Eric A. Jones
|Lawnmower Repair . Certified Master Service Technician from B&S. Have 23 years experience on B&S, Lawn Chief, Weed Eater, Echo, Peerless, Wheel Horse, Snapper, Atlas, MTD, McCulloch, Homelite and many other numerous brands. Specialize in electrical repair.|
Here is a link to the service manual: http://www.mymowerparts.com/pdf/Tecumseh-Service-and-Repair-Manuals/TECUMSEH-SER See
There could have been a sticker, metal tag or the model tiller model may have been painted on the handle or other metal tiller part. Sometimes age and rust will cause the paint to fade or the sticker
The best method to tell how much horsepower an exhaust system helps produce is to use a dynamometer (dyno) to measure the engine output. It will be very difficult to accurately measure the engine output
Most likely the high carburetor high speed circuit is still blocked by something. Some of those twin carbs can be pretty sensitive. Did you dis-assemble the fuel pump and check the diaphragms and springs?
Is the fuel pump part of the carburetor or is there a separate fuel pump mounted to the engine? Eric