1.5" carb linkages

[Alex'n'Ane]

I have a 1.5" HS4? carb with the heated inlet manifold, im not 100% sure what it is off, but i suspect a mini. My question is what needle would be best (most reliable) for an otherwise standard tune 1098 engine, still with standard cast exhaust manifold. And how would i identify what needle i already had?[frame][/frame][frame][/frame]

[bmcecosse]

Yes it's an HS4 - just make SURE the float bowl is dead vertical when it's on the car. You can adjust it if necessary by filing the angled spacer which secures the bowl to the carb body. I would try whatever needle is in the carb - slacken the screw and pull it out of the piston - the code letters are typed into the side of the shank. For a modified engine, the AAA needle is commonly used as ca starting point - but it's very likely your carb is indeed ex Mini - and the needle in it won't be too far away. That filter looks fine - and don't connect the water heating! And yes! It has the little brass pipe on the side of the carb body to take the nasty fumes away from the rocker cover breather - use it! The extra pipe on top of the float bowl is just a vent/overflow as someone mentioned earlier.

[minor_hickup]

ABP would be the standard needle but that air filter would probably make it a little lean at the top end.

[Alex'n'Ane]

Does anyone have any pictures or can describe the way the linkages attach to the hs4 carb, which of the two bracket holes does the accelerator cable need to go through? And how does it attach to the carb leaver? Also how is the choke cable secured?
And finally is the fuel intake the longer or shorter pipe on the float bowl?

[twincamman]

I've never noticed an overflow on the HS4 before. The longer tube is the fuel inlet, note it has a lip on it to stop the fuel hose slipping off under pressure.
I would recommend that you attach a bit of piping to the overflow and route it well away from heat sources such as the exhaust, just to be on the safe side.

[Alex'n'Ane]

Also which one is the vacuum advance?

[bmcecosse]

Yes - long is fuel IN. In the first picture - the acc cable sheath fits into the little vertical socket and the inner wire will be secured by the nut on the moving cam - with the spring attached. The choke sheath will fit into the other angled socket, and the inner will attach to the cam that moves the jet assembly - can't see too clearly in that picture but should be obvious enough on the carb. I don't see a vac advance take off - you may need to use a plastic manifold-to-carb spacer with vac advance pipe fitted if there isn't one on the carb itself - or on the manifold.

[welshrat]

Yes it's an HS4 - just make SURE the float bowl is dead vertical when it's on the car. You can adjust it if necessary by filing the angled spacer which secures the bowl to the carb body. I would try whatever needle is in the carb - slacken the screw and pull it out of the piston - the code letters are typed into the side of the shank. For a modified engine, the AAA needle is commonly used as ca starting point - but it's very likely your carb is indeed ex Mini - and the needle in it won't be too far away. That filter looks fine - and don't connect the water heating! And yes! It has the little brass pipe on the side of the carb body to take the nasty fumes away from the rocker cover breather - use it! The extra pipe on top of the float bowl is just a vent/overflow as someone mentioned earlier.

Hi, interested in why not connect the water heating, would this apply if inlet was fitted with hiff 44 carb. Inlet is off a MG metro I've been told.

[bmcecosse]

For best power you want the coldest possible air/fuel mix into the engine. Twin carb manifolds don't have water heating for good reason......