Tach Drive Alignment


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shiskowd
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Tach Drive Alignment

Post by shiskowd »

I've noticed a slight squeak at times coming from the tach cable on my newly restored Z. New drive cable (lubricated), new seals in the tach drive. I believe I've found the issue - the tack drive isn't centered perfectly in hole in the valve cover. The misalignment is causing the tach drive shaft/cable to rub on the drive cap - it takes a bit of pressure downward to get the cap to slide over the tach drive. The most obvious cause of this would be the valve cover gasket being too thick, positioning the cover higher and not aligning with the tach drive in the cam bearing cap. The gasket is not OEM, I replaced the original with the one in a 'value' Foritti gasket kit. New bolt seals for the valve cover, the bolts seated solid in the cam bearing covers. No oil leaks on the valve cover anywhere. Unless the valve cover is warped it has to be the gasket thickness.

Any ideas?!
2022 KTM 890R, 1982 Pro-Link, 1979 CBX 'Z, 1975 Moto Guzzi 850T
Long Sleeping '79 CBX Restoration > viewtopic.php?f=102&t=11699

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shiskowd
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Re: Tach Drive Alignment

Post by shiskowd »

Bumping and more info...

Thinking the aftermarket valve cover gasket was the issue causing the misalignment, I cleaned up the old OEM gasket which was in fine shape, the rubber softer and slightly thinner than the aftermarket. The resulting tach drive alignment was better but still not perfect. I ran it like this for a time but the tip of the tack drive broke off after a few short rides.

Below is the picture of the tach drive with the trust washer slipped on showing that it's not centered in the valve cover openning.

I can't imagine the #6 camshaft cap is the issue, it has to be the valve cover. Any ideas?!

Image
2022 KTM 890R, 1982 Pro-Link, 1979 CBX 'Z, 1975 Moto Guzzi 850T
Long Sleeping '79 CBX Restoration > viewtopic.php?f=102&t=11699

CBX-tras
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Re: Tach Drive Alignment

Post by CBX-tras »

Are you using allen head cap screws for the cam caps instead of the stock, hex head bolts?

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shiskowd
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Re: Tach Drive Alignment

Post by shiskowd »

...yes, using cap screws :? I recall someone (maybe you) mentioning to be cautious about the clearance using cap screws. Mystery solved... :-)

While I'm in there replacing these, what is the proper method to retorque the heads? Back all the nuts off partially (or completely) in the sequence in the manual and then retorque per the sequence in the manual? Or, can you back them off individually and retorque individually?
2022 KTM 890R, 1982 Pro-Link, 1979 CBX 'Z, 1975 Moto Guzzi 850T
Long Sleeping '79 CBX Restoration > viewtopic.php?f=102&t=11699

CBX-tras
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Posts: 386
Joined: Tue Feb 16, 2010 1:29 pm
Location: Clinton Twp, Michigan
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Re: Tach Drive Alignment

Post by CBX-tras »

shiskowd wrote:
Mon Nov 01, 2021 10:19 am
...yes, using cap screws :? I recall someone (maybe you) mentioning to be cautious about the clearance using cap screws. Mystery solved... :-)

While I'm in there replacing these, what is the proper method to retorque the heads? Back all the nuts off partially (or completely) in the sequence in the manual and then retorque per the sequence in the manual? Or, can you back them off individually and retorque individually?
Here's that photo again of where to clearance the inner valve cover if anyone is using ALLEN HEAD CAP SCREWS for the cam caps.

Retorquing: I just recheck in sequence without disturbing anything.
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