I have rectangular ( but narrow) intakes on my motor and I use round cups with ho issues. Although there are two cups, only one is active (water supplied to it) Some motors larger than mine need dual feed cups to get more flow. My muffs are tight. You have to fiddle with the edges to get them positioned, they won't slide on just by pushingBumpye said:So after reading all the other posts, I decided to hook up the muffs and start the engine before launching next week (hopefully). I have a 225 Yamaha with rectangular intakes. I purchased the muffs with square cups and attempted to cover the intakes. The problem is the intakes are located on the lower end where it starts to flare out to the bottom "bulge". The cups would not fit tightly on the intakes. I started the engine anyway, and the second it started, I shut it off. Just wanted to make sure it would start anyway. Are there other muffs available? I've only seen two available in the other shops...round or square cups.