Got a stupid question. I've got the giant UCanDo and the engine is mounted inverted with a nice cowling to cover it. I notice on all the pictures they show a nice opening for the muffler to come out and no holes on the other side except the needle adjustment. How can you put the muffler on without a couple of holes on the other side of the cowl to get your allen key into to tighten the bolts. I'm using the standard muffler with the OS 160. Must be a accessory (there always is in this hobby) that I need to make this work. Thanks, Jerry.