My tips
- Understand where the motor has been used. Don't necessarily walk away from a salt-water motor, but be diligent in checking ALL moving parts. Tilt pivot, steering, throttle, reverse locking mechanism etc. If any of these are frozen or severely restricted, you can be sure that any future repairs are going to require a lot of extra work (sheared bolts, heli-coils, corroded parts).
- Pop the cover off and look at the cylinder head. If there is any browning/discoloration of the paint, be VERY cautious. If it got hot enough to burn the paint, there is most likely at least scoring in the cylinder(s). Anyone who has gone through the efforts of repairing/rebuilding bores would take the time to repaint it when it's stripped.
- Ask when the last time the water pump was changed (change it after purchase NO MATTER WHAT the answer is). This will help give you an indication of how well the owner kept up with maintenance.
- Ask the owner what the compression is. Check with a gauge when you get there, again regardless of what they tell you. To me probably one of the most important items to check on the motor. Most other items can be repaired fairly easily
- Before running the motor, remove the drain plug from the lower unit (with a rag handy) and check the color/condition of the gear oil. It should be black and pour out evenly. Any unusual bumps in black oil is likely water. If the oil is light tan/creamed coffee color, then there is a fair amount of water mixed in with the oil. Again, this speaks to the maintenance of the motor.
- While running, motor should shift smoothly and quietly. Any shifting noise (especially on muffs) is an indication of a worn dog that will be difficult to engage on the water.
- Lastly gauge the person you're buying it from. No one sells a perfect motor without reason. Did they upgrade? Are they getting out of boating? Why are they selling the motor? When did it last run? Was there a specific incident that caused them to sell it? All questions to help you understand the condition of the motor and what you may face when you get it home.
Good luck!