Kick start not fully returning

Hi All,

After having kicked, I have to help the kick to return to its "rest" position because the spring seems to be not strong enough.

It was OK when I tried with the gearbox off the bike, and when I kicked for dozens of times to prime the oil pump (after the engine rebuild). So I think that the spring and the kick shaft are OK.

The problem started after the engine had run for a few seconds. It looks like something in the gearbox ( a shaft? ) has moved and creates now a friction which is the cause of the problem.

The gearbox is a 1960 model (coming from a Dominator) and apart from that, everything else (eg:gear change) is OK.

Many thanks for your thoughts.

Laurent

Isn't this usually related to a bush moving out of 1st gear ?
(And assuming you have a good bearing on the layshaft.)

BTW, in the dommie manuals back then, there were 2 sets of instructions for installing new bushes in the gearbox.
One for the solid bronze type bushes, and another set for the sintered bronze type bushes.
They had different requirements for being fitted up so they stayed there, and had suitable clearances.
hth

Hi, The 1960 Dominator gearbox has a weaker/smaller return spring.
Norton only started using the modified box in 1964.
Two years later than Matchless/AJS.
In addition the Commando kickstart lever is a lot heavier and to complicate things further the weight of it is on the left side of the shaft which doesn't help.
In this case I would use the Dominator Kickstart lever as in the older boxes the TS layshaft bearing is wider and thus stronger.
On the other hand you may have a problem with a bent layshaft or a sticking kickstart shaft bronze bush.

In stead of layshaft bearing being wider I meant kickstart shaft bearing.(the layshaft bearing being inside of the kickstart shaft)

Thanks for your comments Gents.

I don't think it's related to the spring neither to the weight of the kick lever (a RGM model) nor to the kick shaft as it worked perfectly when the gearbox was off the frame.

I took it off the frame to cure the problem which appeared a long time ago. Then I noticed that the splined part of the kick was rubbing slightly against the gearbox outer case. I took the kick off to grind it a bit, put it back in place and made a test : OK.

As explained in my 1st post, the problem re-appeared after that engine had run for a short time, as if the primary (belt) drive had re-created it.

Has the kick shaft to be shimmed to adjust its axial play?

Merci,

Laurent

laurentdom said:

Thanks for your comments Gents.


I took it off the frame to cure the problem which appeared a long time ago. Then I noticed that the splined part of the kick was rubbing slightly against the gearbox outer case. I took the kick off to grind it a bit, put it back in place and made a test : OK.

Has the kick shaft to be shimmed to adjust its axial play?

Merci,

Laurent

Click to expand...

Hi,

If it was me I would have it to bits to see why it's rubbing. It depends what type of layshaft bearing has been fitted wheather it needs shimmed or not, but by the sound of things that is uncertain. Best of luck.

Jg

Oh by the way ,I like your machine, very tidy.

Please at least pull the covers off, check and /or replace the layshaft bearing.
This condition (kickstart not fully returning) is exactly the symptom which revealed that my bearing had failed.
Riding the bike in such a state is dangerous for your gearbox, not to mention your own safety. The shaft could grab, spinning the kickshaft arm forward, and take out your ankle.. Or it could lock up the box and the rear wheel with it.
I got lucky, having a friend (Steve Payne, RIP) who recognized the problem, and helped me replace it before any other damage was done.