A pic of my OS 108 muffler. Since I am using a smaller than most engines I have seen here, I need the extra weight to CG this model. So....

After measuring the volume in a OS 108 type muffler, I configured an exhaust system to provide for a similar volume to avoid limiting the engines performance. Maybe even better flow. The engine is rated at 3 hp. It has flown the Platt 79" span 109 @20lbs very well.

It also allow me more access to the fuel tank connections, and I had the aluminum laying around any how. And around $8.00 worth of aluminum and some alone time.

Steve