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Discussion Starter #1
Hi guys,

When I pulled my carbies out of the bike (MC19) far too long ago there were a few hoses that didn't seem to be attached to anything. I figured I'd worry about it later.

Well, it's later and after trawling though the manual and scouring the net I'm yet to find anything helpful.

The first is a thin, shaped tube. I can't recall it having been attached to anything on the carbies nor does the tip look like it was attached to anything, but the other side is clamped out of the way and also detached. It's just sitting there.


The other two will be easier to identify. Unfortunately, I've found the manual to be almost useless. It shows them in diagrams without explaining their 'interfaces' or purposes. They were tied up and the ends tied together and positioned out of the way before I touched them. I'm guessing something to do with fuel, being where they are, but seems odd to have hoses not attached to something at both ends..


Additionally, I need to put a fuel filter in here somewhere as it currently doesn't have one. There is a connector between two pieces of fuel hose, I'm wondering if this would have been put there in place of a filter by the last owner (he was meaning to replace it but bought the wrong filter) or if it has some purpose I'm unaware of?


Cheers.
 

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the first one connects to your fuel tank
pretty sure coz i've taken my tank out 5-6 times in the last 2 weeks
i think its just a drain pipe or something, coz i dont remember it being connected to anything (i might be wrong though)
i'll check again tomo when i take my tank out

the other two weren't connected to anything on my bike so im assuming its the same for yours since i have an mc19 as well
and it was working fine

not sure about the last one
again i'll have a look tomo and maybe post a pic of mine
 

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Discussion Starter #3
viper33 said:
the first one connects to your fuel tank
pretty sure coz i've taken my tank out 5-6 times in the last 2 weeks
i think its just a drain pipe or something, coz i dont remember it being connected to anything (i might be wrong though)
i'll check again tomo when i take my tank out
Thanks mate. You know, I've totally neglected to look under the tank. I wasn't planning on leaving my bike stripped down for so long, and now I've forgotten.

the other two weren't connected to anything on my bike so im assuming its the same for yours since i have an mc19 as well
and it was working fine
That's good news. Open ended hoses tend to worry me.

not sure about the last one
again i'll have a look tomo and maybe post a pic of mine
Cheers mate. Would be appreciated! :shy:
 

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the second pair of hoses is not meant to be connected to anything. someone told me it was so excess fuel can flow out? or something who knows but 100% they arent meant to be connected to anything
 

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francisz said:
the second pair of hoses is not meant to be connected to anything. someone told me it was so excess fuel can flow out? or something who knows but 100% they arent meant to be connected to anything
True, my bikes have 2-3 hoses for excess fuel and stuff.
 

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oh by the way, with that lil black plastic box, connected by a hose to your carbs, was that how it was when you took out the carbs? mine had a hose from the airbox connected to my carbs, and that lil black box and the hose connected to the engine.. i wonder.. is it meant to be the other way round?
 

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francisz said:
oh by the way, with that lil black plastic box, connected by a hose to your carbs, was that how it was when you took out the carbs? mine had a hose from the airbox connected to my carbs, and that lil black box and the hose connected to the engine.. i wonder.. is it meant to be the other way round?
Yep meant to be other way round.
 

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dazz245 said:
francisz said:
oh by the way, with that lil black plastic box, connected by a hose to your carbs, was that how it was when you took out the carbs? mine had a hose from the airbox connected to my carbs, and that lil black box and the hose connected to the engine.. i wonder.. is it meant to be the other way round?
Yep meant to be other way round.
okay cheers!!
 

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Discussion Starter #10
Yeah, that's how it was... I'm not quite clear on how you're saying it should be though.

I have the small box as it is, and a hose going from the air box to the engine. Is this not correct? Everything seems to be in its spot in this way.
 

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The small box goes on the carbs and the engine is connected to the airbox. You might want to check the filter in the small box(if it hasn't fallen apart).
 

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I'm not sure of the correct terminology, but that hose and the small box are a vent for the diaphragms in the carbs.

When the slides move up and down the volume on each side of the diaphragm changes, so the top of the diaphragms have to be vented to atmosphere in order to work properly. I'm not sure why Honda couldn't have worked out a way to do this within the airbox, but they didn't.

Air flows both ways along the hose. If you don't have a piece of oiled air filter foam in the small box, your carburettors are sucking unfiltered air, which is obviously not good. It is only a small amount, though.

It is important to oil the foam. It is the oil that traps the dust, not the foam. Old sump oil will do perfectly well if you don't have any air filter oil. It only needs a small amount of oil, there is no need to completely soak the foam.
 

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Discussion Starter #17
Ah, well if it's a vent rather than an intake then I can see why it's not a part of the air box. Does anyone know what the little filter is identified as? I probably should replace mine.

Thanks for the info Stavros. :)

If someone could let me know about the fuel filter before I put my left fairing back on that would be great!
 

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No worries. My pleasure.

The genuine Honda filter for the vent is probably quite expensive, if it is available at all.

If you need a new filter and you don't have an old foam air filter to cut up, you can buy sheets of air filter foam from the bike shop for about $20 or so, but ask about offcuts because you'll only need a fraction of one sheet.

If you are feeling extra ghetto you could just stuff the box with an oiled Chux or two. I know quite a few dirtbike riders who use oiled Chux cloths as precleaners in their airboxes and it is amazing how much dirt they can collect and how clean they keep the stock air filter.

As a wise man once told me, if it is stupid and it works then it is not stupid. :p

As for the connector, I'm not sure what purpose it serves (it may be a one-way valve? Don't quote me, I'm guessing) but I have seen it on quite a few MC19s. I would put the filter between the tank and the fuel pump.
 

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hey i got my mate to take a couple of pics of my fuel lines today
now im waiting for him to upload them and send them to me
soon as i get them i'll put them up here
 

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Discussion Starter #20
Thanks again Stavros. I like your idea for a replacement filter. :p

Thanks to you to Viper, I didn't expect anyone to that much trouble!
 
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