Today Sean and I installed the exhaust pipes and muffler assembly. This is definitely a two-person job. The exhaust pipes are loosely installed to the heads to allow adjustment to get all four pipes and the muffler unit to align correctly. The manual is pretty sparse on instructions or guidance saying only to assemble the system per the parts manual, which is only an "exploded view" diagram.
As mentioned, we loosely installed the 4 pipes, held the muffler unit in place, wiggled the pipes and the muffler unit until all the pipes lined up with the appropriate ports in the muffler, then installed the muffler springs. Installing the springs is an adventure, particularly the two inboard-rear springs. Somewhere I had read a tip suggesting using heavy line looped around the spring ends to pull the springs into place. We used boot laces with a wooden handle to do just that. Once all the springs were in place we wiggled and moved the entire assembly around until everything appeared to be well seated. The unit became fairly solid with this technique. Once all was in place we tightened the manifold bolts per the Rotax assembly manual.
We also used red high=temp RTV to "fill" the stretched and in-place springs. The RTV acts to dampen vibration which can damage the hot springs over time.
