Hi,
You haven't got the cable too tight have you. I find it works best just on the first notch not the second. It kind of looks like it should be on the second though. Also the inner cable needs to be almost straight where it protrudes at the bottom end. I have had to reshape a few so they work better. As Norm says they work much better if you do his carby mod which gets rid of the choke and makes the cable path much better. Start on full throttle.then.
Jeff