Cub Cadet 8404 manual When Output Is Insufficient, When Color of Exhaust Is Especially Bad

When Output Is Insufficient

Cause	Countermeasures
Carbon build-up around orifice of	- Clean orifice and needle valve, while being very careful not to damage
nozzle piece	the nozzle orifice.
	- Check nozzle. If defective, replace with new parts.
Compression is insufficient	- Bad valve and excessive wear of rings, pistons, and liners cause
	insufficient compression. Replace with new parts.
	- Grind valves.
Overheating of moving parts	- Check engine lubrication system.
	- Check to see if lube oil filter is working properly.
	- Filter screens or elements deposited with impurities would cause poor
	lubrication. Clean Screens.
	- Check to see if bearing clearances ar within factory specifications.
	- Check engine timing. Adjust timing to 18° before top dead center.
Valve out of adjustment	- Adjust to proper valve clearance:
	Intake — 0.0098 in. (0.25mm)
	Exhaust — 0.0118 in. (0.3mm)
Air cleaner is dirty	- Clean the element and dust cup weekly, and replace element after
	every 100 hours of operation.
Fuel injection pressure is wrong	- Adjust to proper pressure of 2.000 psi (140 kgf/cm2 - 13.7 KPa).
Injection pump wear	- Do not use poor quality fuel because it will cause wear of the the pump.
	Only use No. 2 diesel fuel.
	- Check the fuel injection pump element and delivery valve assembly and
	replace as necessary.

When Color of Exhaust Is Especially Bad

See your Cub Cadet dealer.

Cause	Countermeasures
Fuel governing device is bad	- Contact your dealer for repairs.
Fuel is of extremely poor quality	- Select good quality fuel:
	Above 14°F (-10°C) — No. 2 Diesel fuel
	Below 14°F (-10°C) — No. 1 Diesel fuel
Nozzle is bad	- If necessary, replace with new nozzle.
Combustion is incomplete	- Cause is poor atomization, improper injection timing, etc. because of
	trouble in the injection system, or because of poor valve adjustment,
	compression leakage, poor compression, etc. Check for the cause and
	repair.

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