TOPIC:

It works, but I think it might be time to address this problem on my KZ440. What do you think?

I knew it was worn down, but it all worked so I hadn't replaced it. On a short ride yesterday the bike started misfiring and acting jerky. I thought it was a fuelling problem, and yes the bike was a bit rich (it's really hot here so that doesn't bother me) so I pulled the plugs. They seemed fine. The cam chain has always been a bit noisy, so I thought perhaps it had skipped a tooth. I removed the cam cover and it hadn't.When you set the crank exactly to TDC, as you can see in this picture, the horizontal line on the cam gear is in the right place, pointing to the front of the bike in line with the cylinder head. The cam chain is basically fine. However, the notch on the camshaft end itself doesn't point in an even horizontal line towards the rear of the bike. It points down and back, by quite a big angle. This is different from the workshop manual. Plus the cam lobes don't look like the workshop manual. At TDC, the exhaust lobe is almost parallel to the top of the cylinder head, while the intake is slightly upward. The  manual shows them both as supposed to be pointed slightly upward, so this suggests really bad exhaust-side cam lobe wear.

I'm not familiar with the twins, so what do you think? I've never seen a cam so radically different from a workshop manual diagram. Should I just source a random used camshaft and stick it in, regardless of accelerated wear to the head? I haven't pulled the cam yet to measure the actual wear.

Might be 180* off. Turn it over 180 and check again. Pics of the cam lobes?
Steve

Unlikey to cam wear to the degree you mention. Either as below or possibly but unlikely sprocket wear.

The best way to tell if the cam is worn is to take it off, measure it and compare to the spec in the manual.

Are the holes on your cam sprocket slotted? My 305's were. It may just look that way due to the timing. 

Thanks guys. No more pics yet as I've put it all back together after wiggling the camshaft around and then reinstalling the CCT with a bit more tension in it. I'll have to take it all apart and have another look, as well as measure the cam lobes.

The cam lobes look good by the way. Just that exhaust-side one looks slightly flattened to the naked eye. They're all shiny with no pitting or bad scratches. However, you can feel a big, slightly rough and sharpish ridge to the edges of the cam lobes. Whether this is a crazy amount of wear or just the way they were machined, I don't know.

I think it could also be 180 degrees out, as that line on the cam gear in my photo is a flat line and not an arrow...

Your mark is not horizontal with the head, i can see that in the picture, set the ignition timing marks up at TDC,  then check camshaft marks, also adjust cam chain tension. i assume the bike has been running well up until now, if it has the timing is not 180 degrees out.

wrote:

Your mark is not horizontal with the head, i can see that in the picture, set the ignition timing marks up at TDC,  then check camshaft marks, also adjust cam chain
tension. i assume the bike has been running well up until now, if it has the timing is not 180 degrees out.
 

The mark is horizontal with the head. Maybe the blue line I put in is misleading.
Already at TDC, exactly.
Camshaft marks: notch is as seen in the pic. It faces rearward (correct) and downward (not supposed to do that, as per the diagram in the manual).

The bike has been running. Not sure about running "well" LOL. Seems a bit agricultural but does run. It started getting rough and uneven at idle when I took it for the short ride yesterday. Then cloncked out once. Started again, seemed normal but then backfiring/afterfiring - I would guess only on one cylinder.

I've had time to whip the cover off one more time. Have a look at this picture and see what you think. What's been bothering me is the angle of the exhaust cam lobe (the one closest to the camera in this pic. According to the diagram, it should be more upward-facing, like the other one next to it (intake valve cam lobe).

I've looked at it really carefully and tbh I see nothing that could be changed to make it resemble the workshop manual diagram. I'm no longer sure that this valve timing has been causing me my issues. It amounts to being less than one tooth out. The cam chain is nice and taut. To me it looks like Kawasaki intended it to be like this.
It isn't 180 degrees out. There is only that one dash mark on the cam gear .There is no arrow, nor any other markings.

I now think my misfiring issue must come from elsewhere. Possibly a vacuum leak that only appears when the cylinder head gets hot.

I've got a few tricks up my sleeve, will try an experiment tomorrow and report back.

 

Looks like the cam timing is off.  The line on the sprocket should never point below the gasket surface, it should point level or above (because as the cam chain elongates the line moves up.)

 

It's possible your cam chain is stretched, causing poor timing, but unlikely.  I would go back and look at my advancer to make sure it's working correctly and use a timing light to check timing.

A lot of people don't anything about the cams for the KZ400/440s.
The cam lobes are not symmetrical. This is because the rocker arms
slide on the cam lobes and are on opposite sides of the cam.
The typical wear caused by lack of maintainence is on the nose.
They are either pitted or worn down.


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