Small hose on carby of SR250?

[rabbittingman]

I am going to get the first price for the most stupid question of the year,,but here goes...blush blush.....I have got a 1985 yamaha sr250,and between the carburettor and the piston,where the fuel goes into the chamber,there is a small rubber hose that comes of the top,it just dangles there,it is the same size as the petrol hose,from the tank into the carby, question is...what is that hose for? and where is it suppose to fit on to? I cant see nowhere where it is to fit onto. I looked at pics, and it looks like it fits somewhere on the petrol switch...but where...sorry to make an idiot of myself but I would really like to know! tia

[bsasuper]

Its a vacum point, could be for the petrol petcock.

[rabbittingman]

is it inperative that it is connected? as the bike seem to run ok without it. it is blocked off on the end.

[quickbuck]

I suspect, from what you describe, it is probably the vacuum port hose.
These are only used on some fuel cocks, and usually off later model bikes (or bikes destined for different markets).
As it is blocked off, you may well now have a tap that doesn't require a vacuum hose to actuate it.

If you can, can you get a picture up?

Oh, and the most stupid question is the one that wasn't asked.

[rabbittingman]

I took a pic...trying to figure out how to add it now...lol

[rabbittingman]

the pic I took ,I think I sent it

[neels]

Judging by the screws, it looks like someone might have changed the fuel tap to one that doesn't have a vacuum connection. Some have a vacuum diaphram to shut off the fuel when the engine isn't running, others don't, so if it's been changed there's nowhere for the hose to go.

If the bike is going OK as it is then just plug it, a lot of bikes have caps over the vacuum inlets which are there to connect gauges to when balancing, just track one down and stick it on.

Edit: Where does the hose off the side of the carb go, I've got an extra one floating on my XL and can't figure out where it should connect to.

[rabbittingman]

thanks...if it is not something of any importance I leave well alone...the hose is blocked off on the end and the bike runs fine...so ....when it aint broke.dont fix it...thanks again!!

[quickbuck]

Edit: Where does the hose off the side of the carb go, I've got an extra one floating on my XL and can't figure out where it should connect to.

I would say that is a vent for your carb bowl.
If the floats get stuck in the bottom of the carb, then fuel will flow out of there....... Otherwise, on a normal day, it is just a reference to atmosphare for your carb bowl.

OR, it could be something else.. Is the RC tthe twin carb model? Or am I thinking of the RE?

[bsasuper]

What neels said. Its not a carb vent.

[neels]

OR, it could be something else.. Is the RC tthe twin carb model? Or am I thinking of the RE?

It's a single carb, the hose is higher than the float bowl, sort of off the side of where the slide is in the carb body. I'm wondering if it's for a vacuum fuel tap but my bike doesn't have one, so the carb might not be the original one for the bike, not a big deal I've just stuck a screw in the end of it and it seems to go ok.

Apologies for the minor thread hijack.