C: Clutch Twin Clutch Drag

sharkey

Forum User
VOC Member
When operating the kickstart lever with engine stopped and the clutch pulled in there is no clutch drag but when operating the clutch having already applied pressure to the k/s lever there is some drag. C23 is not lifting absolutely square but has a minimum clearance of 25 rising to 40 thou' around the plates. All springs relatively new, are of equal length and free to move within their cups.
There is at least 25 thou' clearance between the clutch shoes and drum; plungers C11/1 are free and butting against the correct C14 pins but those pins have C16 sleeves besides the 3 in the normal C13 locations. The plunger springs are exerting reasonable pressure.
There is approx 10 thou' clearance at C19 shim.
I would appreciate thoughts on the cause of the drag and how it might be eliminated?
 

vibrac

Well Known and Active Forum User
VOC Member
To be clear the drag occurs when you move the kickstart before you operate the clutch but not when you operate the clutch before moving the kickstarter
Perhaps 'operating the kickstarter' needs to be clarified (for me) with clutch in are we just applying pressure or actually moving it? and with it out what are you applying just pressure or moving it?
 

sharkey

Forum User
VOC Member
Your first sentence is correct. The k/s is moved through its full travel for both situations. I lifted the clutch before moving the k/s because it seemed to me that this would show the pilot plate lift was adequate for drag-free operation of the pilot clutch.
 

vibrac

Well Known and Active Forum User
VOC Member
I cannot see how the change is caused
I surmise the difference is between lifting the plates when stationary and lifting the plates in motion. But how that changes things I cant see, its not as if the plate is "peeled off" as per Velocette.
at the other end I doubt the operating of the ratchet or the rotation of the shaft affects the movement of the pushrod
beats me
 

john998

Well Known and Active Forum User
VOC Member
Hello, this is a problem that has plagued me over the years. After loading the clutch it won't clear. It is usually caused by weak plunger springs and or the plungers being too short due to worn shoe linings and general wear in the mechanism.
I have placed a thread on the forum recently about this. John.
 

MarBl

Well Known and Active Forum User
VOC Member
Maybe its the common C5/1 fouling C21 problem? My clutch suffered from it too and if the setup has already been used it should be easy to identify via corresponding marks on the back of C21.
There were no issues on standstill but substantial dragging on the road.
Maybe your preload on the kickstarter has a similar effect on "connecting" the C5/1 to C21, especially if there are already some deeper marks to give the C5/1 some grab? Just guessing
 

sharkey

Forum User
VOC Member
@MarBl - A C5/1 did slacken recently, possibly coincidental with a broken tang on spring C45 that caused loss of clutch function. There are marks (a gouge really) on C21 which I took to be from that event only but which may have a longer gestation. I will take the clutch apart again.
@john998 - I had gone through your "centralising plunger" thread which I found helpful.
@Bill Thomas - Aren't we all? My next enquiry is the play between C17 bush and C20 which may be excessive. Is there a published fit for that?
 

greg brillus

Well Known and Active Forum User
VOC Member
It can be a mistake to make many of the clutch parts too snug a fit.......The C 13 assembly needs to rotate back and forth easily with no binding........not enough end float on the C17 bush and the C20 nut can be an issue, especially if there is sealant caught between the two........One other possibility is running the primary chain tension too tight, this pulls too much on the chain wheel, thus making the whole assembly spin like a swash plate.
 
Top