Black Max BM4CSSAC Operator's Manual page 15

 Replace the air filter cover by placing the slots on the air
filter cover over the tabs on the housing, then push the
cover down until it latches securely in place.
FUEL CAP, TANK, AND LINES
WARNING:
Check for fuel leaks. A leaking fuel cap, tank, or line is a
fire hazard and must be replaced immediately. If you find
any leaks, correct the problem before using the product.
Failure to do so could result in a fire that could cause
serious personal injury.
The fuel cap contains a non-serviceable filter and a
check valve. A clogged fuel filter will cause poor engine
performance. If performance improves when the fuel cap
is loosened, check valve may be faulty or filter clogged.
Replace fuel cap if required.
SPARK PLUG REPLACEMENT
This engine uses an Champion RY4C or equivalent spark
plug with .025 in. electrode gap. Use a recommended or
equivalent replacement and replace annually.
NOTICE:
Be careful not to cross-thread the spark plug. Cross-
threading will seriously damage the product.
CHANGING ENGINE LUBRICANT
See Figure 17.
WARNING:
Do not change engine lubricant while it is hot. Accidental
contact with hot engine lubricant could result in serious
burns.
For best performance, engine lubricant should be changed
after every 25 hours of operation.
To change the engine lubricant:
 Stop the engine and disconnect the spark plug wire. Allow
the engine to cool completely before proceeding.
 Remove the screw from the top engine cover and set
aside.
 Remove the screws from the bottom engine cover. Remove
the bottom cover and set aside.
 Remove the oil fill cap/dipstick.
 Tip power head on its side and allow lubricant to drain
from the oil fill hole into an approved container.
NOTE: Drain the lubricant while the engine is still warm
but not hot. Warm lubricant will drain quickly and more
completely.
MAINTENANCE
 Return the power head to an upright position and refill
with lubricant following the instructions in the Adding/
Checking Engine Lubricant section previously in this
manual.
NOTICE:
Do not overfill. Overfilling the crankcase may cause
excessive smoke, lubricant loss, and engine damage.
 Reinstall the bottom engine cover. Replace the screws
and tighten securely.
 Replace the screw in the top engine cover and tighten
securely.
NOTE: Used lubricant should be disposed of at an approved
disposal site. See your local retailer for more information.
ADJUSTING CAMSHAFT-TO-ROCKER ARM
CLEARANCE
See Figures 18 - 20.
Inspect the camshaft-to-rocker arm clearance after every
25 hours of operation. This should be done in a clean, dust-
free environment.
NOTE: This procedure requires partial disassembly of the
engine. If you are unsure if you are qualified to perform this
operation, take the unit to a qualified service center.
 Stop the engine and disconnect the spark plug wire. Allow
the engine to cool completely before proceeding.
 Remove the screw from the top engine cover. Remove
engine cover and set aside.
 Using a Torx screwdriver, remove the screw from the
rocker arm cover. Remove the cover and set aside.
 Position camshaft by pulling the starter grip and rope just
until the deep hole in the camshaft gear is located at the
6 o'clock position as shown.
 Place a feeler gauge under each rocker arm and measure
the gap. The gap should be between .004 in. (0.10 mm)
and .006 in. (0.15 mm) for both rocker arms.
NOTE: Use a standard automotive feeler gauge. The
.004 in. (0.10 mm) feeler gauge should slide between
the rocker arm and valve stem with a slight amount of
resistance but without binding. The 0.006 in. (0.15 mm)
feeler gage should not slide between the rocker arms and
the cam lobes — it should be held tight.
 If the valve clearance is not between .004 in. (0.10 mm)
and .006 in. (0.15 mm), the clearance should be adjusted
as follows:
• While holding a wrench on the flats of the adjusting nut
with one hand, loosen the retaining nut with a second
wrench as shown. Take care not to loosen the stud.
• Rotate the adjusting nut until it touches the feeler gauge.
Once the gap setting is correct, hold the wrench on
the flats of the adjusting nut and retighten the retaining
nut securely.
Page 11 — English