MD105 RIDE-ON TROWEL • OPERATION MANUAL — REV. #0 (03/29/24) — PAGE 37
4. Inspect the spark plugs (Figure 34). Replace the spark
plugs if they are damaged or badly fouled, if the sealing
washer is in poor condition, or if the electrode is worn.
Figure 34. Engine Spark Plug
5. Measure the spark plug electrode gap (Figure 34) with
a wire-type feeler gauge. If necessary, adjust the gap
to 0.028–0.031 in. (0.7–0.8 mm) by carefully bending
the side electrode.
6. Install the spark plug carefully, by hand, to avoid
cross-threading.
7. After the spark plug is seated, tighten with a 13/16-inch
(21 mm) spark plug wrench to compress the sealing
washer.
8. Attach the spark plug caps to the spark plugs.
GAP
SEALING
WASHER
0.028 – 0.031 in.
(0.7 – 0.8 mm)
ELECTRODE
NOTICE
When installing a new spark plug, tighten 1/2 turn
after the spark plug seats to compress the washer. When
reinstalling a used spark plug, tighten 1/8–1/4 turn
after the spark plug seats to compress the washer.
Torque: 13 lbf·ft (1.8 kgf·m, 18.0 N·m)
NOTICE
A loose spark plug can overheat and damage the
engine. Overtightening the spark plug can damage the
threads in the cylinder head.
MAINTENANCE
4. With the engine in a level position, fill with the
recommended oil (Table 6) to the upper limit mark on
the oil level dipstick. See Table 3 for engine oil capacity.
5. Reinstall the oil ller cap and oil level dipstick securely.
6. Repeat steps 1–5 for the remaining Honda engine.
SPARK PLUGS
To ensure proper performance, the engine spark plugs must
be properly gapped and free of deposits. Recommended
spark plug is BPR5ES (NGK). The recommended spark
plug has the correct heat range for normal engine operating
temperatures.
1. Make sure the engine is cool before servicing the
spark plugs.
2. Disconnect the spark plug caps, and remove any dirt
from around the spark plug area.
3. Remove the spark plugs using a 13/16-inch (21 mm)
spark plug wrench.
NOTICE
Dispose of uids properly in accordance with local and
governmental regulations. NEVER pour uids onto the
ground or down drains or sewers.
NOTICE
SAE 10W-30 is recommended for general use. Other
viscosities shown in Table 6 may be used when the
average ambient temperature is within the indicated
range.
NOTICE
Running the engine with a low oil level can cause
engine damage. This type of damage is not covered
by the Distributor’s Limited Warranty.
NOTICE
Incorrect spark plugs can cause engine damage.
To Next Page
