Yes. Almost certainly due to a weak spring.
Snatchy clutch or Kangaroo petrol?
- Thread starter nkt267
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Hello Rob, Now it's getting Tricky !! That's why most racers go for a Multi plate clutch. Cheers Bill.
Bill is correct but I was assuming that this was a road bike and used as such. If you are revving to over 4,000+ rpm before you change gear then that could be the problem. However, if at 4,000 rpm or below (and note that is an approximate value) then the standard clutch should free. There are braver souls than me who do not even use the clutch for changing up at high revs!!
Then get the Book out and look up Double Backlash gears for the Lightning !! Cheers Bill.
On my race bike, I ended up drilling holes in the heavy end (balance them on the pivot hole) of the shoes and adding lead to the light ends so it would shift at 7K. BTW, when I told Big Sid of this, it was news to him, but within a month he was advertising how to buy his clutch mod.... 
I learned about it from Bob Kounts, I'm sure Rollie Free told Bob about it and PCV more than likely told Rollie...
Cheers, John
I learned about it from Bob Kounts, I'm sure Rollie Free told Bob about it and PCV more than likely told Rollie...Cheers, John
I wish we had the Forum years ago !! There are lots of tips I could have used then, Cheers Bill
Wise words from Bill. Forums like this can be a great resource. If you have a problem someone somewhere in the world may have had the same problem and found a solution that you can use.
Not a frequent visitor to the forum but this thread has been fascinating. I have a couple of points to add to the search for the perfect clutch. When I was having trouble with the primary clutch not lifting squarely, I eventually tracked it down to the end of the pushrod not being square. Spinning it in a drill showed it was like a swash plate. Ground it square, and hey presto. I know it seems ridiculous that a thou ar two at a radius of 0.125" can swing the whole primary clutch over, but it did. Another thing to check is that the two clutch shoes are "symmetrical" - similar thickness of lining and, when at rest, similar clearances between linings and the drum, and similar (preferably no) clearance between the plunger pins and C14s. (In my case I fitted a sleeve round C14 to reduce backlash on one side. Then there's the old trick that I haven't seen mentioned above of fitting 6 washers behind the primary plate C21 because this plate can sometimes foul on the C9 pins behind it, limiting the rocking action of the shoes. (Look for polish marks on the back of C21.) When checking and balancing the C29 springs, also check and balance the C30 cups - I've had cups of different depths that have the same effect as different length springs, and it's the last thing you look for . . . Clearance under the C20 nut should be the minimum that leaves it free. Not only does this control end float but, if there's wear in the bushes the whole primary clutch and shoe carrier can rock relative to the drum. I could see this in my clutch- when operating the lever the primary clutch seemed to 'flop' down as it lifted, moving more at the top than the bottom. increased shimming under the nut stopped this. When you eventually get it right you will wonder what all the fuss was about . . .
Just goes to show that one can always learn something new about Vins. The mod described by mercurycrest is a totally new one to me and sounds like a really good idea. Any chance of a photo some time so that we can see just how large, and where, the holes had to be?
Hello T/T, Does this mean you are going to get some made !! They will sell like Hot Cakes !! Cheers Bill.