The Briggs & Stratton 135202 engine is a single-cylinder, low-emission, gasoline-powered, air-cooled engine. This is a popular workhorse engine that can be found on everything from leaf blowers to go carts. It's a horizontal shaft engine which uses a rope handle starter. Electric starters were available as an option. This engine has been discontinued.
This engine has a bore size, or the internal diameter of the cylinder, of 2 9/16 inches, or 65.09 mm. The stroke, or the up-and-down distance the piston travels, is 2 7/16 inches, or 61.91 mm. The displacement, which is the volume displaced by the piston when it travels a single movement from top to bottom, is 2.57 inches, or 206 cc. All three of these measurements, plus the number of revolutions per minute, are required to calculate the exact horsepower. The manufacturer rates this engine at 5 hp. As with all internal combustion gasoline engines, the actual horsepower produced will decrease with increases in altitude and temperature. The 135202 engine will provide a solid 5 hp for your application or use.
Briggs & Stratton recommends that the air gap setting for the armature be set at 0.010-0.014 inches, or 0.25-0.36 mm; the spark plug gap should be set at 0.030 inches, or 0.76 mm. Valve clearance, with valve springs installed and piston 1/4-inch or 6 mm past top dead center, is intake valve set at 0.005-05007 inches, or 0.13 - 0.18 mm, and exhaust valve set at 0.009-0.011 inches, or 0.23-0.28 mm. Make sure that the engine is cold when you measure the valve clearance. Briggs & Stratton sells a "Spark Tester," part number 19368, to check for spark.
The model 135202 engine holds 2/3 quarts, 21 ounces, or 0.6 liters of oil. The manufacturer recommends the use of 30-weight detergent oil. Do not use special additives, as air-cooled engines run hotter than car engines. Keep the oil level at "FULL" and check it every eight hours of engine operation.
This engine uses regular unleaded gasoline with a minimum of 77 octane. This is a four-stroke engine, and you do not mix oil with the gasoline. The manufacturer warns against using Methanol. Do not fill the tank higher than 1/2 inch below the fill opening, as the fuel will expand.
Check the oil level every eight hours or daily. Service the air cleaner every 25 hours, or every session if you are operating in a very dusty environment. Change the oil and inspect the spark arrester, if so equipped, every 50 hours. And finally, replace the spark plug every 100 hours of operation. These are manufacturer recommendations, but if you are using this engine in an adverse environment you should perform maintenance more often as that environment dictates.
Frank Gates started writing technical documents in 1980 as part of his telecommunications job. He is now a full-time technical writer. Gates has published two books, "Motorcycle Rider Basics" and "The Absolute Supervisor." He earned a technical diploma in electronic communications from the DeVry Institute of Technology.