08-03-2024, 09:07 AM
Hi
The 26VA should not need "flooding", but if you haven't used the car for a few days the float bowl may empty a bit through evaporation. This can be overcome by using the priming lever on the fuel pump to manually pump fuel until the needle valve cuts off with the bowl full. If you don't do this, you have to wait until the engine turning over on the starter has done the same job. An alternative is to turn the engine over on the handle half a dozen times (ignition off), which saves having to open the bonnet and delve in.
The 26VA choke is an air strangler. By restricting the air supply, a lowering of air pressure occurs downstream of the strangler flap, which "sucks" fuel out of the jets. Because the air flow at cranking speeds is so low, the strangler must cover the passage almost completely (it has just a small hole in its centre) so it's worth checking that the cable and cam mechanism are doing their job properly.
If for some reason the fuel level in the float bowl is too low when the needle valve cuts off, this won't help matters.
Once fired up, erratic idling speed can be a sign that there is an air leak somewhere in the carb or inlet manifold. When idling, manifold vacuum is high, so even a tiny leak will result in extra air being pulled in and weakening the mixture. Check the manifold gasket for leaks, the carb to manifold flange and the throttle spindle for wear. Once underway, small air leaks like this have much less effect on running.
The 26VA should not need "flooding", but if you haven't used the car for a few days the float bowl may empty a bit through evaporation. This can be overcome by using the priming lever on the fuel pump to manually pump fuel until the needle valve cuts off with the bowl full. If you don't do this, you have to wait until the engine turning over on the starter has done the same job. An alternative is to turn the engine over on the handle half a dozen times (ignition off), which saves having to open the bonnet and delve in.
The 26VA choke is an air strangler. By restricting the air supply, a lowering of air pressure occurs downstream of the strangler flap, which "sucks" fuel out of the jets. Because the air flow at cranking speeds is so low, the strangler must cover the passage almost completely (it has just a small hole in its centre) so it's worth checking that the cable and cam mechanism are doing their job properly.
If for some reason the fuel level in the float bowl is too low when the needle valve cuts off, this won't help matters.
Once fired up, erratic idling speed can be a sign that there is an air leak somewhere in the carb or inlet manifold. When idling, manifold vacuum is high, so even a tiny leak will result in extra air being pulled in and weakening the mixture. Check the manifold gasket for leaks, the carb to manifold flange and the throttle spindle for wear. Once underway, small air leaks like this have much less effect on running.