I have a mousse can muffler on a OS 46 fx. The header length is 6 1/2" . Should some of this header length be trimmed off to get the cannister to run properly ? I've tuned other header pipes by doing this to get maximum rpms. Is this process necessary with the mousse can muffler. If it is, has anyone else done this with this particular muffler and how much did you have to cut off to get the engine to run properly ?

Presently 4-5" of the header pipe is in the cannister.

Thanks

Cary