Triumph Bonneville T120R Setting the float levels

I get a miss fire at around 5000 rpm as the motor is running rich, I check the float heights, they are not done in the usual method of bending the tangs on floats. The floats are set and adjustment is acquired by repositioning the needle seat. This is a guide to setting the float level for an Amal 930 carburetor,with the standard settings near the end. After doing the job she runs a hole lot sweeter! :-D