Three things worth agreeing in writing
First agree on the code and included components. Second record the stated condition, known defects and inspection results supplied by the seller. Third discuss transport, the inspection window and return terms. An operation video is useful additional evidence, but does not replace a full technical inspection or warranty.
Common questions
Is a video enough to assess an engine?
No. A video does not show every operating condition or internal wear. Ask for available measurements and test conditions; have a specialist assess them.
