There are a number of mods you can do for the Viking, the billet replacement exhaust tip is probably the best bang for the buck, but the only drawback to it is it increases noise. If you look at some of the other Yamaha models where the muffler is perpendicular to the vehicle such as the Wolverine, you'll notice the exhaust tip is at a 45 degree angle. Why Yamaha chose to angle the exhaust tip straight down on the Viking is a mystery to me but by doing so it has 2 undesirable effects: It directs sound waves straight down, which have a greater chance at bouncing back at the cab, making exhaust noise louder. Secondly, it shoots a strong exhaust pulse to kick up dust, creating a bigger dust cloud than your tires alone would create. You can feel this with your hand if you place it at ground level under the exhaust.

To remedy this, simply cut the exhaust tip at a 45 degree angle. It takes 5 minutes with a hack saw.

Now if you place your hand where the exhaust hits the ground you'll notice there's very little pressure. You've also just decreased backpressure a little although you're not going to get whiplash. Finally the sound is directed more rearwards where it may be a little louder directly behind the vehicle, but a little quieter in the cab. Try it and let me know if you notice a difference in either reduced dust kick up, noise, or being able to hold top speed better\sooner.