KZ750H Valve Lash Decreased AFTER Clearance Job? Can of worms.

wrote:

Does the base circle take up approximately 180 degrees of the lower portion of the cam? 


 

I'm not sure on the 750, but on the 550 it does not.  It makes up less than 180.  It's not always obvious from documented duration figures either.  Kawasaki specs duration at .012" if I recall, so it depends on the lead-in and lead-out ramps.

(Because of this, you cannot measure the base circle diameter directly with a caliper. You have to mount it and rotate it and measure with an indicator, then use a caliper to get the full heel-toe distance to compare against.)

 

It's not MY method, it's Kawasaki's and Suzuki's

Simple way...

Turn over engine (clockwise) using the hex under the ignition cover...

Point the #4 exhaust cam lobe forward, parallel to the gasket surface.  Then measure #4E and #3E valves
Point the #1 exhaust cam lobe forward, parallel to the gasket surface.  Then measure #1E and #2E valves

Point the #4 intake cam lobe straight up, 90 deg to gasket surface.  Then measure #4I and #3I valves.
Point the #1 intake cam lobe straight up, 90 deg. to gasket surface.  Then measure #1I and #2I valves.

No looking at T marks on the crank, etc.  Just watch the cam lobes.  

Hope this helps.

 

That seemed to help. Just took it out for a spin.

I found that I had undershimmed three valves after measuring with the better method, all 3 were ~.25. Replaced them with smaller shims.
The ticking did increase as it got warmer but not nearly as bad.

I did also see some marks on the cam journals. They didn't look bad, more like discoloration as well as some very fine aluminum/oil slurry in the guide pins (not much so maybe from the bolts?). Not great. I used some engine break-in lube and will monitor them for any changes. If they go the course of action is machine or replace the head?

For the time being I'm going to ride it a hundred miles or so and then recheck the valves, I've had the valve cover off too many times this past month.
I think i've got a couple of smaller issues to address in the meantime. (lean on 3,4/ doesn't fire up easily when warm, etc)

Thanks all for the help!

UPDATE:
I've done a cheap leakdown test, no audible leaking from valves. Visually inspected the valves at the exhaust port, they don't look damaged.
Redid the valve clearance and all are within spec.
Replaced exhaust gaskets
Dropped the oil pan and cleaned oil screen (wasn't gooped up)
Replaced clutch and oil (Lucas Oil 20w-50)
Set float levels on all 4 carbs (3 and 4 were a little low but not drastic)
Vacuum synced the carbs
Spark plug gap is correct
Coils have correct resistance (stock)

I am still getting a loud ticking noise coming from Cylinder one (used a dowl rod to locate the sound)
It does seem to be coming from beneath the cam. Weak valve spring?
The bike still isn't running as I think it should. Doesn't have a consistent idle. It seems to hesitate slightly (I can feel a dysrhythmia in the exhaust coming from 1&2)
It also has a hard time starting when hot, I have to crank it a bit and give it fuel. It also does not like full choke no matter how cold the bike is.

Possible issue:
The stock auto cam chain tensioner appears to be out of spec (The wedge sticking out is about 1/8" too far into the body)

Ordering a manual tensioner now to see if that helps.
Also plan to pull the carbs and check the mixture screws and get the float levels damn near perfect.

The bike seems to have plenty of power and does not complain on the highway (6500 rpm with 16/38 530 chain) but those RPM's seem a bit high for 70mph.

Any input is appreciated!