MVC,
The gear start mower does operate on a lower rpm compared to the power torque engine. In order to slow the rpm's on the power torque engine you would need to check the spring under the primer cap as they have three different colour types.
Also you can use brass shim's to slow the rpm's down on the power torque engine, which go in the carburettor.
We have detailed information in the parts list and manuals area of the forum.
