Blackie,

I am installing an Irvine .53 in mine. My friend also has an OS .46. What's neat is both engines have the same engine mounting configuration and muffler bolt pattern as well. Consequently, we've been able to fairly compare the two engines in the same plane. Although the trusty .46 started easily, idled and transitioned well, the Irvine .53 is a true workhorse that is quite impressive. Like any other American-blooded male in search of more power without the weight penalty of a larger motor, my friend purchased a Jett muffler and I went with the Weston minipipe. The Jett picked up both motors around 1,200 rpm with a 10X6 pipe on 15% Coolpower. It is a fairly loud muffer though. We next tried the Weston minipipe and all I can say is WOW. His picked up 1,500 and mine shot up 1,800 rpm. Both of us we're wearing grins. Now, I'll say one thing. Fuel economy did suffer. Who cares? Anyhow, if you want substantial improvement with your .46 then run, don't walk to the nearest Weston supplier. I think it was about $42 if I remember right.

Thanks for taking the time to send digital photos of your plane.

Gary