Before stripping the bike down I thought that this would be straight forward however it has proved not to be.
When the bike is warm the kickstart engages every time however when it is cold it just will not engage but does sometime catch but lets go when kicked

.
My initial thought was that the serrated teeth had worn but when it was stripped all seemed OK. It was all reassembled and was OK to start with only to revert to not engaging when it was cold the next time.
The bike belongs to my friend and he is starting to tire of the teething problems he is having with an otherwise sound MK1
Thanks
Eddie

they might seem ok but they will be very slightly rounded. a short fix is to stretch the middle spring ( the one that opushes the ratchet together) this should help for a short while but not a permenant fix.
jon

Thanks Jonorow.
I swapped it over with a spare kickstart assembly I have so I'll see how that works.
I have stripped the original right down but cannot see any real wear. It is also weird that it will not grip at all when the bike is cold first thing in the morning but once warm will then work for the rest of the day without fault.

Hi Eddie , i haven't had to have the A/Rs apart, yet, but i presume the mechanism is the same as for most kick starts ,in as much as a centrifugal gear is thrown , to engage the drive gear, so , logic would dictate that some form of stiction is interrupting this process rough shaft or old oil residue built up, i think if you are not generous with oil change frequency , you can quickly accumulate pockets of detritus within areas of the casing .
It may be worth getting a lighter , and cheaper oil, to act as flushing agent , and have a short run with that oil in, the colour of the oil will dictate if it's worth repeating the process again .
Regards Mike

Fitting the spare kickstart assembly seems to have cured it but I still can't see where the original has worn.
Problem solved for now.

you'd be supprised on how little wear it take to cause a slip. I had a bike that kept sliping out of 3rd gear, took the engine apart and checked the gear against another. it was just a very slight rounding on the edge but was enough to jump out all the time.
Jon