wow that sucks! I wonder if this is a result of the tank being pressurized and then warping from it over time?? On the bright side you shouldn't have any trouble getting it warrantied.Not the usual fit and finish you would expect from ski-doo. All jokes aside it collects a lot of pine needles/tree branches keeps pushing tank up. Always garaged & trailered in enclosed trailer. Maybe skidoo will perform another bandaid fix haha.
Wouldn't the air vent be designed to allow more than enough air through while running at WOT? Pressure in the tank wouldn't affect HP + or - unless the vent is plugged. pressure from the injectors is what it is you can't turne up you injector pressure with Tank pressure unless you get a computer programmer. I thought the 800R injectors where pretty much maxed out. Maybe the 850 injectors aren't ? I think the vent works fine while running just sucks at venting while on the trailer up to the mountain or sitting on the hill during the day. That's how I thought it worked could be wrong I'm just a hydro physicist. Currently working on converting this beer into pure p*ss:beer; has the cut on vent rubber helped? Does BRP make a vented cap for the 850 like on the race sleds? I have been leaving the cap loos on my 850 to keep the tank from bulging up so far it kinda helps.why not eliminate the valve . i cut mine to away have zero pressure in the thank . i just cut the little rober valve so air can come in out . i did that because the gas pump and gas pressure regulator is in the tank . if air pressure increase buy one psi , gas pressure raise buy one psi also . not sure if it holding 1-2-3 psi or vacuum ?? psi but i know it have a big effect on gas pressure and engine performance variation .
i did play with gas pressure regulator and a wide-band to tune ported engine .
Apparently they don't have a vent hose down to one footwell, then back up to the bars, and back down to the other footwell anymore?This pressurized gas tank is nothing new with ski doo. I had a 2005 rev 800 and did the same thing. Point down hill gas runs out tube. Ride a bit and stop on a level surface and releas the gas cap and massive back pressure. Ski doo used a ****ty vent/ valve system. Pulled the valves out and re routed the vent lines. No more problems. This continued clear up through the last 2010 ski doo I had