5 replies to this topic

[mouse]

Hi there,
just wondering if someone can help me out,i have a set of twin carbs on my mini with a small brass pipe coming from one of them ,that looks like a breather of some sort but i am told i should blank this pipe off to stop it drawing air in ,is this correct only i've tried it and the thing runs like a pig .
thanx Dave

[vasi]

I am sure there is a breather on HS carbs which vents excess pressure from the float chamber, block this up and you'll be forcing fuel up the jet and subsequently running way to rich.

[Hagar]

If it's next to the dashpot, and pointing up at an angle, it's the breather that should be connected to the rocker cover. (They often have a plastic 1/2" spacer over them - yours may have been removed) However, on a set of twins, the rocker cover breather may be connected elsewhere on the manifold/other carb. If this is the case, connect it or block it off. Leaving it open will have you running too lean on that carb.

If it's on the float chamber, and is horizontal, it's a breather (like Vasi says), leave it alone!

[Dan]

On a set of twins the breather inlets are on the inside of the pair, pointing at each other and up at an angle. They should be connected together with a Y piece and then into the breather system. As above, if there's a single small bore brass pipe on the float chamber it's part of the fuel system but it might not be a breather as theres about 36 different designs of the float chamber lid for all sorts of different cars and uses. If you don't know where the carbs are from then it could be anything. Stick up a picture of the float lids and someone will tell you what it's for if this is the case. You can't force fuel out of a jet, that's what needle valves (and float chamber overflows) are for.

[mouse]

On a set of twins the breather inlets are on the inside of the pair, pointing at each other and up at an angle. They should be connected together with a Y piece and then into the breather system. As above, if there's a single small bore brass pipe on the float chamber it's part of the fuel system but it might not be a breather as theres about 36 different designs of the float chamber lid for all sorts of different cars and uses. If you don't know where the carbs are from then it could be anything. Stick up a picture of the float lids and someone will tell you what it's for if this is the case. You can't force fuel out of a jet, that's what needle valves (and float chamber overflows) are for.

On a set of twins the breather inlets are on the inside of the pair, pointing at each other and up at an angle. They should be connected together with a Y piece and then into the breather system. As above, if there's a single small bore brass pipe on the float chamber it's part of the fuel system but it might not be a breather as theres about 36 different designs of the float chamber lid for all sorts of different cars and uses. If you don't know where the carbs are from then it could be anything. Stick up a picture of the float lids and someone will tell you what it's for if this is the case. You can't force fuel out of a jet, that's what needle valves (and float chamber overflows) are for.

On a set of twins the breather inlets are on the inside of the pair, pointing at each other and up at an angle. They should be connected together with a Y piece and then into the breather system. As above, if there's a single small bore brass pipe on the float chamber it's part of the fuel system but it might not be a breather as theres about 36 different designs of the float chamber lid for all sorts of different cars and uses. If you don't know where the carbs are from then it could be anything. Stick up a picture of the float lids and someone will tell you what it's for if this is the case. You can't force fuel out of a jet, that's what needle valves (and float chamber overflows) are for.

On a set of twins the breather inlets are on the inside of the pair, pointing at each other and up at an angle. They should be connected together with a Y piece and then into the breather system. As above, if there's a single small bore brass pipe on the float chamber it's part of the fuel system but it might not be a breather as theres about 36 different designs of the float chamber lid for all sorts of different cars and uses. If you don't know where the carbs are from then it could be anything. Stick up a picture of the float lids and someone will tell you what it's for if this is the case. You can't force fuel out of a jet, that's what needle valves (and float chamber overflows) are for.

[mouse]

 DSC00821.JPG   1.72MB   6 downloads  DSC00820.JPG   1.68MB   16 downloads

On a set of twins the breather inlets are on the inside of the pair, pointing at each other and up at an angle. They should be connected together with a Y piece and then into the breather system. As above, if there's a single small bore brass pipe on the float chamber it's part of the fuel system but it might not be a breather as theres about 36 different designs of the float chamber lid for all sorts of different cars and uses. If you don't know where the carbs are from then it could be anything. Stick up a picture of the float lids and someone will tell you what it's for if this is the case. You can't force fuel out of a jet, that's what needle valves (and float chamber overflows) are for.

hi
posted some pics to see if you can tell wheather it is just a breather or should it be blocked off
cheer dave  DSC00820.JPG   1.68MB   16 downloads