I have an OS 46 FX that the muffler nut fell off and the cone and the back end as well..... I got all the parts... and found a nut that fits the bolt but my question is this ... the baffle - cone.... which way does the point of the cone point ? Towards the exit or the entrance of the muffler ? My guess is the exit.... but who knows haha ....

The cone points toward the back or exit end of the muffler. Leave it out if you want a little more power and very little more noise. If you use it think about filing a small notch in the bottom of the edge of the baffle/cone to let the oil out that might accumulate there. Keeps it from running back into the engine or out the exhaust when your transporting your plane.
Fred

Something else you might consider is putting the two halfs of the muffler together permanently. All my two piece mufflers get put together with JB Weld epoxy. They never come apart. I just clean the mating surfaces with some alcohol then mix some JB Weld and apply at the seam. No more loose mufflers.

When reassembling remember on most of the current OS mufflers of that type the tailcone is threaded. The long bolt must be tightened while the tailcone is being held in the proper orientation of the angled tail outlet. Only then is the external nut tightened, its purpose is to serve as a jam nut aginst the tailcone threads. If the long bolt is not tightened first before the nut is tightened then this is the chief reason for the loss of the tailcone.

John