15-01-13, 07:17 PM
For what it's worth, carburettor icing requires humidity to take place so in very cold conditions it's unlikely happen as the air is too dry.
I've found that between 2ºC and 6ºC is ideal to trigger icing on a Fazer with blocked carb heater pipes, the jets themselves ice up as the evaporating fuel cools the damp incoming air to below freezing. The bike gets gutless a couple of miles after starting off and then dies, about two minutes later you thumb the starter and it's like nothing was ever wrong as the warmth from the engine has now reached the carbs and it stays fine for the rest of the journey. Quite puzzling the first time you come across it!
It lead to some scary moments on my old Honda 125. Rather than having a butterfly valve the throttle cable on that simply pulled the carburettor slide and needle up against a fairly weak return spring. When you got icing conditions the tapered needle would jam progressively higher each time the control was moved until the engine was running nearly flat out. I'd kill the engine and then, finding nothing obvious wrong, try to kickstart the bastard thing back into life. Once I'd worked up a good sweat in my bulky oversuit the residual engine warmth would reach the carb and it would run perfectly normally. Thought I was going mad until my dad told me about carb icing. :lol
I've found that between 2ºC and 6ºC is ideal to trigger icing on a Fazer with blocked carb heater pipes, the jets themselves ice up as the evaporating fuel cools the damp incoming air to below freezing. The bike gets gutless a couple of miles after starting off and then dies, about two minutes later you thumb the starter and it's like nothing was ever wrong as the warmth from the engine has now reached the carbs and it stays fine for the rest of the journey. Quite puzzling the first time you come across it!
It lead to some scary moments on my old Honda 125. Rather than having a butterfly valve the throttle cable on that simply pulled the carburettor slide and needle up against a fairly weak return spring. When you got icing conditions the tapered needle would jam progressively higher each time the control was moved until the engine was running nearly flat out. I'd kill the engine and then, finding nothing obvious wrong, try to kickstart the bastard thing back into life. Once I'd worked up a good sweat in my bulky oversuit the residual engine warmth would reach the carb and it would run perfectly normally. Thought I was going mad until my dad told me about carb icing. :lol