Tappet clearances with head on bench

[steve452]

In his 2018 book "How to Restore Kawasaki Z1, Z/KZ900 & Z/KZ1000" the author, Chris Rooke, comments that he'd wished he'd checked the valve clearances by temporarily fitting the cams onto the head and doing the measurements with the head on the workbench. Apart from making sure that the bushings are kept oiled during the process can anyone see a major problem with doing the clearances this way? I have not yet re-installed the head on my Z1-B rebuild so this seems a much easier method than doing it installed in the frame. I'll be using the Z-Power replica of the original valve lifter tool and rotating the cams by hand. Also, does anyone know the difference between the two special tools "Valve lifter holder" 57001-109 & 57001-113? The 109 is the tool listed in the July 15 1974 Rev. 3 version of the genuine Z series WS manual, but 113 is the part listed by Z-Power that their pattern replaces. I've looked at images of both but can't see any obvious difference.

[zed1015]

You can bench shim to get them close but once bolted down on the motor and everything is torqued up they usually change but at least you know what shims are in and what size to swap if needed.
Just be sure to have the head elevated off the bench or you risk bending a valve.

[steve452]

Many thanks young sir! Also for the advice re raising the head, which hadn't occurred to me, Doh!

[z1bman]

set the clearances closer to the maximum rather than the minimum

[CAT3]

The other thing you might find, never done it this way myself, is that the cams may not remain in some positions without being locked in place some how, because the valve springs will try to push the lobes of the valves not being measured.

[steve452]

Didn't think of that! May just bite the bullet and reinstall the head and work from scratch. At least I'll still know which shims are in which buckets from the start. Thanks for your help and thanks to all the guys who replied. Much appreciated.

[DogsbolloxofZ1B]

Only put one cam in at a time..

[Pigford]

Only put one cam in at a time..

That won't make any difference

[CAT3]

It will if, for example an inlet valve is open & he turns the exhaust camshaft. It's possible to open an exhaust valve onto an open inlet valve, or vice versa.

[Pigford]

It will if, for example an inlet valve is open & he turns the exhaust camshaft. It's possible to open an exhaust valve onto an open inlet valve, or vice versa.

True - I was thinking about getting each fully closed and the force of a different valve sometimes try's to move the cam if only half closed/open.

[steve452]

In the end I didn't manage on the bench. I tried with the inlet cam and tightened the cap bolts down to a good hand tight with a socket and T-bar with assembly lube on the bushes, but could I turn the cam by hand? The feck I could. On the positive side, at least I know the head threads are clean.

[Mr Bump]

You need to wrap an old timing chain around the cam sprocket, then clamp a pair of mole grips to it. It's then quite easy to turn the cam while minimizing the risk of damaging anything.

Olly

[steve452]

Thanks for the advice but I did the clearances in the head in the end. After juggling them around found I only needed two additional shims in the end. Have ordered from Z-Power, along with a bossed front sprocket for the 630 chain as I couldn't be arsed to piss about with spacers in the end.

Many thanks to all for your valuable advice. I'll post some pics of the progress when the IT issues are sorted.

BTW which is the appropriate Forum heading to post pics of a rebuild in progress?

[zed1015]

BTW which is the appropriate Forum heading to post pics of a rebuild in progress?

Post it in Projects.