RE: Power Decrease Using Exhaust Deflector.
I have had a similar increase to (Ken6PPC OS46AX) on my OS55AX with the Deflector off.
I believe there is a slight increase in power now.
I had already taken the baffle out of the muffler and will continue to run it without a deflector for now.
Unfortunatley I do not have any quantifiable figures as to RPM or power increase. It just seems slightly better.
So far the OS 91 4C-
SuperTigre 51-gasoline -
Webra 55 and Jett muffler- Have slight reported gains in RPM.
OS46AX
OS55AX Slight decrease in RPM.