Help please "Whats This Do"

(RIP) Mark H

Formerly known as Easyrider5258 (Mark)
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Can anybody ID the purpose / use of the oblong shaped plastic thing I have circled in the illustration, it has just dropped inside my fuel tank!! is it OK to leave it to lie in the bottom of the fuel tank for a while or does it have some vital function, I cannot find any reference to it's purpose in my manuals or on the net :nenau
 

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AFAIK its part of the breather to allow air in when fuel goes out to stop it crushing the tank (or at least making opening the fuel cap devilishly hard)
 
Is it not part of the thing that tells you you've just run out of fuel:confused: i.e. fuel gage.

That me asking the same question then:blast
 
It's the float for the petrol gauge.

you can leave it floating around in there, but your petrol gauge won't work :comfort
 
It's the float for the petrol gauge.

you can leave it floating around in there, but your petrol gauge won't work :comfort

I dont think it's the float for the fuel gauge the part it's attached to doesn't move and is attached to the neck of the fuel filler.............. I'm thinking / hoping it might be sockpuppets answer............
 
It's the float for the petrol gauge.

you can leave it floating around in there, but your petrol gauge won't work :comfort

Put the spanner down son and step away from the technology. I'm sure we can find you some house work to do instead :D
 
It is indeed the tank breather 'thing'. It has a tiny hole in its top surface to let air in (via one of the breather hoses next to the brake pedal) as fuel is used .

With it 'dropped off', you'll find that if you fill your tank, fuel will pour out of the breather hose. Don't fill above 2/3 (ish) full until you're replaced it.

And as you've got to remove the fuel pump inspection cover and the filler neck to replace it (unless you empty the tank completely and give it a good rattle upside down to get the 'thing' out of the filler neck), it's a good time to check all the internal hoses and change your fuel filter if its not been done for a while ;)
 
It is indeed the tank breather 'thing'.

And as you've got to remove the fuel pump inspection cover and the filler neck to replace it (unless you empty the tank completely and give it a good rattle upside down to get the 'thing' out of the filler neck), it's a good time to check all the internal hoses and change your fuel filter if its not been done for a while ;)


I was wondering if it might be reachable and replaceable just by removing the filler neck. without touching the pump cover.
 
I was wondering if it might be reachable and replaceable just by removing the filler neck. without touching the pump cover.

I think you'd have to be lucky.
Given the shape of the thing and what it's made of (i.e. smooth and round and plastic) it'll be impossible to hook or grab with a magnet and there's no way you can get your hand in through the filler neck and into the lobes of the tank. It'll also probably be in the right hand front lobe which is where the fuel level float switch lives - this will get in the way and would be easily damaged if you dug around for it with bits of wire etc.

I'd either completely empty the tank, turn it upside down and 'manoeuvre' it out of the filler neck or take the fuel pump cover off. If it were me, I'd just bite the bullet and do the latter - not much more work once you've removed the tank.

(Guess who's had his tank to bits three times in the last couple of weeks :rolleyes: )
 
what I was doing was resealing the rubber O ring under the filler neck, I've just got the bike and there's a smell of fuel when full, I found the o ring was not seated correctly allowing fuel out when the tanks full or nearly full, I've cured that and got it seated correctly because if you turn the tank upside down no fuel leaks past the filler neck joint, However it was a bugger to do and the part in question dropped off just when I got it seated correctly, I'm thinking I,d better do it cos I'm off to the gorges of verdon in a few weeks and defiantly want a few full tanks :thumb

Thanks for all the replies :)
 
I was wondering if it might be reachable and replaceable just by removing the filler neck. without touching the pump cover.

It's very diffcult to do it this way I did do it on my 94 R1100RS but make sure you have a spare filler neck gasket they swell as soon as they hit the air

It's worth a try but probably easier to drain the tank and remove the pump assembly so you can remove the breather and drain hoses to allow you to lift the filler assembly out easily and refit the non return valve doofer
 
what I was doing was resealing the rubber O ring under the filler neck, I've just got the bike and there's a smell of fuel when full, I found the o ring was not seated correctly allowing fuel out when the tanks full or nearly full, I've cured that and got it seated correctly because if you turn the tank upside down no fuel leaks past the filler neck joint, However it was a bugger to do and the part in question dropped off just when I got it seated correctly, I'm thinking I,d better do it cos I'm off to the gorges of verdon in a few weeks and defiantly want a few full tanks :thumb

Thanks for all the replies :)

:thumb2 When you replace it, make sure you get it the right way up (little hole on the top surface).

Also a good opportunity to clean out the filler neck water drain hose etc.

Just call it a full 'fuel tank service' - you'll feel better about having to do it :D
 
If its only got one wee hole in it it may be floating. Put more fuel in and see if it floats into view. You'll need to remove the filler assembly again.

The "O" rings shrink if left in the sunshine for a while as the fuel evaporates out of them.
 


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