Well i can start you off with the Code, 890622 would be 22 Jun 1989 from what i know, there are others here that will be able to say more, I'm pretty sure your looking at 28 Cubic Inches (about 458.8cc)

The date of the engine would put it most likeley on an 89 mower i would say, or possibly early 1990, depending on how long beween the buld of the engine, and when it was put on the mower.

Cheers
Ty

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