About what should compression be?

[54Hornet]

Hello,
I am going to look at a boat I am thinking of buying.
It has a 2004 130 HP 2-stroke Yamaha. The meter says 120 hours on it.

I am going to see it run, and the owner; who is a marine mechanic, is going to do a compression test on it so I can see what the numbers are.

My questions are,, what should those numbers be?
( I have heard as long as they all are within 10 of each other it's good. )

Anything else I should be looking for or asking about?

Input appreciated.

[rodbolt17]

whithin 10 PSI and all is good.
may wish to check the gearcase oil.

[YammyMan]

And if I can throw my 2 cents worth in. Make sure he opens the trottle to full open when conducting the compression check. This can make a difference in readings. Good luck.