Well, I had that problem with my 40, I've never run a hood in 35yr's. Wife and I had gone to a get together a few years ago in the fall, on the way home it got real cold and started to spit snow. About 35 miles from home on the pike going about 65, I let my foot off the gas and the pedel and it stuck. With the hood off I could see the carb on top of my McCollet Super Charger, The frost was all around the bottom of the carb, SO I kept going and the engine started slowing down, when I got off the exit about one mile from home I was down to 20mph, I rolled into my yard, pushed the button for the garage door to open, drove in the garage, left the engine running, got out and watched the engine running, it kept speeding up, I had to run around and turn the key off. The carb had iced up and the throttle bore was only about big my little pinky. No heat riser to the carbs on top of a Super Charger. Walt