Using m42 lens adaptor with asahi pentax auto takumar 55mm f2.2

Thanks to APUGers, I bought a M42 lens adaptor to use on my Canon FD bodies. I originally bought it for 135mm 3.5 Takumar. I also have a asahi pentax auto takumar 55mm f2.2. The lens doesn't stop down when I turn the f stop ring. My question is can I only use it wide open with the adaptor? Any insight will be appreciated.

With the lens out of the adapter, push in the pin at the bottom. The lens should stop down. Now resist the urge to open the lens by "cocking" the silver lever since your camera and adapter don't push the pin in. Anytime you accidentally set the lens wide open, you'll have to remove it and push the pin in.

Hey Bill. I'll give it a try. So the lens should stop down and open up when I turn the f stop ring?

Thanks!
Don