I just gotta ask, why do you want to add smoke to such a simple, light, nice flying airplane. you need another tank, pump, . . . etc. Most four strokes in that range have standard sized mufflers. If you find the diameter and thread size of your magnum's exhaust pipe, then you may find a muffler to fit, for a compatible manufactures. Bisson makes many mufflers, also, Bennett and many others make mufflers that are smoke capable. Good luck in your search.