What’s the purpose of the throttle and the gears on a snow blower

better than metal flashing and its excellent ability to repel water/moisture is self-sticking rubberized flashing. Although 15 pound roof felt also is acceptable. Either product should be lapped over by the (if any) house wrap and fastened with minimal nails ,etc. I'm not sure about the problem you have in regards to re-installing the clapboards? Won't they re-install with the original fasteners? or is there concern about nailing through the metal flashing?

My Craftsman 3/21 single-stage, 2-stoke snow-blower now works perfectly and discharges snow from chute as expected/desired. Thanks to everyone that helped me solve this HI/DIY problem!!!

Corrective steps toward problem-resolution:

1. Replaced drive-belt (specification was 35"; my old one had stretched out by over an inch)
2. Replaced auger-blades (hard rubber) with new ones. The old ones were worn-out and were not (almost) sweeping past the backboard near the chute. The recommended gap is less than 1/4 inch. My old blade had a gap of almost 3/4 inch
3. Sprayed snow/ice repellent near the neck of the chute to prevent ice build-up when dealing with wet-snow (as was the case today in Chicago).

BTW, I took this DIY opportunity to replace all screws & aluminum rivets with appropriate stainless steel nuts/bolts/washers. It costed me an additional $6; however, I thought that it will save me a lot of time when it comes time to do maintenance on my snowblower some time in the future ... especially since the screws get rusted quickly as snowblowers are mostly/often used in wet conditions and we (at least I) often do not take the time/trouble of wiping the snow-blower after using it (since it is too cold outside).