I have a 2012 Pro Drive w/the 36 HP Vanguard on it, and I recently noticed that the carb will ice up at temps below or near freezing, which causes the engine to run erratically, and it will absolutely not idle. I have discussed this w/many experts, and they have said that this is rarely seen, and typically only happens when temps drop from above freezing to below freezing quickly. They advised me to turn the breather cover intake down, instead of to the side, like it comes from the factory to allow the warm air from the exhaust to flow through the breather instead of the cold air. I am puzzled because my carb is freezing, and nobody else that I talk to at the lakes/bayous are having the same problem, and most of the shallow drive rigs I see run the same engine. We've ruled out the possibility of water in the fuel, and I hate to install a cold weather kit, considering temps typically get above 40 degrees during the day around here, and they say I'd have to remove it at temps above 40 degrees. I asked the mechanic that's working on it to see if he sees any leaks on the intake, and that's where I stand so far. Does anybody have any advice? Thanks

Lots of threads on this...here is a recent one:
viewtopic.php?p=407041#p407041

Try using google for threads older than august, and start the search with: site:mudmotortalk.com then enter your keywords

You shouldn't be icing up here in N. Texas- you sure thats it? Taking warm air off the muffler should be fine for this area.

You can get carb icing with the air temp in the mid 40's F and high himidity. What I see is a drop in over all rpm's and bogging down of the motor and puffs of black smoke out the muffler. Turn your air intake housing around so it will pick up the warmer air. Should smooth out and pick up RPM's again and any black smoke out the exaust should disappear. You will loose maybe 100 RPM's at top end but it should run fine. Duckdon

If your engine is running extremely lean it could be a factor... Check the plugs to see if there white on the tips, if so your engine is running lean, could be the jetting on your carb. Cold dense air needs more fuel to run properly. The icing may not be the problem but the effect of a different problem, make sure you are getting proper fuel amount to the carb. Might be totally wrong but it's worth a check...

40s are causing carb freezing? ?

Is it a humidity thing?

I run a 27 prodrive in Canada and at -17F it still runs great...
Hard to start mind you but runs great