kz900 strange engine noise

PLUMMEN wrote:

start up is when the damage ocurs over the years .when the motor heats up thinning out oil causing clearance issues to show up.

Then you suggest that problem is on the right side of the camshaft or valves. But how to explain that sound desapier when I lean bike to the right?
And knocking periods are 100 times/min at 1000rpm. My crankshaft has 15 teeth and camshaft gear has 30 teeth. That means that camshafts turns 500 times/min at 1000rpm.
I assume that bad camshafts will be producing some faster knocking.

more oil getting to right side of engine when you lean it that way,im just giving some ideas its hard telling without bike sitting in front of me.

Possibly right side blocked oil passage? Hmmm... me wonder.

Here is a new video. My camera captures all the possible sounds but I think you can distinguish this hard knocking from other sounds. I tried to show how knocking disappears when I push bike to the right, and how it shows up again when I return bike back to starting position on side stand.




Is it possible to identify this sound now?

id say pull valve cover off and rig a temp gas tank up so you can run it with tank and valve cover off and watch valvetrain parts to see where oil is going.man that is one purdy motor youve got there!

I removed cams, tappets and shims. what do you think about their condition?

These are tappets and shims from exhaust cam side

the other side of ex. shims

These are tappets and shims from inlet cam side

the other side of in. shims

It seems to me, that someone grind out some of the shims but I dont know can this be the reason for noise from the head.
Is it possible that for some reason, ex. cam moves left, right and hits positioner on the left side?

I've been reading this thread with great interest. Beautiful bike! I went through a nightmare with my 1000 years ago as I went through 3 sets of cams (exhaust #2 cyl kept grinding flat) as OMR mentioned I would definitely check your oil galley clearances on the cylinder & head for obstruction, did you use any gasket silicone (tube type)sealer on your block or cylinder during assembly? I installed an oil pressure gauge (see pic) and they are a great thing to have... you shd be running no less than @ 5 PSI at the gauge. The oil pump ring gear does have a fair amount of play shifter side to kick starter side (left to right) @ 1/8". I would dump your oil and check it again, better still, pull your oil pan and have a look at your oil pump (I'm wondering if it could be partially obstructed from a piece of cam chain tentioner plastic) I really don't like the look of the damage on your lower crankcase (Motor mount bolt hole location) I could be wrong (and I hope so) but maybe your #1 #2 main bearings are out of spec due to crankcase distortion (its a long shot, but I'm running out of ideas, lol) What speed did you run your dremel at and what kind of compound did you use on your crankcases? Man they turned out SWEET. Regards, Doug

Oil Pressure Gauge

Oil Pressure Gauge

Old school, I've been eavesdropping.... & offer these. change in noise w/bikes attitude could be due to something shifting internally. If you havent already, remove points cover & assure there is no crankshaft end travel by referencing end of points cam both staticly, & running & changing attitude. if none, remove clutch hub & insure cl. basket nut is secure. as either worn crank center main bearing block, or a loose cl. basket nut could be the source of your' woes. while cams can shift some, I doubt they have enough mass to shift enough w/attitude to make noise... Probly worthless, but cheap to check..luck G

I disassemble engine because of that knocking. And I replaced many worn parts inside, and use propper torque on all bolts, replaced all bearings except crankshaft, all oil seals, new camchain, new starter clutch, rebuild clutch basket...In same time I examined crankshaft bearings, rods, pistons, piston pins and all of that was in excellent condition. All oil pasages were clean. There arent any signs of miss oiling.
After I assembled and start engine sound appeared again. The same knocking like before!? WTF
The only thing that I didnt do is the cylinder head. Head was arranged in machinist shop in my neighborhood. This time and 18 month ago. This is the first thing that I will now entertain with. Especially because I stetoscope the hardest knocking below left side of ex cam. I took of cams and examined shims. And I found that they adjusted valve clearance grinding shims. I examine all shims and some of them have thickness that varies on same shim. The biggest varies are on #1 ex shim (0,010mm) and on #3 ex. shim (0,017mm). I suspect that unevenly grinded shims in one moment (when engine is hot) can rotate and push cam on left side where it would bang on cam stopper under #1 cam cap. Just a conspiracy theory but will see when I put new shims in tappets what happens.

This is tehnical info of today condition in my kz900 head. Valve clearance and shim thickness. Red shims are grinded and red numbers are variations in thickness.

WTF... Intake shims 2 & 3!
That is NOT NORMAL!!!! Junk those shims now!!!

What's the Camshaft lobe tips look like?