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Fuel tank breather NC29
Posted: Wed Apr 13, 2011 8:06 pm
by cbr400rrn
Could anyone tell me or have any pics on where on earth the fuel tank breather is as i think the tank isnt letting air in to stop it pressurising. Its difficult to open the fuel tank cap when the bikes been run.
There are no other issues with the bike yet, but it is a pain in the arse trying to fill up at petrol stations and not being able to get the tank open.
Re: Fuel tank breather NC29
Posted: Wed Apr 13, 2011 9:02 pm
by leopard_pagan
it has no pipe outlet as it breathes through the cap, mine hisses at me in summer when i move the bike after being sat in the sun. it does have an over spill which is under the tank in to a rubber cup.
get a pipe cleaner and clean all round the cap..
Re: Fuel tank breather NC29
Posted: Thu Apr 14, 2011 10:24 am
by cbr400rrn
When i say difficult to open we are talking 10 minutes of turn key and cap pops up slightly but i'm unable to just lift it up, i know it breathes through the cap but just wondered if anyone has come across it before and could point me in the right direction if you know what i mean.
How does it breath through the cap is what i would like to know

Re: Fuel tank breather NC29
Posted: Thu Apr 14, 2011 11:58 am
by tanuki
there is a hole in it.
Re: Fuel tank breather NC29
Posted: Thu Apr 14, 2011 1:29 pm
by Davez29
Is it the vacumn stopping the cap from opening or could it just be the side catches? Sounds like it is to me if its popping up slightly. Open your cap, put a rag around the cap, spray with wd40 into the moving parts of the cap, inside and out, side catches, lock and hinge, push the catches in with your fingers to gain better access, turn the key also. My guess is, it will work after this.
Re: Fuel tank breather NC29
Posted: Thu Apr 14, 2011 8:11 pm
by cbr400rrn
tanuki wrote:there is a hole in it.
Cheers
It isn't the catches as i have cleaned them all and sprayed a little oil in there, they move freely and the key turns without a problem.
Re: Fuel tank breather NC29
Posted: Thu Apr 14, 2011 8:38 pm
by Davez29
cbr400rrn wrote:It isn't the catches as i have cleaned them all and sprayed a little oil in there, they move freely and the key turns without a problem.
Very surprised hearing this, main reason being I just had that very problem last month, the catches were just gripping the edges, had to spray quite a bit to get them working fully. But I bow out gracfully and allow you find the answer.
Re: Fuel tank breather NC29
Posted: Fri Apr 15, 2011 10:02 am
by cbr400rrn
Durka Durka wrote:cbr400rrn wrote:It isn't the catches as i have cleaned them all and sprayed a little oil in there, they move freely and the key turns without a problem.
Very surprised hearing this, main reason being I just had that very problem last month, the catches were just gripping the edges, had to spray quite a bit to get them working fully. But I bow out gracfully and allow you find the answer.
No need to bow out my good man, thankyou for coming up with that idea. It will help if someone else has a problem like this and finds your post as theres not much regarding the Nc29 fuel tank issues yet.
Re: Fuel tank breather NC29
Posted: Fri Apr 15, 2011 12:31 pm
by tanuki
I had a broblem with a tank breather years ago on a GSXR, if your tank is presurising you will hear it hiss as soon as you turn the key, I dont think that is the cause of your sticky fuel cap as if your tank was presurising the fuel would stop flowing.
Re: Fuel tank breather NC29
Posted: Fri Apr 15, 2011 10:15 pm
by cbr400rrn
Hmm going to have to take it off and have a fiddle around with it me thinks.
Thanks very much