i have a 2000 zxi 1100, after 5 min of riding, jet ski bogs down, gets worse as i ride a little, more, take it to shore. shut off, open gas cap, pressure releases, and jetski runs fine for another 5 min before bogging again, question is, is the some kind of valve that is suppose to vent the tank to let air in when the gas level is getting lower? seems like the tank may be building to much negative pressure and when it gets to a certain point, the carbs cant fight the pressure in the tank so the fuel is drawn back to the tank instead of going to the carbs. is this possible? thats for any help.

 

Yes it is, I took the smog junk off of my bike which included plugging some lines that went into the tank. When I went for a test ride the bike started bogging and then died after a short time. I opened the tank cap it sucked in some air then I tried again with the same result. I figured out one of the lines I plugged was the fuel tank vent line.

The jet ski I used to have had a vent but I'm not sure where it was. Its probily not at the cap because it would suck in water, I'd examine the tank and trace all the lines to see where they go. It could just be a kinked line thats the vent for the tank.