Long ongoing issue on my 848. Fuel occasionally leaks from the breathers. If the breathers are blocked it escapes from the edge of the filler cap instead. If I blow into the breather tube and cover the outlets at the top I don't get any air escaping elsewhere so I think the internal tank pipes are intact. I appear to be missing a rubber nipple that connects one of the holes to the pinhole in the cap. Could anyone advise if I'm missing any other gaskets from the filler area? Might a blockage within the cap itself cause this? Edit: having check previous receipts to see if the PO suffered it looks like J&L diagnosed it as needing a new tank. (Nice of them to let me know that) as long as the internal pipes are sound I can't think of a reason a new tank would be required.
There is a valve in the cap for breathing. It could be blocked or assembled wrong. It shouldn't make fuel come out anywhere though.
Solved - So after further investigation it appears there was some leaking through the breather pipe inside the tank. Maybe increased ethanol related? at any rate blocking the breather and allowing it to vent through the overflow line instead seems to have worked fine.
I had the same issue the other day, i think when the bike sits in the sun, fuel leaks out the top of the filler cap. I stripped some fairings off to check the carbon filter wasn’t blocked to find it wad been removed by a previous owner. The fuel breather wasn’t blocked but the drain that’s supposed to divert any spilt fuel in the filler cap was. I’ve unblocked it but I don’t think that’s gonna stop the tank from pressuring when warm so it will probably vent it out the overflow for the time being until I can figure out what’s missing or not working properly.
