Carb icing can be a problem under certain weather conditions (generally 25~35 degrees F. and 100 percent humidity).
Carb icing can also be a signal that the carb is running too rich! The more fuel that is converted from the liquid to the gasous state, the more heat required for the conversion.
A very ugly but very effective tool against carb icing is a sheet metal stove on the exhaust with piping of the air to the air intake of the carburetor.
Often, rebuilding the carb will minimize icing; but carb heat is the real answer.
We have experienced LOTS of icing on inline engines (Chevy and Ford sixes, and non-USA fours). The only icing I have ever personally experienced on a Vee engine was a Holley (too rich). The only solution I found was replace with a Carter.
I had one four ice so badly going down the highway that the throttle actually froze in the cruise position. Fortunately, manual trans. When the engine started to die, I tried to pump the throttle and could not; then pushed in the clutch and coasted to the side of the highway. About 2 minutes of very rough running, and the engine heat thawed everything so I could run again. Readjusted the heat stove the next day!
Jon.
