Cub Cadet T65 Series - Manual (Page 23)

Basic Troubleshooting
17
Identify factors that could cause the problem
This is the second step in the troubleshooting process.
1. Crankshaft will not turn.
A. Starter not working. This can be an electrical failure or a mechanical failure. The likely suspects are:
I. A dead battery.
II. A bad ground.
III. A failure in the electrical circuit.
IV. A failure of the starter itself.
B. Engine in a bind (external - attachment jammed). This usually indicates that the unit being powered by
the engine either failed or has something jammed in it, locking up the system.
C. Engine in a bind (internal - engine seized). This is usually either a quick fix or a catastrophic failure. The
likely suspects are:
I. Complete hydraulic lock (easy fix).
II. Bent crankshaft.
III. Internal binding, crankshaft, connecting rod or piston.
2. Crankshaft turns, no start.
2a. Most gasoline engine diagnosis involves isolating problems in the four critical factors an engine needs to
run properly:
I. Ignition- sufficient spark to start combustion in the cylinder, occurring at the right time.
II. Compression- enough pressure in the cylinder to convert combustion into kinetic motion. It also
needs sufficient sealing to generate the vacuum needed to draw in and atomize the next intake
charge.
III. Fuel- correct type and grade of fresh gasoline; in sufficient quantity, atomized (tiny droplets) and in
correct fuel/air proportions.
IV. Flow- if all of the above conditions are met but the flow of air is constricted on the inlet or exhaust
side, it will cause the engine to run poorly or not at all. This also includes ensuring the valves are
timed to open at the proper time.
2a. Isolate the ignition system and compression from the fuel system by preforming a prime test.
I. Burns prime and dies. This would indicate a fuel system issue.
II. Does not burn prime. Not a fuel system issue. Check for an ignition, compression or flow problem.
2c. Compression or ignition problem.
I. Check the engine stop and safety switch.
II. Test the ignition system using a proper tester.
III. Replace the spark plug with a new one or a known good one.
IV. Check compression or leak down.
V. Check valve lash.
VI. Check valve timing/actuation.
VII. Check exhaust.
3. Starts, runs poorly.
3a. Starts, then dies.