Wrist Pin Engine Diagram. Be careful to order the required quantity when adding a part to your cart. The piston wrist pin is re quired to handle the extreme thermal load and cylinder pressure of the engine while staying rigid and minimizing any expansion or flex.
Metallic piston wrist pin and connecting rod which normally do not fit together can be joined with one selected component being heated to effect the expansion thereof while another selected component is chilled to effect its contraction. Complete engine diagram for the 139qmb 49cc scooter engine. Select the required part number in the diagram or refer to the list above to find the information and prices relating to the different parts.
A spring loaded lock on each side that secures the pin between the pin bosses this can be a spirolock circlip round wire lock etc.
This wrist pin measures 10mm in diameter and fits 2 6680cc 2 cycle engine pistons. And since the produc tion of horsepower creates both cylinder pressure and heat the piston pin is an essential element in an engine program and needs to be designed for the ap plication. Caution both piston pin plugs in a cylinder must be of the same part numbers and must be replaced in accordance with figures 1 2 and 3 and the instructions listed below. This wrist pin carries the full force of combustion.