81 YZ80 Kick Start Problems Install

Greetings to all. Newbie to the site. I have experience with British classic bikes but I have none with Yamaha and certainly not with motocross.I have a 1981 YZ80 I am trying to get going for my grandson..I have some manuals on order but while I was waiting I was wondering if anyone could enlighten me how to re-install the kick start mechanism.(It came out while checking clutch plates)The bent circular pin on the ratchet gear goes in the slot but how do I pre-load the spring.?? Where does the end of the spring go in to hold it for pre-load??. Thanks for any replies...