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Need confirmation that timing is set wrong on my 1976 KZ900 24 Sep 2023 09:54 #889715

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That doesn't look like the crank sprocket. It looks like a roller someone put in place of the plastic one in the middle. If so get it out of there and get the right one. 
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Need confirmation that timing is set wrong on my 1976 KZ900 24 Sep 2023 11:47 #889720

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It is the primary drive sprocket not the camchainsproket it looks like a pinbearing in the first photo i agree. The rubber wheel in the middle of camchain tunnel i have remowed before the pick was taken  it was hard as stone.Maybe the black pieces i found is from one of the "rubber" wheels ? i will not check that now because im eating a cake and watching a movie =)

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Need confirmation that timing is set wrong on my 1976 KZ900 24 Sep 2023 12:36 #889721

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Update stopped eating cake and took a closer look on the sprockets and rollers. The sprocket wheel that is in left on piicture is very wiggely and i can push the inner needle bearing out with fingers. The sprocket that is sitting on top of the camchain tensioner bar is firm but will replace it .The rubberwheels is hard as bone and the small square rubberdampers is like stones.
The top idler is total lose can wiggle it in any direction and also up and down and the rubber dampers on that is like stones too

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Need confirmation that timing is set wrong on my 1976 KZ900 24 Sep 2023 14:38 #889722

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It is time to have a requiem for them.
1982 KZ1000 LTD parts donor
1981 KZ1000 LTD awaiting resurrection
2000 ZRX1100 not ridden enough
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Need confirmation that timing is set wrong on my 1976 KZ900 25 Sep 2023 05:42 #889734

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It is time to have a requiem for them.



No im going to sell them on ebay as "good as new"  
no they go in the bin if i cant find another use for them.

 

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Last edit: by Rolf1976_KZ900.

Need confirmation that timing is set wrong on my 1976 KZ900 25 Sep 2023 05:45 #889735

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A quick look at the head
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Need confirmation that timing is set wrong on my 1976 KZ900 25 Sep 2023 06:18 #889736

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A word of warning.
DO NOT have the head skimmed for whatever reason until you have checked that the cams spin free once bolted in the head in its free state on the bench with the valves and springs removed.
If the cams bind do not skim the head.
Some of these heads have a slight twist when removed which straightens out once refitted.
If one of these heads is skimmed the twist will remain in the line bored cam journals once bolted down which will cause the cams to bind.
If this happens it is a major headache to rectify the issue with many being rendered unusable.


 
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Need confirmation that timing is set wrong on my 1976 KZ900 25 Sep 2023 06:44 #889738

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A word of warning.
DO NOT have the head skimmed for whatever reason until you have checked that the cams spin free once bolted in the head in its free state on the bench with the valves and springs removed.
If the cams bind do not skim the head.
Some of these heads have a slight twist when removed which straightens out once refitted.
If one of these heads is skimmed the twist will remain in the line bored cam journals once bolted down which will cause the cams to bind.
If this happens it is a major headache to rectify the issue with many being rendered unusable.

Thank you for informing about that  zed1015 !  I will later check how the cams spin and for runout.I have a little feeling that the intake cam is not spinning  freely.
This is why i started this tread so that someone with more expertise might correct the work !



 

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Need confirmation that timing is set wrong on my 1976 KZ900 26 Sep 2023 13:36 #889804

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A word of warning.
DO NOT have the head skimmed for whatever reason until you have checked that the cams spin free once bolted in the head in its free state on the bench with the valves and springs removed.
If the cams bind do not skim the head.
Some of these heads have a slight twist when removed which straightens out once refitted.
If one of these heads is skimmed the twist will remain in the line bored cam journals once bolted down which will cause the cams to bind.
If this happens it is a major headache to rectify the issue with many being rendered unusable.

 

I don't know enough about how heads are machined, but if this is true for the KZ1000, wouldn't this be a problem with any cylinder head with cast-in cam journals?

I'm assuming that during original manufacturing, the combustion surface of the casting is machined flat.  Then the head could be bolted to a mill table using this freshly cut surface and the cam journals line honed.  At that point, any time in the future when the head is bolted to a flat surface the journals would be in line, even if the casting were warped initially or developed a twist. 

But given that the only true reference for the cam journals is the combustion surface, how does one ever skim the combustion surface?  I always assumed that there was a third surface on the top side of the head, which is cut to match the same plane as combustion surface and the cam journals. 

Isn't this surface used to bolt the head down when it is skimmed? 
Why wouldn't bolting this surface to a mill table remove any twist in the casting?
What is unique about the KZ head that makes it subject to this issue?
 
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Need confirmation that timing is set wrong on my 1976 KZ900 26 Sep 2023 15:02 #889808

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Isn't this surface used to bolt the head down when it is skimmed? 
Why wouldn't bolting this surface to a mill table remove any twist in the casting?
What is unique about the KZ head that makes it subject to this issue?





 
Yes! Any head with integral cast in and machined cam journals could be prone to this issue.
From new the cam cover gasket surface ( which is also the same machined surface for the cam caps) is parallel to the head gasket surface and it is this surface which would be on the table when setting up for a cut.
If the head is straight and the cams spin free there is no problem skimming the head but if twisted or warped beyond service limits the force supplied by general fixtures or milling clamps comes nowhere near close to the pressure of the twelve x 10mm head nuts torqued to the recommended 29 ft/lbs for stock studs that is required to pull the head straight when bolted on the motor and there's nowhere on the head to get that sort of clamping force and still have clear access to the head gasket surface for skimming.
It's possible that a fixture consisting of a substantially rigid and accurately ground plate which attaches to the head using counter sunk bolts on all 36 camcover, cam cap and top idler bolt holes may have enough spread of force to pull the head straight that way allowing it to be skimmed and maintain cam journal alignment when back on the engine but i don't know of anyone whose tried it.




 
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Need confirmation that timing is set wrong on my 1976 KZ900 27 Sep 2023 10:17 #889833

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Yesterday  started to test the valves before i start clean off the carbon just to see if  they leak.
Tested by placing the head so the exhaustports face upward and then fill the ports with solvent an let it sit
for a while.After that i tested the intake valves the same way. I found this method is very good to see if the
valves leak. I have earlier tested by filling the combustion cambers with solvent ,but then will have to wait
for long time to see if a valve leaks and then the fluid evaporate =) if its not a major leak.
The valves was very good only nr 4 intake had a small leak and some had a little sveating, but that is good after 40 minutes of standing filled with solvent. I will next take them out and just check if the valve seat and valve face width is in spec.if not i will cut the seats.Also will check the valvestem for runout and if the valveguide is in spec.

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Need confirmation that timing is set wrong on my 1976 KZ900 02 Oct 2023 08:14 #889993

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.since last time i have done some more work on the head. Measured the head for warp and it was not warped .Cleaned valves and measured them for runout and  valvestem thickness.
also done the wobbletest that i dont think is so acurate.The valves look very god and i dont think it is too long since someone refreshed them.The valveface width looks good i have not measured that yet,but no serius pitting .Maybe it is enough just to lap them .Today i have measured the camchafts for runout and also the
oilclearance on the journals with plastigauge. all is in spec so that is good.Next is to measure the springs
and lap valves

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