Snow Power Series          > Print chart
7HP / SX21 Snow Power
Performance Curve

Engine Overview:

Engine Family Overview:
The Snow Power Series Engines are specifically designed for snowthrower applications. These engines run in sizes from 6 to 9.5 hp with current models starting at 6, 7 and 9.5 hp. The engines are identical to our famous EX Series Overhead Cam industrial engines, with the addition of the cold and snow weather options listed as standard features.

  Class Air-cooled, 4-cycle, Overhead Cam, chain-drive gasoline engine
  Shaft Horizontal
  Cylinders 1
  Displacement 211
  Cycles 4
  Fuel Automotive Unleaded Gasoline
  Max HP/RPM (Gross HP) 7.0/4000
  Max KW/RPM 5.1/4000
  Bore x Stroke mm 67 x 60
  Compression Ratio 8.5 :1
  Starter Recoil & Electric (120V)
  Dry Weight lbs 44.1
  Dry Weight kg 20
  Length inches (mm) 12.8 (324)
  Width inches (mm) 17 (433)
  Height inches (mm) 15 (380)
  Fuel Capicity US Gallons (ltrs) .95
  Fuel Capacity Fl oz (ltrs) (3.6)
  Lube Type Automotive detergent oil (API/SE or higher grade, SAE/5W-30 or 10W-30
  Oil Capicity Fl oz (ltrs) 20.3 (0.6)
  Muffler (type) Rigid Low Tone
  Ignition System Transistorized Magneto
  Lube System Splash
  Color Black
  Governor System Mechanical Flyweight
  Fuel System Carburetor (Primer)
   Key Features & Benefits:
Easy to Use Controls The controls and buttons are large, easy to see and user-friendly.
Snow & Ice Guards These specifically designed snow guards are strategically placed to keep snow and ice from vital controls and linkages.
Snow Power Engine Features These specifically designed features are added for customer  and safety and ease of use.
Carburetor Drain Screw and Translucent Fuel Cup Easy to remove screw for draining the fuel for storage when not in use. Also, a translucent fuel cock strainer cup for inspection and removal of water and dirt particles that might enter the fuel tank and lines.
Specially Designed Recoil & Housing This specially designed recoil housing prevents snow and ice buildup from entering the flywheel and recoil components.
Cast-Iron Cylinder Liner Cast-iron cylinder liners enhance reliability and extend engine life.The cast iron cylinder liner has much better wear characteristics than the softer aluminum that surrounds it, making engine life much longer than if the piston is in contact with the aluminum cylinder wall.
Dual Ball Bearing Crankshaft Support Dual ball bearing crankshaft support offers maximum stability under demanding loads.
Patent-Pending Main Bearing Cover Design An internally structured main bearing cover offers patent-pending technology by creating a highly rigid engine system.
Spheroidal Graphite Cast-Iron Crankshaft The crankshaft is made of spheroidal graphite cast iron, and the crank pin is high-frequency induction hardened. The crank sprocket used to drive the chain, as well as the gear used to drive the governor gear, are pressed on the output end of the shaft.
Timing Chain Oil Lubrication System One of the purposes of the timing chain system is to lubricate the upper portion of the cylinder head. The timing chain is engaged between the sprocket portion of the integrated camshaft in the cylinder head and the crankshaft gear sprocket.
The sprocket teeth in the particular shape they are designed are to enhance the durability and realize low noise level.
High Performance Pent-Roof Design Overhead Cam (OHC) technology and the Pent-Roof combustion chamber allow the Subaru SX engines to use a higher compression ratio of 9:1. The higher compression ratio increases the power produced for a given size engine. It also improves efficiency and overall performance.
High Efficiency Intake Port The illustration shows the straight intake port on the right side of the picture. The lower resistance to the flow of the air/fuel mixture improves the power, efficiency and lowers emissions. Overhead Cam (OHC) technology allows the intake and exhaust valves to be positioned for optimum performance.
Camshaft with Automatic Decompression Release The camshaft and the sprocket are made of special sintered alloy and constructed as a single piece. The camshaft is provided with intake and exhaust cam in one cam lobe. The decompression release lever is mounted on the sprocket end side.
Intake Valve Seal Special machining on cylinder head allows the oil seal to be placed around the valve guide. This seal reduces oil consumption and is replaceable if necessary for service.
Automotive Collets and Forged Steel Valve Retainers Subaru SX engines use automotive-quality collet valve retainers for longer life.
Hardened Steel Rocker Arms Hardened steel rocker arms with precision tappet adjusters are used for greater durability and reduce service requirements.
Special Cooling Fins Cooling fins are cast into both the inside and the outside of the crankcase to utilize every possible cooling area.
Mounting Base Cooling Fins The unique Subaru cooling system extends to the underside of the mounting base. Air is forced over special cooling fins at the bottom of the engine for maximum cooling.
Cylinder Head 360-Degree Cooling Head cooling is critically important to long engine life. The Overhead Cam design allows for 360-degree air flow around both the exhaust and intake valve stem areas.
Patent-Pending Cylinder Cooling Fins Air is forced over the large slanted cooling fins on the cylinder for improved cooling performance. This design is patent-pending.
Patent-Pending Connecting Rod Dipper The SX lubrication system begins with a patent-pending oil scoop to project the oil to the chain.
Aluminum Alloy Die-Cast Connecting Rod The connecting rod is a specially heat-treated aluminum alloy die-casting. Its large and small ends function as bearings. A splasher built into the connecting rod lubricates by splashing engine oil. The piston is an aluminum alloy casting with grooves for mounting compression and oil rings.
Patent-Pending Valve Cover Design A patent-pending rocker cover design constantly supplies an optimum amount of oil to the cam shaft and rocker arm even if the engine is inclined.
Patent-Pending Breather System A patent-pending breather system with a pre-separation
passage prevents oil from spouting even if the engine is inclined.
Ignition System The ignition system is a transistor controlled magneto with the ignition timing set at 23-degrees before top dead center. The magneto consists of a flywheel and ignition coil.
Optimized Capacity-Rigid Type Muffler Optimized-capacity rigid muffler and 33 percent fewer moving valve train parts than OHV designs reduce mechanical noise levels a full 2 decibels below competitive models.
NO Special Tools Needed Even though the SX series of engines bring the latest technology, performance, and durability to the industrial air cooled engine market, there are no special tools required to work on them. Most shop tools that small engine mechanics currently own will also work on these engines for service or complete tear down. Subaru engineers have achieved their commitment to 'keep it simple', while utilizing the latest technology.
Three-Year Limited Warranty Subaru provides a three-year limited warranty. See warranty policy for details.