I guess it depends on what you're expecting from it and what price he's asking. That looks like an older motor that has definitely seen time in salt, but from the short video it appears to at least start OK and wasn't smoking. It is not possible to tell from such a short clip if the carburetor is going to need cleaning, which is not major but is an expense if you're not going to do it yourself. If the price is right then why not, but keep in mind that corrosion is what kills most motors. For example, water pump impellers, thermostats, engine and lower unit oil and valve adjustments are regular maintenance items on any motor, but if those bolts haven't been removed in a long time then what should be a 20 minute job can become much more involved. I would personally pass and look for a fresh water motor, unless the price was super good, but I'm picky. What price is he asking?
Edit --> I'm revising my answer after re-looking at the pictures. It's not terrible, I bet it would clean up nice. My only concern would be internal corrosion.
Thanks! He wants $400 for the motor. And optionally +$100 for the 6hp kit (carb + prop... Although it seems I could buy each of those individually for around $30-40 off ebay and save some money if I really wanted those)
BTW, suggestions/feedback someone else on another forum:
"The 'real' test is using a compression gauge and putting it in place of the spark plug. However, you don't really need that. If you just pull the handle slowly then you should feel the cylinder going into compression every other revolution. Those engines have a compression-reduction mechanism that lowers the compression for pull-starting, so you'd only measure like 60PSI when pull starting, but you should definitely feel it every other revolution. The low reading on the compression tester makes some folks think that it doesn't have the right compression (which would be over 125PSI).
Keeping the carbs clean is important on these motors. I'd bet the original one is plugged up and that's why he bought the 6HP carb to replace it. If that's the case, offer him $75 for the carb and put it on (just two screws and some linkage). Never let the motor sit for a long time with gas in the carb. If you might not be using it for more than a week or so, make sure you just run the motor until the carb runs out of gas. (switch off the fuel valve or disconnect the external tank first). The other thing you want to make sure you DON'T overfill the oil. The level should be BELOW the "full" mark on the dipstick, NEVER AT OR ABOVE. If there's too much oil it will start to foam up and trigger the "low oil pressure" switch which will cut off the ignition.
When/if you get it then change the oil immediately so you have known "good" oil in it. It only take a portion of a quart. Also change the lower unit fluid and make sure there's no water in it. If there is any water, then run it for a bit and change it again. If there's still water in it you might have to change the prop seals but that's not a really big deal to fix. If there's very little water you can just keep changing the lower fluid until you get a chance to fix the seal.
ALSO, just looked at that video and there's not enough water in that tank so it's likely the impeller was running dry. Can't tell if the engine was 'peeing' or not, but the water should be ABOVE the ventilation plate to make sure the water pump has enough water. The impellers are very easy to change too... the toughest part is getting the shift linkage re-aligned when putting the lower unit back up into the motor. There's some youtubes on this to watch. The impeller are cheap too (you can buy them for about $12 and should always have a spare)."
