Primer bulb issue

[Yamaha3535]

Hows it going. I went out fishing last night and when I was running the boat slow I had no issue but as I went up in rpm about within a minute or two the primer bulb would be sucked in( bulb would be in the position as if someone squeezed it) and the boat would stall. Any suggestions on what the issues are? I’m using a new 6 gallon tank this year so not sure what could be going on.thanks

[Yamaha3535]

As soon as I would unscrew the fuel water separator it would loose the suction and the primer bulb would loose the suction and go back to normal

[robert graham]

The new " government mandated" fuel tanks have no vents....all you can do is crack open the cap enough to vent it a bit...

[99yam40]

yep you have to let air in if you pull fuel out.
I thought the new ones would let air in but not out. so gas fumes could not escape into the atmosphere

my old plastic tank has a small thumb screw on the cap you loosen to allow air into the tank

[panasonic]

They are supposed to let air in through the one way vent...but they don't always work.

Tank blows up like a football when left out in the sun....junk. Crack the cap to let some air in is all you can do. Or return it and try another one.

[99yam40]

my C40 will suck the plastic tank in if I fail to open the vent, but never seen the bulb get sucked flat

[zenoahphobic]

Yep add me to those same answers