Fuel leak from overflow when forks are bounced up and down

So whilst testing if my fork seals had reseated after using a seal mate(they had, well worth the £5!)

I was bouncing the front end of the gixxer up and down as much as i could with the front brake on, and noticed fuel coming out from some sort of overflow pipe. Anyone know why this would happen? It doesnt come out if you bounce it normally, but if you really tug it then it come out a bit.

I realise there is an overflow from the petrol cap, so maybe its coming from there however the tank isnt full, maybe 1/2 or 1/3 full but i suppose its still an option. Just dont want fuel coming out everytime i hit a bump!

Bikes a gsxr 1999 srad 600

[jambo]

The fuel tank has a breather pipe that runs from the filler mouth to a drain at the back. If this gets blocked it can fill with water and rust through. When fuel sloshes about it can make it through the hole and down the line. To check this, take some rubber hose. Fit it to the drain at the back and block the drain at the top and blow into the pipe. It should be air tight, if you can hear air making it into the tank you have an issue.

Jambo
Sent from my thingie

So i need to blow from the overflow and cover the hole at the filler cap and hear for bubbles basically?

[jambo]

Or a hiss.. be aware the tank drain its often linked to other drains, so you need to be able to see the pipe at the rear has only one pipe connected and you're blowing in that. Put your finger over the hole at the filler neck with the tank open. If all was well you'd be able to blow through with your finger off to show the internal pipe isn't blocked, and get pressure with your finger sealing the drain hole at the top showing the internal pipe isn't leaking.

Jambo
Sent from my thingie

Wouldn't it likely leak every time you filled the tank?

[Fallout]

My Tiger has a similar issue mate. If you overfill it obviously goes out of an overflow pipe. If I brim the Tiger upright then put it on the sidestand it ****es out. It's done it twice now. Bit of a bugger as the seal on the cap looks good. I just fill it on the sidestand now so the level isn't too high.

I wouldnt know yet if it happens when you fill up coz ive never ridden it myself, cant until aug for my restriction.