I found that the standard 1 1/16" new Amal carb on my bike, was feeding to 1" port in the head!
I was advised that any step in the inlet tract would affect the performance.
I filed out the head to match. I fitted the fibre heat insulating plate on to the head with the bolts. I was able to see
how the holes matched very easily.
The holes in the plate were larger than the bolts, so a step would certainly still be possible.
I made alloy sleeves to glue into the plate, with exact fit on the bolts.
With the plate now unable to be out of line, I could cut the head to match the plate exactly.
With the cylinder head off, I mounted the carb and tightened the fixing bolts, aligning the carb to the plate.
With the head off, I could see through the intake clearly - not possible on the bike.
So, the inlet port was greatly improved. I changed the cams to the scrambles type. the piston is 10/1.
Running on a 18 tooth output sprocket, and using a satnav for checking, my top speed was now-
Top gear 60 mph, with difficulty, at 5200 rpm.
Third gear 60 mph more quickly, at 6600 rpm.
The engine did not seem to want to rev any higher. Very disappointing.
I cant think why this could be so?? All the parts seem to be in good order.
Mick