Coolant hoses on Carburator

[Jules-C]

My poor explanation trying to cut down length of post.  Carb icing would start to affect low speed running about half a mile after starting in sub zero or very close to zero conditions. It would slowly get worse for the next mile or two until it got to the point when the bike would cut out whenever the revs fell below 4 to 5 thousand rpm. Great fun trying to drive on icy roads in first gear with 6k revs and every boy racer trying to race you because your sitting at the lights revving the engine.  That's when you find out if you turn engine off when you pull up at lights when you start it again the problem has gone. 

Cleared out the carb heater tubes and problem never once reoccurred.  If you got an explanation that doesn't involve pilot jet icing I'd like to hear it.