| A. | Wiseco Powersports pistons are designed for optimal piston to wall clearance for the specific bore size of your engine. For example, your 125cc dirt bike engine is 54mm bore, the Wiseco piston is designed just for that bore size, and does not require any specific adjustments to fit properly. Some applications, such as higher stressed race engines (or nitrous injected), forced induction engines (supercharged or turbos), do require additional piston to wall clearance than Wiseco has designed into the part. These are special applications that are normally built at high performance engine shops. These builders are familiar with the needs of these engines, and can help establish the needed engine set up parameters including piston to wall clearance. As a general rule, any high stress engines that include nitrous, turbo or supercharging, up to high pressure blowers require an additional .001 to .003" clearance. |
| A. | Outboard engines are very unique, in that the cooling system uses cold water from the lake or ocean. Because of this, the engine cylinder runs very cool as compared to many other engine types, and the piston does require more clearance to operate properly. Your Wiseco piston does have this additional clearance built into the design, and it is always best to follow the proper break in process. This is an extended process of heat cycling of the engine, and will ensure an extended piston life when followed. Refer to your OEM service manual for the proper break in for your engine, or you can also refer to our Marine catalog for general guidelines. Unquote |
