Find your front and rear differential. There will be a nipple on there with a small black rubber hose going up. Sometimes, they are run up a few inches and then bent over. Take this hose and run it up the the top of the bike. It is a vent tube for the differential. I ran all of mine ( 2 Carb vents, front and rear differential vents, fan vent, ect.. ) up under the headlight pod. No problems so far. The 650 Rincon is a 2003 and I just last week changed the rear diff fluid. I just turned 1990 miles on the bike and I am in the water more that out. It came out as clear as the new fluid Iput in.. Here are some pics..