The main reason is there is no real good way to affix the standoff mount to the fuselage and the pipe moves around all the time. Afraid I'm gonna lose it in flight. Without the standoff mount the only thing holding it on is the spring around the head.
It is a typical OS engine. It runs great and transitions fine(IF the lo and hi mixtures are set right). BTW, it doesn't have the OS muffler on it. It has a wrap around Pitts style muffler and I'm including a mount for it too.
With the engine mounted on its' side the muffler exits out the bottom and it works great.
Damn, I got this post all crossed up with another one. I didn't realize until just now that this thread was about my Rossi Pipe and not the OS 160. DUH!
I would sell the 160 but I had rather trade it for smaller 4ST engines. Say, like an OS 70 or Saito 72.
The muffler on the 160 is a BCM Bisson Custom Muffler. Has a pressure tap and has been on the engine since I got it. I have put very little time on the engine but I know it runs just fine. I just don't have anything to put it in.
To straighten out my screw up, let me try to post properly.
The GMS 47 that I had the pipe on ran great. It actually had better transition than with the stock muffler. Response was fine. It would spool up right now with no hesitation.