Kickstart return spring

The spring changed on the AMC box  and also the inner cover and shaft so they are not easily interchangeable.I had a similar problem on my 60 box and found that when I reduced the slop in the bush the kickstart stopped misbehaving.

Hi George - The kickstart spring on the later AMC gearbox (AMC2) is one whole coil longer and stronger than the earlier box.  Because of that the locator hole in the kickstart shaft is about 0.25 inches further out.  If you do manage to fit the longer spring onto the early shaft it is coil bound immediately you start to turn it. If your gearbox has a prefix N it will more that likely have the short spring and the inner case with the hole to suit.  It also has the AMC1 ratios.  If its prefix is NA it is likely to be AMC2 with the longer spring and the peg in the inner case for the spring.  All Commandos and Mercurys have the long spring.  Cheers, Howard

As it is 1955 dies your bike have the Laydown gearbox?  I've never compared the spring to the ones used in the AMC box.

I've replaced the spring in a Laydown box and you only need to remove the plated cover behind the kickstart lever to get to the spring.  Once the cover has been prized off the spring is easily removed.  The new one then needs tensioning by clipping one end into the hole in the kickstart splines and then  pulling the other end to clip into one of 4 slots by the gearbox outer cover.  This tensioning can be a bit tricky, so have some plasters ready!

Phil.

Its easy to put the rachet in upside down and it can work for a while . If you take it appart ,something to check.

It is very possible that the spring has just got a little weak, and you can increase the spring tension

The spring cover is accessible without dismantling the gearbox.  Remove the kick start lever.  The spring cover is now accessible.  you will need to use a knife or similar to ease the steel cover off the shaft. Patience, and lots of penetrating oil may be needed.  When you get it off, the spring will be exposed.  With some effort, you can move the spring tang round another notch on the housing. 

Paul