hs40!

Got this today was told t was tucked away for at least 20years any ideas on what it is and maybe when made the engine is model HS40-55290B

Hey guys, went and ut the new CJ-8 in my HS40 today. How do you guys fully tighten it, i can't get a wrench or sock on it at all, its so short, it goes down to the fins on the head? Any secrets to this? Also, I ordered 2 carb gasket, a new petock and carb kit for my bike from Brandt at...