A four stroke muffler would be to restictive for that engine. Don't think you'd have much luck getting it mounted. You can got ot www.jtecrc.com and see different mufflers that you can use depending on how you mount the engine. (Pitts style muffler or exhaust manifolds) I.E. Upright,on its side or inverted. There are others as well. Have you asked Horizon if they make any after market mufflers to fit that engine? If not Jtec maybe can make a recommendation. Good luck and have fun.[&:]