If you are looking for a marine repair manual you probably have some mechanical skill but not so much you want to completely rebuild right down to the crankshaft. This book does the exact opposite. Wasted pages on the basics of four cylce combustion (who is there that would not already know but still care?), chapters on using micometers on everything from pistons to bearings (something usually only done in rebuild shops). But there is very little information the average boat owner can use. Little or incorrect information on replacing risers, pumps or stern drive removal.The Seloc manual is a much better choice although it has many of the same sins, just less so. The Seloc also has much more complete tune up information. The factory manuals have better illustrations than either manual but are harder to find.