If you are working on the overhaul of a 2 cylinder engine block with the old 1 or 2 pin breather plate, it is advisable to replace it with the later version with cast-in pins
The pins of the early 1 or 2 pin breather plates are known for loosening or breaking off, causing damage to gear case cover.
However, this means that the complete set of gears must be replaced (from 20° to 30° gears)
The breather plate of the newer version is also available with larger slots, reducing pressure in the engine block during the downward movement of the pistons:
useful for engines that tend to leak through the rear flywheel seal
