Sure thing Russ,
Here is what I do when I do pre-purchase surveys for folks.
1. Compression test. Results are 90 psi bare minimum, a good engine would be 110 to 115 psi. (like new is 125 to 130 psi)
2. Drain/check the lower unit and look for signs of water intrusion
3. Check the trim fluid for signs of water intrusion.
4. Start and run the engine and check to see if the charging system works.
5. Water test the boat. This is a must, as there are things that can only be checked while water testing. Now most sellers will not let you drive the boat, and that is normal. But they should allow the boat to be water tested, wether they drive it or somebody else. Never buy a boat you can not water test.
6. While water testing, make sure the engine makes full power under a load.
7. Make sure the trim system maintains the trim angle of the motor while under a load, and does not leak down.
8. After that, just give the boat a good going through. Look for soft spots on the floor. Make sure everything electrical works. Because if you are not handy with electrical, every light and horn will nickel and dime you. Look for any cracking in the transom (indicating a rotten transom)
And that's it, that's what I look for when I do pre purchase surveys. If the boat is near or on the water, it takes about 3 hours to do the average survey of this type. If you can not water test the boat, either do not buy it, or buy it assuming/budgeting for the very worst.
I do want to make sure you are happy with me and my answers before doing the rating. If you have a further question on this, by all means feel free to fire away. If not, please let me know if the ratings box gives you any troubles.
Thanks in advance, and good luck!