Richard's ZR750C1 Restoration Project

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Re: Richard's ZR750C1 Restoration Project

Postby Freddy » 10 Oct 2017, 05:59

Richard wrote:
It will come up later I guess but I can tell you that the clutch is still slipping, maybe a bit less but still very noticeable. Later models, I seem to remember from the model D1 and onwards are using 2 thicker clutch plates. I guess I have to order those as well at a later date...

To be continued


What's the part number of the EBC springs you used? The ones to use in a D1 are CSK117 (these are not the ones recommended by EBC for a D1, or at least what there were recommending). A guy on the ZR7 forum (which uses the same clutch as a D1) should be given correct for identifying the ones to use.

Unless you can find a difference in the clutch between a C and D model other than the 2 different plate thicknesses (I can't see any other difference), then I'd be using the CSK117 springs. Even with the 2 thicker clutch plates, the clutch on a D1 with stock springs will still slip in the upper rev range if you use synthetic oil.
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 10 Oct 2017, 18:02

Just checked the order and I got type CSK010 which should be the heavy duty type for my Zephyr...
I'll investigate further and will let you know

About the oil , I'm using half-synthetic

Thx!
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 10 Oct 2017, 20:47

So I did a comparison using the OEM partnumbers and the ones from EBC. I wonder what difference these CSK117 have, longer or stronger? The OEM partnumbers are the same for C5-D1 and ZR7 (picture incorrectly says Z7)

Image

Freddy wrote:A guy on the ZR7 forum (which uses the same clutch as a D1) should be given correct for identifying the ones to use.

Can you please share the URL to this article Freddy? There are over 100 pages with topics and I can't search as I'm not registered... :roll:
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Re: Richard's ZR750C1 Restoration Project

Postby Freddy » 11 Oct 2017, 00:14

Richard wrote:So I did a comparison using the OEM partnumbers and the ones from EBC. I wonder what difference these CSK117 have, longer or stronger? The OEM partnumbers are the same for C5-D1 and ZR7 (picture incorrectly says Z7)

Image

Freddy wrote:A guy on the ZR7 forum (which uses the same clutch as a D1) should be given correct for identifying the ones to use.

Can you please share the URL to this article Freddy? There are over 100 pages with topics and I can't search as I'm not registered... :roll:


Your spreadsheet highlights the issue. The C1 to the ZR7 are all the same motor and same key clutch parts. But Kawasaki and EBC have identified a need to progressively beef up the clutch. Why? Because its prone to slipping, especially when synthetic oils are used which arrived on the scene in the mid 90's onward.

Why would anyone use a CSK038 set of springs in a D1, but uses a CSK117 set in the same identical clutch just because the near identical motor sits in a ZR7 frame? The answer is someone with a ZR7 identified that the 'heavy duty' EBC springs being sold for a ZR7 were no heavier that the genuine OEM springs. They were longer, but used a slightly thinner gauge wire, so the net effect was near identical. He worked with EBC on the issue and they came up with the CSK117 as the set to do the job. So it looks like they updated their records for a ZR7 but not the Zephyr models.
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 11 Oct 2017, 18:26

Now I'm convinced Freddy ;)
So I'll order CSK117 instead then.
Still love to see that URL though.
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Re: Richard's ZR750C1 Restoration Project

Postby Freddy » 12 Oct 2017, 00:22

Richard wrote:Now I'm convinced Freddy ;)
So I'll order CSK117 instead then.
Still love to see that URL though.


http://www.riderforums.com/zr-7-maintenance/75324-ebc-clutch-springs.html
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 12 Oct 2017, 10:16

Thanks for sharing Freddy!
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 13 Oct 2017, 21:16

Continuing July 2017

My delayed shims order finally arrived and as everything was prepared and waiting I installed them according to my calculations expecting all to be good. Well not, I first had to learn a few lessons again...

As mentioned earlier I did put some markings on the cam chain and sprockets when it was at TDC to prevent timing issues after reinstalling the camshafts. I managed to install it back with the markers aligned, it went much easier than expected. Next was to measure the valve clearances again and there it went wrong as I forgot to install the cam chain tensioner and when I rotated the crankshaft with a wrench the chain jumped a few teeth so I had to redo the alignement but wasn't able to get my markers aligned anymore.

So I installed the chain tensioner again following the documented procedure and started the counting-pins-procedure to get the timing right. As Stu and Freddy debated elsewhere on this forum I too had the issue getting it exactly as shown in the Haynes manual. At the end I couldn't get it any better and I took the decision that the manual was incorrect which was confirmed by their remarks.

Anyway with everything in place I started measuring the clearances again only to find they were all still way off. I was about to learn an important step again... As I couldn't explain my measurements I started all over again and measured those new shims expecting to have made an error. But no, all were of the correct size and location which became very frustrating. I left it for a few days during which I did some reading on The Net and stumbled across an article mentioning you have to turn the engine over (by hand) several times to allow everything to settle.

So back to the garage again where I started measuring the clearances, turning the crankshaft while doing and re-measured all of them again while rotating the crank in-between and found the clearances to become better after two full measurements. So I then turned the crank maybe ten times or more, measured again and finally they were all within spec! Anyway, like I mentioned earlier I had a learning experience, again ;)

Next I rebuild everything back to its origin place, using a brand new OEM gasket but without any liquid gasket. I only used some when installing the rubber camshaft plugs and also on the upper chain guide as it kept falling out of the head cover. I'm happy to share that until today (few months later) there's still no sign of oil leakage around the cover. Finally after filling it up with oil I hit the start button and lo-and-behold it started right away, doh!

The last adjustment to do was syncing my carbs which I succeeded in without any issue. And then all I had to do was rebuilding the bike to its final state finally able to mount the bike again to take it for a spin around the garage block. The difference was huge and over the next days I started the engine a few times after it cooled down while checking the temperature of the down pipes so I can now share that all my cilinders are firing at once when starting.

This brings me to the end of my work done in July.

Pictures still to be done though...
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 22 Jan 2018, 21:42

Better late than never here are some of the missing pictures taken during my activities last year

The old bearings from the rear wheel:
Image

The rebuild rear wheel:
Image

Cleaned rocker cover:
Image

Polished left panel
Image

Rebuilding rocker area
Image

Installing new gasget
Image

Applying loctite
Image
Image

Top cover reinstalled
Image

Alternative petrol tank ;)
Image

Synching carbs
Image
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Re: Richard's ZR750C1 Restoration Project

Postby Richard » 23 Jan 2018, 09:40

Added the last few pictures above. Now waiting for some decent temperatures...
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