I have a 2007 700 efi and I have a gravely noise coming from somewhere up front. It happens when I am running along around 30- 45 mph. When I speed up it goes away. At first I thought detonation, but I run 91 octane boat gas. Any ideas???

 

First thing I would do is to check the cv joints and boots for any damage,then change the front differential fluid. Use Polaris Demand Drive hub fluid only. If this doesn't help,noise could be from either the roll cage area or the input shaft if you narrow it down to the differential. Noise could even be clutch related. You just have to eliminate one thing at a time.

 

Clutch is completely cleaned and tight new belt. I read something on here about the transmission plug getting gouged by a chain??? It sounds like gravel in a mixer

 

You said noise came from up front? Yes there has been instances of chains in transmissions grinding on drain plugs.