I am considering purchasing a 1986 Yamaha 9.9 4 stroke outboard with a 25" shaft. Motor is in good condition, and the price is $400. I do not know anything about the Yamahas, but is this something I should consider?
Yamaha outboards are well made and should be a good investment if indeed it is in good working order. A few things to consider when purchasing an outboard is that although 4 stroke engines are quieter and more fuel efficient, they are more complex internally and can be much more expensive to repair. I would be wary of any outboard that was run in salt water conditions and did not receive regular maintanence. Check to see if the owner did his own maintanence or if he had it winterized by a marina. Before purchasing it, see if the seller will let you bring it to a reliable mechanic and let him evaluate it for you. Little things like low compression or milky looking lower end oil can spell a big repair bill that can easily exceed the purchase price.
While Yamaha builds great outboards,(4 in my family) the 9.9 4 stroke (somewhere in the vintage you''re considering) turned out to be very unreliable for my brother. Used as a troll motor on his Mako it bit the dust after raw fuel entered the crank case. Very low hours, very un-Yamaha like. He likes his 150, any of the small 2 strokes are great as auxilliaries. I''m selling my 22'' sailboat but keeping my 8hp Yam. I''ll put my Merc 3 on it and let someone else deal with that noisy junk.