Vintage Horticultural and Garden Machinery Club

If you look at your photo 1106 you can see a threaded hole at the top of the carb. this is where your mixture control screw should be, it is a simple bolt, with a lock nut, this controls the mixture of air and petrol, yours is missing, so you must have a weak mixture, you screw it in to richen the mixture, should be an easy fix.