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Discussion Starter #1
Hi Fellas,
I don't know if its something they all do but my RC8 fuel tank is under vacuum after a run or pressurised if I open the filler cap when it's cold then leave it in the sun. The filler cap seems to seal the tank so well that the fuel pump actually sucks the sides of the tank in! One fill up recently the tank was obviously under pressure and shot petrolly fumes out when I opened the filler - good job I'd put the fag out!
Any thoughts? I've searched the posts and couldn't find anything.:confused:
 

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I know of one bike that had to have the tank replaced because it deformed so much due to a vacuum created in it while running. As per GFs post... back to dealer and get them to remove the tank and check that all the hoses are running correctly
 

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Discussion Starter #4
Looking at the fuel cap, it looks as though it seals completely against the tank, the breather comes off outside of the cap. Unless theres a tiny air hole I haven't seen?
 

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Looking at the fuel cap, it looks as though it seals completely against the tank, the breather comes off outside of the cap. Unless theres a tiny air hole I haven't seen?
i haven't personally had the tank off mine, but it will be like any other superbike tank. there are breather pipes i imagine under the tank, if there is a kink in one of them, and isnt breathing properly, a vacumn is created
 

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Yup, breather pipes on both sides towards the rear of the tank (you have to lift the tank to gain access to them)
 

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Discussion Starter #8
Thanks for the replies Fellas, tank lifted found the breather hose that comes away from the tee piece was pinched - hopefully soted now. KTM are funny though, you've got this nice quick release self sealing fuel hose coupling but the other tank fittings are an arse to get too. And the side panels below the seat, you need to move them outwards to clear the breather hose connection on the tank rear but you can't get to one of the screws holding them without removing the tank first. Never mind you need the bad to appreciatethe good!
 

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Hmmm, never had to touch those side panels on mine when removing/refitting the tank
 

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Discussion Starter #10
Looks like it's back to the dealer, 100 odd miles yesterday (while the footba was on) and the tank was sucked in again.
 

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Discussion Starter #11
Removed the fuel cap on Friday, following a chat with an Ex-Bracken motorcycles mechanic, and found the hole that's supposed to go through to the tank wasn't. Quick hand drill later-all sorted. Anyone else had this? Incidentally, talking of Bracken, they are no longer in business, the recievers were called in last week apparently. Drat, I was going to go there for a service.
 

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Ahhhh... might explain why I couldn't get phone calls to Bracken answered last week. Sad news, heard good things about them. Another KTM dealer bites the dust then :-/

Glad you got the tank issue sorted mate
 

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Discussion Starter #13
Yeh it's odd how quickly things change. I was only speaking to the sales man Andy a couple of weeks ago and he couldn't have been more helpful. They, the staff I mean, didn't know 'til Thurs last week. One of the RC8 mechanics has moved to Inmoto in Croydon so I'm going there.
 

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Removed the fuel cap on Friday, following a chat with an Ex-Bracken motorcycles mechanic, and found the hole that's supposed to go through to the tank wasn't. Quick hand drill later-all sorted. Anyone else had this? Incidentally, talking of Bracken, they are no longer in business, the recievers were called in last week apparently. Drat, I was going to go there for a service.

I did say to check in the cap in my original post :rolleyes:;) Glad its now sorted.
 

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Discussion Starter #15
You did man, I was focused on the breather hoses though. Have you taken the filler cap apart? It's well complicated, for a filler cap I mean, I suppose so it lets air in but doesn't allow fuel out if you stack it.
 
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