Here in Indiana the temperatures drop pretty low in the winter.
We have had some 15 dF mornings so far.
Our Carbon Cubs don't like to start at anything below freezing unless they are heated.
To help solve the problem I built a heater.
This is the unit I purchased from Ace Hardware for $20
I popped the handles off the front and added an aluminun right angle vent adaptor from Home Depot to the front with sheet metal screws.
A dryer vent hose and a plywood base to keep it from tipping completed the unit. Total cost -- less than $40.
I added a movers blanket from Harbor Freight for $7.99 on sale.
This keeps the engine warm to the touch on the lowest (750Watts) setting.
Works great!
Bill
PS - nothing gets very hot . You can lay your hand on the bottom surfaces.
When It gets really cold I will use the 1500 Watt setting.