Wiseco forged piston for GasGas EC 250 21-24 (piston diameter 66.33mm)

WARNING: The DIAMETER measure indicated above in the specification:

-If the product code (see it on top under the product title) ends wich a letter (A, B, C) the indicator diameter revers to the piston size.
-If the product code dose not end with a letter, then the diameter indicates it revers to the size of the cylinder bore where pistone will be installed.


The price is for 1 Piston complete with ring/s, pin and clips photo is generic.

Assembly must only be carried out by professional staff, following the motorcycle manufacturer's instructions and in any case after checking the adaptability and correct compression ratio BEFORE installation.

The WISECO pistons, built in U.S.A., are produced by forging, do not have centesimal increases and their indicated size is the nominal one (i.e. referred to the nominal size of the cylinder). This particular feature is a typical feature of Wiseco pistons, developed and used in its 70 years of production.

In fact, Wiseco forged pistons have a different, but calculated, expansion compared to any other competing product that allows you to profitably use a single size in a new or moderately worn cylinder. This is possible thanks to the uniqueness of the characteristics of the aluminum alloy used, the advanced study of the expansion, therefore of the thicknesses in each precise point of the piston and the particular forging system.

In fact, for Wiseco, using a size A - B - C piston on a cylinder that is too worn or oval is just a palliative, moreover, too precise A - B - C size couplings are often used which, by increasing friction, actually reduce engine performance. . Wiseco pistons have proven over time as the best compromise between durability and performance.

Wiseco leads the performance aftermarket by producing the highest quality forged pistons for Dirt Bikes, ATV's, Snowmobiles, Outboard Marine, and Motorcycles right here in the USA. Wiseco is unique because we forge all of our own pistons in house, and produce all of our own forge tooling right here in the USA. This allows us to control all aspects of our manufacturing process from raw bar to skirt coating finished parts. 

In addition, in-house dyno testing gives Wiseco the ability to develop state-of-the-art technology such as new shapes, coatings, and components, and lead the industry through rigorous R&D. Linking all segments of Wiseco’s organization through design, testing, manufacturing, and distribution allows us to fulfill market needs with minimum lead-times. 

Extreme racing conditions demand the strength and toughness that only forged pistons can offer. Compared to cast pistons, forgings are tougher and more durable, and will stand up to the abuse that high performance motorsport applications require. Most castings are brittle, have no grain structure and tend to fail catastrophically when the material yield strength is exceeded. Forgings have condensed grain that is aligned to the features of the part, which produces higher mechanical properties, and resistance to impact and fatigue. Each forging is designed to optimize the strength-to-weight ratio, and maximize performance.

Wiseco’s detailed skirt shapes and profiles are very specific to each application. Variable cam programming software developed in house allows Wiseco to produce high-performance shapes unique to only Wiseco. The skirt shape (barrel/cam) is one of the most functional areas on the piston, and provides stability and smooth operation in the cylinder bore. Stability is important for proper ring seal, reduced friction, and quiet operation. Each skirt shape is designed for a specific running clearance, based on coefficient of thermal expansion of the piston alloy. Some forging alloys expand more than casting alloys, but each Wiseco piston is designed with the proper installed clearance to produce the most power, least wear, and best seal at running temperature, for each application. Comparing installed clearances on cast vs forged parts is not indicative of the running clearance at temperature. Wiseco engineers have a strong background in all forms of racing applications, and produce the best shapes and designs in the industry. 

Some of forged pistons offer new ArmorGlide™ skirt coating, which is the result of testing, development, and benchmarking through Wiseco’s rigorous in-house dyno program. The outcome is the ultimate in skirt coating toughness, lubrication, and bond technology working together to minimize friction, maximize horsepower, and provide improved wear resistance. Not only is ArmorGlide™ a high-tech lubricant that reduces friction, but it also allows the piston to be fitted tighter within the bore allowing a better ring seal and reduced noise from piston rock.