31-07-2019, 09:43 PM
Carb icing?
Could we, just possibly, be barking up the wrong tree here? Probably not, but the other day, when it was both hot and humid and the engine would not take full thottle and misfired. I stopped to check - the SU carb on my Chummy has no hot spot (4-branch exhaust) and around the area of the venturi was ice cold with copious amounts of condensed water. The float bowl was warm, but not hot. Now, as I was once assured by a flight instructor telling me about induction icing problems, "It's always winter inside a carb" - and even at temperatures exceeding 30 deg C on humid days the drop in temperature between inlet and venturi can lead to icing. So, when it stops raining, I'm going to try the 1% to 2% recommended of this: https://www.amazon.co.uk/gp/product/B006...UTF8&psc=1
Incidently, many pilots have lost the plot when, suffering from icing, they've switched to hot air and despaired as the engine ran even more roughly as the ice melted. In a panic they turn hot air off, only for the engine to stop and refuse to restart. At least we can park at the side of the road....
Could we, just possibly, be barking up the wrong tree here? Probably not, but the other day, when it was both hot and humid and the engine would not take full thottle and misfired. I stopped to check - the SU carb on my Chummy has no hot spot (4-branch exhaust) and around the area of the venturi was ice cold with copious amounts of condensed water. The float bowl was warm, but not hot. Now, as I was once assured by a flight instructor telling me about induction icing problems, "It's always winter inside a carb" - and even at temperatures exceeding 30 deg C on humid days the drop in temperature between inlet and venturi can lead to icing. So, when it stops raining, I'm going to try the 1% to 2% recommended of this: https://www.amazon.co.uk/gp/product/B006...UTF8&psc=1
Incidently, many pilots have lost the plot when, suffering from icing, they've switched to hot air and despaired as the engine ran even more roughly as the ice melted. In a panic they turn hot air off, only for the engine to stop and refuse to restart. At least we can park at the side of the road....