Hi guys. I have a 98 fatboy, and if I get a few fuel stains on the tank where it leaks from the right hand side cap. 

Obviously it is getting up a bit of pressure when the fuel get hot and blows off through the cap breather. 

Is there a simple fix for this?

Thanks. 

Yep buy new cap orings from a dealer or a set of aftermarket new caps

Thanks. I hadn't thought of new caps.

I have been doing my homework and it turns out that the aftermarket stretch tanks i have do not have an vent nipple.

So there is no vent line or vapor valve. I thought that might be the source of the problem. 

I am considering putting a t piece in the crossover line and installing a vent line and vapor valve.

It should stop any pressure build up, but I'd like a second opinon. 

Some people reckon it will leak fuel if the tanks are full and it is on its side stand. 

I figure if that happened it would happen with a normal vent line anyway. 

 

Not sure if I'm reading you right, but if you put a T piece in the crossover line as you suggest, I think any pressure in the tank will just push out fuel. You need the vent to originate somewhere in the airspace.

Someone who knows will probably chime in, but I guess there must be a faulty component somewhere and assume that they don't all do that. So Perthog is likely on the money with his new caps or O rings.

Just buy a vented fuel cap

It actually has a vented cap now and I think the fuel is leaking out of the vent in the cap when it gets hot and the pressure builds up. 

There is a crossover line that originates in the airspaces at the top of the tanks to balance the air pressure in both tanks. That is where i am thinking of putting the t piece. I'm hoping the pressure blows out the new vapor valve rather than the vent in the cap.

Heres a pic. 

 

 

Thanks for the help guys.