I am getting ready to run one of my OS40cc 4s in my Cub this weekend. I will be breaking them in for my Ziroli B-25 build later this year. So fare the engine looks well made short of the throttle and choke arms, they look like toys
so I replaced them with aluminum arms. I am making my own muffler pipe and putting the stock muffler in the fuse like the canister installation. The stock setup is not user friendly, ugly as hell.
TB