Haynes, as accurate as ever!

[warren3200gt]

So I thought the top end of the z1000a1 I picked up was a little noisy and decided to investigate. Haynes says valve gap should be 0.05mm to 1.00mm, or 0.002 to 0.004 thou. Well there not the same are they!
Normal Haynes typo, so its 0.05mm to 0.1mm. After checking my gaps who ever shimmed it up must have been working to the typo dimension as all of mine bar 1 were around .30mm.
Little wonder it was noisy!
0.05mm tolerance between upper and lower limits seems awfully small when 650's are double that, any reason?

[zed1015]

The Z900 clearances were 0.05 to 0.10mm but this was later changed to 0.10 to 0.15mm due to exhaust valve burning issues when the clearance got below 0.05mm.
All the thou manuals and updated 900 manuals should state 0.10 to 0.15 .
Ideally you want to be towards the upper end of the range at 0.15mm and if using performance cams at 0.20mm.

[warren3200gt]

That makes more sense! Whats the lobe height of standard cams as I dont know what it's history is and I dont trust Haynes info

[zed1015]

All the Z9/1000 up to the mk2 ( kickstart motors) share the exact same cam timing specs and the LIFT averages around 8.06mm give or take a fraction either way due to mass production which makes no difference to performance.
The lobe heights and base circles differ between the inlet and exhaust but the lift works out the same for both.
Just measuring the height across the whole cam will not indicate the amount of lift it has.
On the later non kickstart J/GPZ motors they started to vary the cam specs slightly to suit the model type, So the J was pretty much the same cam as the earlier bikes whilst the unitracks were hairier and the Ltd's a bit softer.

[warren3200gt]

I think ive tracked down the info I need from the KHI workshop manual. According to that the overall cam height should be, inlet 36.21 - 36.39 with a limit of 36.12 and exhaust 35.71 - 35.89 with a limit of 35.62. So if Ive got those dims I am safe in assuming I have std cams? or if thats not the case how can I tell what cams I have?

[zed1015]

Using the overall cam height is ok for checking wear of the stock cams as they all have the same base circle but an aftermarket cam could have the same overall height but use a smaller base circle which would actually mean it has a higher lift.
You need to measure the overall height and subtract the base circle to find the lift and if it's close to 8mm they are probably stock.
The most common indicator of an aftermarket cam is it having the marks CWC and/or K259 cast on them as well as number/letter codes stamped or engraved near the cam sprocket flange or the end of the cam.
Most stock cams simply have L and R etc cast on them with a number 2,3 or 4 etc before the L depending on model or year and in the case of later J cams etc they sometimes also have one or two grooves on the blank part where the tacho worm is usually located to indicate the model they were intended for .

[warren3200gt]

Cheers chuck, stock cams it is then, all gaps now at .11 to .13, back together and much much quieter, well as quiet as 40 yo Z can be.
Test ride tomorrow to check for leaks.

[kev edwards]

I just checked my Haynes and mine is correct, whereas the cam cap bolt settings I had to cross out and write the lower settings in, but even that is ambiguous as according to what bolts are in there chrome plated ones will need the lower settings due to it's ability to glide on disimilar metals unlike the plain steel which grips the alloy surface better.

[warren3200gt]

What edition/publish date is yours Kev. Mines the RED manual for 900's & 1000's Combined. is yours just 1000's?

[kev edwards]

Mine is the 1015/903 with the red 1000A1 on the cover 1977 version isbn 085696 222 x. and that's not a kiss Warren it's part of the code number.

[warren3200gt]

And I thought you cared. No wonder you found it so easy to move to the flat lands.
Gone off to check mine now. Mines exactly the same manual, Haynes can't even get two copies of the same manual correct, how scary is that ?

[kev edwards]

That's the print game, we both know how it works.

[warren3200gt]

But any computant publisher would at least send out a corrections sheet or in Haynes case pamphlet.

[Big Fluff]

Ahh, the life of a technical author.
I've been writing/authoring workshop manuals for over 25 years and whilst I must agree with you regarding Haynes, I have never had anyone say "what a great manual that is", you only hear about the mistakes
After writing for Bentley Motors for the last 18 years, I can't wait to retire now. 40 years of hard labour is enough.