rjohnson

I have a Pitts muffler for an OS 61FX that fits the OS 91FX. Can this muffler be used on the 91FX?

jrf

My Feedback: (551)

No. It will rob power and cause the engine to overheat. Look at the difference between the stock mufflers on the 61 and the 91. A pitts for the 91 needs to be larger also.

Jim

TimC

A few months ago I decided to pull the .61FX out of my P-40 and install a .91FX. The Pitts muffler was a custom fit a it would have been a chore to use one designed for the .91. I tried it with the .61 Pitts and actually pick up some rpm over what the engine would turn with the .91 Pitts. I'd say give it a try and see what happens.