Pressurizing Fuel Tank (Fix Pics inside)

[Claviger]

Ok so this has me a bit baffled.

My fuel tank is pressurizing while riding. When I got home today I opened the cap and a healthy dose of pressure came out. Closed it back up, about 2-3 minutes later, open it up, and more pressure was relieved?!

What in the actual f...?

 

[Neville Lush]

This will effect your tuning........

 

[Claviger]

Indeed, I really need to figure this out, its really irking me lol. Guess I'll be tearing into it this weekend.

I can't even begin to theorize as to wtf is actually causing it, so weird.

 

[Ishrub]

Crimped breather hoses

 

[barbagris]

Crimped breather hoses

Was going to say the same. Though it need not be a HARD crimp (i.e. trapped). The rubber hoses have to be fairly carefully routed or they will bend enough to close the ID on itself. Have somebody raise and return the tank a watch the hoses.

 

[Claviger]

The drain and vent for overfilling I know are fine, but I’ll have to root around in what used to be the EVAP system to check for something that’s not right.

 

[WyldCFH]

Do you have a fancy aftermarket filler cap? Does it have a gasket? Could be the gasket falling and sealing the vents.

 

[Claviger]

I do have an aftermarket cap, going to check all that today, the problem should be easy to spot if it’s a line.

 

[Claviger]

Problem identified

Fancy pants gas cap isolates the area between the actual tank and the opening with no flow between that path and the vent lines.

A small hole will be added, I knew it had to be something stupidly simple.

@WyldCFH MVP for pointing my brain in the right direction

 

[WyldCFH]

Glad I could help