Fuel leaking when dropped

[Lyra]

I dropped my ninja 250 while practicing a while ago, and I noticed that the gas cap leaks fuel at kinda an alarming rate. I managed to get it up before I lost to much, but what are your thoughts on that? I asked the dealership and they said that was normal, but my last bike didn't leak, and it seems like an odd choice to make a starter bike extra flammable when dropped. As it is I can't practice after ten, because I don't want to be the person who totaled her bike because of a two mile an hour drop...

[yen_powell]

They leak sometimes when the tank is quite full and less so when the tank level is lower.

On carbed bikes a drop can sometimes stop the bike starting straight away which can panic a new rider, not sure what happens with a fuel injected bike as I haven't dropped one of those yet. Just give it a minute or so if it doesn't start straight away and then try again.
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Blackmail is a nasty word........but not as nasty as phlegm!
XT1200Z and a DR350 in bits

[xX-Alex-Xx]

FI bikes start right up as soon as the tip over sensor has sorted itself out. (Apparently)
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DILLIGAF

[BigTim]

[Hong Kong Phooey]

What year is the bike? Some leak through the bolts holding the cap surround.
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'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[jaffa90]

Check the cap rubber ring / s and the tank mating surface.
I would not expect fuel pi**ing out of a breather hole in the cap.

[Easy-X]

Petrol's very good at finding its way through even the slightest of cracks or gaps - gaps small enough to not let oil or water through.
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Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[MCN]

All tanks must be vented or they reach a state where atmospheric pressure is greater than the weight of the fuel (other fluid) and the effect of vacuum inside thebsealed tank. Therefore, the fuel will be trapped inside.
Tanks vent through the cap or via more sophisticated means such as pipes/tubes leading to a lower point on the frame under the tank.
If you have the latter type there will be a small hole or more in the tanks cap fitting. These allow the tank to vent but will prevent fuel spilling out if leaned or dropped.
If the seal on the cap is old then all the above is redundant as the seal can simply leak fuel.
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Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[MarJay]

All the bikes I've seen dropped have leaked a bit through the filler.
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.