1901-1953 Indian Motorcycle – Parts – Accessories

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  5. 92 – Junior Scout Pistons And Heads


In order to have the efficiency as high as possible in this little motor, the compression ratio has been raised and in doing so, the piston heads came flush with the top of the cylinder, leaving the thickness of the gasket between piston head and cylinder head, for carbon space. Oftentimes in breaking in these motors at slower speeds, carbon will form on top of the piston and on the cylinder head, building up to the extent of where piston head will hit the cylinder head. When this happens, there will be a noticeable knock in one or both cylinders. This makes it necessary to remove the
cylinder heads and clean the carbon out, and the knock will disappear.

Erle Armstrong
Service Engineer

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