The clean PTO mounting face ensures customers experience minimal interference from exhaust components for easier installation to their machinery than with some competitive engines.
Variety of PTO Shaft and Mounting Face Options
Silent Semidry Air Filter Types**
Best suited for low dust conditions.
- Water Pumps
- Pressure Washers
- Air Compressors (General Use)
Paper Element + Foam Pre-Filter Types*
Best suited for all dust conditions.
- Air Compressors (Construction)
- Harvesting Machines
- Reel Mowers
- Wheeled Blowers
- Concrete Saws
When starting the engine, the exhaust valve is held open to reduce compression pressure for easier starting.
When starting the engine:
1. The decompression weight pushes the pin up to push the lifter.
2. The exhaust valve is held in the open position, rather than be opened and closed by the camshaft.
When operating the engine:
1. Centrifugal force causes the decompression weight to open, which lowers the pin.
2. With the pin lowered, the exhaust valve operates normally, and is controlled by the camshaft.
A cast iron sleeve is used to increase engine durability and decrease cylinder wear. Due to the difference in expansion rates of aluminum and cast iron, a "Spiny" sleeve design is used to reduce air pockets created by different amounts of expansion. This design also promotes heat transfer from sleeve to block, allowing the cooling fins to work more effectively.
The exhaust valve is manufactured from high-heat-resistant SUH3 steel. The entire valve surface has a polished Tufftride® finish, increasing hardness and decreasing friction through the valve guides. The valve seat is Stellite® coated to increase resistance to the 700+° C valve face temperature exposure.
* Consult Yamaha Motor Corporation, U.S.A. for availability. Available options may require extended lead time for compliance testing when applicable.