Author Topic: Clutch issues- advice needed  (Read 309 times)

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Offline isettaman

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Clutch issues- advice needed
« on: 20 Oct 2020 at 09:10 »
Hi All
Having completed the build of my 80 Plus, I took it for a shake-down run only to find problems with the clutch. Firstly, the biting point was high but as I rode, the clutch started to drag. Taking the friction plate off, I found that the friction material extended over the outside edge of the plate and, consequently, was rubbing on the surrounding pins, you can see the marks on the pins. Looking at the spigot, have I got it in the correct orientation as I read about “free play” but there doesn’t appear to be any as there’s always the resistance of the return springs. Am I missing something?
Dave







Image orientation corrected - Dave, Admin - 21 Oct 2020
« Last Edit: 20 Oct 2020 at 19:42 by Dave »

Offline eddie

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Re: Clutch issues- advice needed
« Reply #1 on: 20 Oct 2020 at 10:40 »
Dave,
   As you mention the friction material (instead of corks), I presume you have fitted a clutch plate from a 'Mark' series machine. If this is the case, each clutch lining should be 6¾" O.D. x 4¾" I.D. x 1/8" thick - so should not rub against the guide bushes.
  Having refurbished the clutch, you will probably need to make some adjustments. The clutch release mechanism has 3 light springs (as seen in your second photo) that return the lever to it's rest position. (don't confuse this with the pressure of the main clutch springs!). With the clutch/flywheel nipped up on the crankshaft taper, you should be able to lift the operating arm about 1/4" before encountering the resistance of the main clutch springs. If you haven't got that free movement, you will need to adjust the position of the operating lever (by loosening the bolt and swinging the lever to the required position so that it is only the light springs that are holding it against the inside of the bellhousing). Having established that you can get the required mechanical clearance, the crankshaft nut can now be fully tightened. You will now need to re-adjust the length of the clutch cable - hopefully via the cable adjuster in the adaptor in the bellhousing, or in extreme cases, by shortening the inner cable.
   It is important that the clutch is adjusted in this sequence to obtain the correct running clearances, otherwise the release bearing will be under load at all times and will fail prematurely. The lack of clearance will also mean the clutch will be prone to slippng, creating extra heat and damage.

   Hope this helps,
                             Regards,
                                            Eddie.

Offline isettaman

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Re: Clutch issues- advice needed
« Reply #2 on: 20 Oct 2020 at 12:44 »
Thanks Eddie
That’s most useful. The friction material came from the club spares so I suppose should have been okay but I’ve trimmed it back now.