I will check the bottom hose and I sort of knew 160 was cold and 190 was normal (as I had googled it) but it is the way it goes up quickly between 160 and 190+ when revs goes above 2000.
Check the bottom hose by manually operating the throttle on the carb while watching the bottom hose.. When you rev it quickly see if the bottom hose appears to be collapsing.
IF you find this to be the problem you can make a spring for the hose with a wire coat hanger. Simply coil it around a round object that is close to or a tad smaller than the ID of the hose. Stretch it to fit and put it in the hose and reassemble.
