ATC 70 question

[wpginterceptor]

I purchased an atc 70 today and was gonna change the oil on it.. I started removing the bolt on the lower half of the motor when I removed the bolt there was a flat headed screw inside which I removed as well and a long spring came out..

needless to say that wasn't the oil bolt, I since found the right oil bolt BUT what is that other bolt for? the one with the threaded screw and spring?

hope this makes sense

this threaded srew and spring was close to the shifter!

[shortline10]

Cam chain tension adjuster . Put it all back together tighten the center screw first and lock down the nut and you should be good again .