I have a 1991 Super Glide Low Rider Custom FXLR. My Old Tank has a Vent but I got a New Tank and they did not put a Vent in it. They screwed up and told me a Vented Gas Cap will be just fine. But they are all for Fuel Injection not for CV Carbs.

So the Pressure causes my new SE Big Bore Carb to Over Flow, slinging Gas on my rear tire and that wast a lot of Gas... The Bike should be Getting 53 MPG and it's down to 36.3 MPG.

It's time to get another Gas Tank constructed correctly cause a CV Carb Bike is not Fuel Injected. That Cap only lets a Little air in when it needs its so the Fuel is not flowing as it should.