How to buy used motorcycle engine?

[tomahawk_juan]

I am attempting to purchase a motor for my younger brother who knows his way around motorcycles, unlike me. In an attempt to surprise him, I went ahead and found a used 78 CB550. What and how must I check that it is a decent engine (a motor that requires some work will do, a seized engine will not). I realize that it may be difficult to tell, but are there ways of checking that a motor is in decent condition?? Thanks in advance.
T_J

 

[DesmoBro]

take a battery car/motorcycle, Jumper cables.....Hook up the battery to the jumpers, hook the negative on the motor anywhere then the positive on the starter....the starter should turn the motor over if it's not seized and the starter isn't fried....also make sure the battery you use isnt hooked up to the bike

I should also mention that when you touch the positive to the starter it should be where the wire hooks up to it