Compression and life expectancy

I am looking to purchase a use

I am looking to purchase a used yamaha 200/225.What is the life expectancy for a 1994 225 and what is the should the compression be on this engine.Thanks for any help.

"10 years is getting pretty ol

"10 years is getting pretty old if it has had heavy use in salt water. Then again, many 20 year old motors are still running strong.

Compression is probably one of the best indicators though. I'm not sure for that particular motor, but if it is less than 100, or varies more than 10 between the highest and lowest, then you are probably asking for trouble. Look at general condition (wear & tear, corrosion, evidence of repairs (worn "stripped" bolt heads). Look inside the spark holes with a flashlight - maybe you can see piston damage or groved cylinders. Check gearcase for water or milky color oil."