The inlet port diameter on my 1930 Model 9 single port is 1" and is fitted with a 1" Amal 276 (from a Norton 16H WD) which is wrong for the bike. According to the books the correct carb is an Amal 29/001 but this is 1 3/32" diameter which is obviously too big for the tract diameter. Can any one shed some light.
John D
Hi John
You have probably sorted out the mystery by now but I thought I would reply. I have a 1930 model 9 and it was originally fitted with an Amac carb and the inlet port is 1.125 dia. My carb was pretty well worn so I have now fitted a brand new one purchased from http://amalcarb.co.uk/pre-monobloc.html This has a slightly bigger inlet bore, but I made a sleeve to bring it down to 1.125.
Graham