I have an older Murray snowblower with a 5 hp tecumseh motor on it, It starts and runs pretty good for being 26 years old. Last time I used it it seemed like at top speed it was kinda weak and struggling to throw snow, and move itself through the snow. I went online and bought one of those cheap small engine tachs to see what top RPM is. Idle is about 1150-1200 rpms with the tach, and top RPM only goes to 1900-2000 according to the tack. I don't have another one to check it against, but to me that sounds like why it isn't throwing snow as good as it could be. I can move the throttle lever by hand on the carb, and the rpms will go up to 2500-2600 rpms. Sounds like its making more power at that rpm, but I can't get it to go that high with the throttle lever on the machine. Any experts want to take a shot at what's wrong with it?.,,,