New engines have been inspected to be sure that all parts are present. Dirty engines have been cleaned. All used engines have been test run and adjusted to achieve appropriate high end and idle speeds and smooth transition. All engines have been given a rating according to the following chart.

Rating Description
10 New. The engine has never been run and is expected to be perfect.
9 Bench run only. There may be minor surface scratching, but is otherwise flawless.
8 Flown only a few times. There may be minimal surface wear, but runs without fault.
7 Excellent. Lighter than average use. Will have some oil stains and minor surface wear. Operates at peak performance.
6 Great. Average use but may have a minor issue such as the idle is a couple of hundred rpms above my desired 2,100, or has a broken fin. The issue will be noted.
5 Good. Operating well except for one or two issues that will be noted.
4 Fair. Still runs but will have surface scars (broken fin, enlarged hole, or discoloration) and/or an issue that prevents optimal operation.
3 Poor. Still runs, but has poor compression and/or poor idle and /or problems that makes it unreliable.
2 Parts engine II. All parts are present, but will not run.
1 Parts engine I. Missing some parts.