Bouncy speedo question

[Davelu88]

Hi All
         Can anyone answer why my speedo on my 400/4 goes a bit wild, it seems ok up to about 60ish but after that goes bouncy even up to 120 mph !!!
Cheers

[Nurse Julie]

Pretty standard on a 40 year old bike me thinks. I think it's got something to do with damping and oil or something like that. Peter Horton (Kent400 on the forum) overhauled mine and I know he does a lot of forum members clocks, great job he did too.

[kent400]

Thanks Julie, I would suggest checking the cable first. Draw the inner cable out clean and re-lubricate it. That were to start, if the cable is good and revolves freely there could be a problem with the gauge.

[Davelu88]

Many thanks for replies, it dont worry me that much but was just wondering why, I will keep you in mind Peter if i decide to get them done .

[petermigreen]

Mine's the same. After around 60 it bounces up and down. I just go slowly 

[Davelu88]

I may have to slow down !!

[Green1]

I don't mind my speedo bouncing up and down but when I enter a corner and it sticks at 120 plus it makes you think twice.
It really puts me off at times.

[Davelu88]

For a split second i actually thought mine was really a Super sport when my speedo said 120mph 

[ogri211]

I think the problem is when people remove the clocks from their bikes they store them upside down and the damping fluid runs out of the damper, this is also evident on some old clocks that the faces are stained with the fluid when they have been stored for a long time upside down.