals are as well.

My Question is besides replacing the Cylinder Head and cams what can be done to get them back into spec.

I have looked around and re-grinding the cams seems to be an option along with getting inserts for the caps made?

Not really sure what my options are could someone clarify or is it just less of a head ache to get new cams and a cylinder Head?

How much journal clearance is there? You can measure using plastigauge but the valves need to be out of the head to do a proper job.

Camshaft journal wear most likely won't cause any running issues unless it's excessive. There is no easy way to fix the parts short of replacing them.

I currently have only properly measure the wear on both cam shafts lobes and journals.

All the lobes are within the service limit, but most if not all journals are worn past the service limit. On average they are about 21.91mm with the service limit being 21.93mm

I intend to strip the motor down and rebuild it and have ordered some plastic gauge for when the time comes.

Are you sure it's actually that small? I've measured several 550 cams and none were close to being at the limit. Was the motor abused or have really high miles on it?

What did you use to measure the journal?
You said the "journals are past the service limit ... and assume the journals are as well".
Are you talking about the bearings in the head or the journals on the camshafts?

As Nessism said, it's not really a fixable thing, and you likely don't have to. If that's the only issue with the motor, I recommend not tearing it apart.

I would double check the measurements using a different tool just to make sure the problem is with the cam and not the tool. Ed

I measured the lobes and journals with a micrometer, taking four measurements on each journal. I intend to double check before replacing anything.

I was talking about the plain bearings in the head most likely being worn as-well, as of yet I have not checked them because I dont have a bore gauge, or appropriate plastic gauge

As for wear on the motor I am unsure. I bought it with 50k Km's on it I don't know the history of the motor, when I first started doing maintenance it looked like it has mostly been neglected. It still goes and performs well, it just makes a whole bunch or clattering and is in my opinion really loud. I just want to know what is going on as to prevent undue wear on parts.

Well, If it's not leaking oil, and seems to shift and run ok, I think I would try to set the valves, check compression to be somewhere around 160psi or higher, and see if a really good idle tuning will make it less clattery. A vac leak or bad sync or ignition can make the motor sound a lot clunkier. There's nothing to lose, really, because if the camshafts are really worn past the limit, you'd be better off saving your money for a better motor than rebuilding that one. A 550 will bolt right into the frame and use the same carbs etc.

Any work you do on the carbs or troubleshooting ignition problems will pay off on the new motor or on rebuilding this motor, whichever you end up doing.

I've never heard of inserts being made for KZ500/550 cam caps. That sounds interesting, but could also be troublesome.

I saw your post about the used motor you bought. How available are the 550 motors? Or do you want to stick with a 500 motor?

The compression is good
It does leak some oil some at the bottom end and some at the left side of the cylinder head were the oil gallery is.
It also occasionally shift out of gear for 2nd under heavy load. A neutral can also be found between 5th and 6th gear, soon after it will slip into either

I don't mind a 550 motor they are basically the same motor just bored out.
To get a 550 I would need to ship one here from america.

From what people are selling on ebay it would be costly.

The false neutral between 5th and 6th is very common on the 550's, even when the bikes had low miles.
Slipping out of 2nd is definitely a problem... might want to check the shift drum and the pawl mechanism. The pawl can be done without splitting the crankcases.

I didn't realize the 550's didn't rally make it to Australia.

Also, I didn't realize you already have another bottom end to play around with.

Yea the KZ550 was only in america, Europe had the GT500? and Australia the Z500, Practically the same bike just some minuet differences.

When I mean false neutral I didn't mean the light(poorly worded) it is like their is nothing their, As if the bike was in neutral.

Yes, not a light, but an actual neutral between 5th and 6th where the motor turns but the trans is not engaged. I've never spent more than a moment in that condition, and it was usually the result of a lazy shift.

I call it "false" because it is not the intended neutral. But I think they all have that behavior. I've had maybe one bike slipping out of 2nd maybe once out of 200 or 300 shifts from 1st to 2nd. But that is not common. If it's happening a lot, it definitely needs to be looked at.