why does my gas tank keep swelling?

[Pointhunter75]

It done it twice last week. I took the 1.5 lb vent out of the left of the hull and sprayed carb cleaner followed by compressed air. Few days later same thing. Replaced with a new check valve yesterday and today same thing. hoses are routed correctly. Makes no sense. Any ideas?

 

[1983]

Just had psi problem on my 96 xp, was actually first thing I fixed upon purchase.

The one you changed allows tank to vent pressure out and not in. The vent beneath the handlebars ( little black/white one way check valve ) allows air into the tank via a grommet near latch striker for hood. That check valve only allows air into fuel tank.

While riding for a while or after letting ski sit in sun, if you take fuel cap off, does the fuel tank expel pressure/hissing sound and kind of push/shoot cap off the ski? as if tank is bulging with pressure? If so one of the vents isnt working, vent lines are plugged, or vents are in backwards....


Rob

 

[Pointhunter75]

Rob both of those vents are brand new. Facing the correct directions with brand new lines on the whole fuel system. That's why it's so confusing. The lid does blow out. All I know to do is take the hose off the baffle and put my pop off gauge on it. I can blow hard through the new vent out valve. Couldn't through the old one.

 

[Pointhunter75]

The baffle was removed and cleaned too...

 

[Coastiejoe]

Try this,,, let it happen again, and when it does, remove the new vents you installed. If it stays puffed up, then you will have to go closer to the tank to determine the issue. But I bet it it shrinks back down once you remove the vent.

 

[Pointhunter75]

Good idea Joe. I'll try that.

 

[JJinSC]

Yeah, this has to be a bad/wrong vent or clogged vent line. Like the other poster said, one vent lets air in (check valve) and one lets pressure out. (Vent valve). Remove the vent valve next time it happens and if pressure releases, the vent valve is the issue. If not, remove the vent line from baffle. If pressure releases, your vent line is clogged.

 

[1983]

I would try above suggestions, and clean each individual vent line from grommets in hull of jet ski all the way down to fuel tank sending unit assembly.

Rob

 

[Pointhunter75]

Pulled the valve and it blew. Guess I got a bad valve. Just my luck. I don't have to blow very hard really to open the valve. Seems like it would work. I'll notify the seller and get another. Thanks for the help

 

[1983]

The new lower hull valve? It's allowing air in which direction or is it blocked completely in both directions?

 

[Pointhunter75]

Yeah the tank out vent that goes out the hull. It's new and so is the in valve by the hood latch. The out valve will blow through but for some reason it's too stiff for the tank pressure to open it.

 

[Pointhunter75]

Another new valve and same problem. Took the hose off at baffle, valve off and no restrictions. Must somehow be clogged in the baffle which was cleaned weeks before I got this thing going a few weeks ago. Guess I'll pull the baffle again and check my non working fuel gauge too.

 

[JJinSC]

Make sure you are putting the right valve in the right direction/orientation. If you put the vent valve on backwards, it would act like this.

 

[Pointhunter75]

It's all correct.