Outdoor Power Equipment and Small Engines - repowered old craftsman snowblower

I have repowered an old gear drive craftsman snowblower and now it will not throw snow well? It had a 7 hp Tecumseh that did not run. The blower is close to 30 years old but in great shape. I put a 9 hp Tecumseh snow king on it, but now think the max rpm may be lower on the new motor. The centrifugal clutch has 12 teeth and the auger shaft has a 40 tooth gear. I have ordered a 30 tooth gear to try increasing the speed of the auger but cant go any smaller than that. I dont know if this will help much, any ideas?

have you checked the max rpm ? the sprocket might work but you'll be lugging the motor if it's not up to spec.

i can not find the max rpm anywhere, i think it is lower than the old engine. i have been told that the old engines are 3600rpm and the new ones are 1700rpm.

What part number is the new motor, 1700rpm sounds low.

Max RPM on new engines is the same as the old engines. 3500-3900 RPM. If your engine is not runningthat fast, you have a problem with the engine.

your machine was designed to run at a specific rpm. 1700 is not an operating rpm for a gasoline engine as it is not within the powerband of either a four stroke or two stroke engine.
proper engine speed for cooling is another issue.