fuel tank breather

[gazz85]

my fuel tank is making a high pitch noise and stops when i open up the fuel cap.

that to me is saying that the breather is blocked.

i have checked the breather pipe and it is clear all the way through.

what i dont understand is, the breather pipe starts next to the hole for fueling runs through the tank and out the bottom.
it doen not allow air to get into the tank at all.

can someone please explain to me apart from directing fuel that has been spilt to the underside of the bike, what else is it for?
and also how does the tank breathe?

i am hoping this is going to be the problem to my bike cutting out for a second while riding.

regards, gaz...

[Doofer]

Gazz,

There is an air vent in the fuel cap, this will be what is causing the whistling noise, chances are it is partially blocked.

If it were completely blocked your bike will behave as if it has ran out of fuel shortly after starting.

The drain that you have described is for allowing water or spilt fuel to drain away from the filler area rather than enter the tank when you open the cap.

You may be able to clear the vent in the cap, I don't remember how easy it is to access and no longer have a divvy to check against, but so long as your bike is running well then you need not worry about it being blocked, admittedly the noise can be annoying, especially in summer when changes of pressure in the tank seem to be more noticable with the warmer weather

Doof

[gazz85]

cheers doofer.

i had the fuel cap aprt but could not see where the small pin hole in the bottom of it went to/worked.

i will take it apart and have a look again.

the blockage i think is causing my bike to cut out while riding, well im hoping it is the cause, lol.

regards, gazz.

[gazz85]

i took the cap apart and it was grubby inside, gave the gasket a wipe down and took out the vent bits and blew them out, put it back together and could hear it suck really well.

but still aint sorted them problem i thought it might of but one problem sorted i guess.

cheers for the help...