I have some past experiance long long ago tuning a traditional type tuned pipe for max RPM and performance but I have never used a mouse can type muffler untill now.

I will be running OS.25 fx and Webra Speed 25 on mouse cans for Open B combat.

It appears that the one mouse can that I currently own can be adjusted for length much like a slide trombone you might say.

Can you guys give some guidance on a good starting length, what props to use for the OS .25fx and the Webra .25 speed and what RPM's should I be trying to obtain for these engines on the groudn with reccomended props.

I have been told I will have to launch the Webra on the rich side and let it "come on " the pipe/muffler" as the plane unloads in flight. Agree, disagree. I have also been told to switch to a remotely mounted needle valve with a fairly fine thread so I can get good neelde settings.

Thanks