Solution Number: 72247

Solution Summary: CNG Ignition System Component Maintenance Instructions and the only recommended
Spark Plugs for HFNO1, HFN0O2, HFNO3, HFNO4

Publication Date: May 28 2013

**Paner copies of solutions may not be the most current solutions**

Complaint or Symptom :

How do | properly install plugs and wires on my CNG engine?

Engine misfire performance symptoms and carbon tracking of ignition components.
Problem or Situation :

Lean burn high energy ignition systems must be properly maintained to achieve optimum performance and reliability.
Poor installation techniques and/or faulty components will lead to engine performance issues. It is imperative that all
components be installed properly, be of proper quality, ensure component cleanliness, and ensure cleanliness during the
complete installation process to ensure high performance.

’
ar

Solution ;

VE

REMOVE AND INSTALL SPARK PLUGS & WIRES

CAUTION: Electrical shock may occur if you come in contact with live electrical components. Disconnect power —
before servicing ignition system.

IMPORTANT: Avoid damage to spark plug boots by pulling straight out on boots when removing. Never remove wire
assembly by pulling on wire directly as it may result in separation of wire from boot.

1, On HFNO1, HFNO2, and HFNO3 Engines: Remove ignition coil. Remove spark plug boot using JDG815 Spark Plug
Boot Pliers if necessary.

2, On HFN04 Engines: Remove Spark Plug Boot from spark plug. Remove spark plug boot using JDG815 Spark Ping
Boot Pliers if necessary.
3, Check plug bore for water and/or debris. If present, use compressed air to remove. CAUTION: Use eye protection if
compressed air is used to clean spark plug bores. cas

4. Loosen spark plug approximately 1/8 — 1/4 turn, use compressed air to remove any debris dislodged, turn plug back in
a bit to allow any carbon on the threads to dislodge, then remove plug. If plug show hesitancy in removal, turn back in
several times to dislodge any carbon that may be on the end of the threads.

5. Remove spark plug. Take extra care as to ensure socket is properly attached as to not break the spark plug during this
step. bic:

6. Inspect spark plug mating surface on cylinder head to make sure surface does not contain debris or corrosion. Clean as
necessary to ensure proper spark plug firing sealing ring to cylinder head surface mating. ee

bj

7. Inspect cylinder head spark plug threads to make sure no damage is evident.

8/8/2914
8. Check spark plug. (See CLEANING AND ADJUSTING SPARK PLUG GAP in this group). Replace as necessary
according to guidelines. NOTE: Use of anti-seize or other thread treatments is not recommended.

9. Install new spark plugs RE5S33709 (only use this part number) and tighten to specification using clean magnetic
socket.as to not further contaminate clean spark plug. 72247 _L.jpg

Spark Plug Torque = 38 Nm (28 lb-ft + or — 2 lb-ft)

IMPORTANT: Do not over-tighten spark plugs.

10.,Inspect spark plug boots for damage and replace as necessary. Always replace spark plug wire(s) if flashover or
carbon tracking as noted in the CLEANING AND ADJUSTING SPARK PLUG GAP group is present. Spark plug
wires/boots should be replaced at every other spark plug change according to the maintenance intervals outlined in the

Operater’s Manual.

11. Clean the inside of the spark plug wire boot and coil side wire connector boot/terminal with rubbing alcohol to
remove any residue. oil. or debris.

12 Apply a small amount of silicon dielectric grease on the outside of the rubber boot where the outer boot surface
interfaves with the cylinder head to aid in proper boot seating. IMPORTANT: Wire and metal terminals should be
free of dielectric grease at all times. Dielectric grease on electrical connections may result in weak or misfiring
cylinders. Periodic cleaning and careful installation will prevent grease from contacting the ignition terminals.

13. Install the wire onto the spark plug making sure that wire is fully clamped to spark plug terminal. A “clicking” sound
and.teél will be evident when wire 1s properly connected to spark plug.

14. On HFNO1, HFNO2, and HFNO3 Engines: Install ignition coil.
15. Connect remaining wire end to coil

WARNING: Use of non-John Deere ignition components are not recommended and may result in engine damage
and/or void engine warranty.

CLEANING AND ADJUSTING SPARK PLUG GAP

1. Remove spark plug(s). (See REMOVE AND INSTALL SPARK PLUGS & WIRES in this group.)

2. Clean spark plug threads by hand with brush and isopropyl! alcohol if used spark plug being proposed for reinstallation.
If a wire brush is used, care must be taken to ensure that wire brush does not come in contact with the spark plug’s
insulator core nose.

3. Clean any deposits from electrode and insulator area on used plug if needed. Use of a wire brush is not recommended
on the firing end of a spark plug as it could lay down a conductive path on the insulator core nose.

4. Inspect insulator and electrodes for the following conditions: * Eroded Electrode * Flashover on Insulator * Ground
Electrode and Center Electrode Surfaces Not Parallel.

5. Replace spark plug if any of the above conditions are evident.
6. Check spark plug gap and adjust gap to specifications if needed.
NOTE: Only bend negative electrode strap. do not pry against small center electrode, (damage will occur).

Spark Plug Gap = 0.38 mm (0.015 in)

8/8/2014
* A pin gage is recommended by the plug supplier for improved accuracy.

7. Check spark plug resistance by placing multi-meter to end of clamp terminal and the center electrode. Replace plwg if
not within acceptable resistance range.

Low voltage test acceptable resistance range 5 - 18 kOhm new plug 5 — 25 kOhm used plug, High voltage test acceptable
resistance range 5 - 15 kOhm new plug 5 — 18 kOhm used plug ote

8. Clean the upper portion of the spark plug hex, ceramic body, and wire terminal with rubbing alcohol.

9. Apply ginall amount of dielectric grease around base of ceramic body no higher than the convoluted section of the
ceramic. This will allow better boot seal and less boot to plug resistance during installation. Be sure to use dielectric
grease very sparingly.

10. Install spark plug into cylinder head using care as to not disturb dielectric grease and cleanliness of spark plug by
ensuring installation tools are clean and free of debris, Do not touch clean ceramic portion of plug. '

11. Tighten spark plug to specification. (See REMOVE AND INSTALL SPARK PLUGS & WIRES in this group.)
IMPORTANT: Wire and metal terminals should be free of dielectric grease at all times. Dielectric grease on.
electrical connections may result in weak or misfiring cylinders. Periodic cleaning and careful installation with
prevent grease from contacting the ignition terminals.

Additional Information :

6081

FOUL, PERFORM, LOSS, WIRE, POWER, MISSING, CHECK, IGNITION, MISFIRE, PLUG, ADJUST, COIL,”
HESITATE, SERVICE, RG. CTM300, GAUGE, NG, POWERTECH, INSTALL, FAIL, PTS, RE64318, RE505994,
RE524020, RE528254, RE51610, ENG, F0400

8/8/2014