Ezgo 605586 Repair And Service Manual page 86

ENGINE
Read all of Section B and this section before attempting any procedure. Pay particular attention to all Notes, Cautions and Warnings.
B
third, or power stroke by the expanding gases. As the
piston reaches BDC it enters the fourth cycle. The
exhaust valve opens and the piston rises forcing burned
gases from the combustion chamber in what is known as
the exhaust stroke. As the piston moves through TDC
and starts down, the first cycle is repeated.
In the engine, there are two pistons that rise and fall
simultaneously, however the valve cycles are staggered.
When one piston is in the compression stroke the other
is in the exhaust stroke. When the spark plugs fire, only
one cylinder is on the power stroke.
In any engine there is vibration caused by the reciprocal
motion of the pistons. In this engine the vibration is mini-
mized by a counter rotating balancer that is driven from
the crankshaft and is synchronized with the power
strokes.
The camshaft is driven from the crankshaft by a toothed
timing belt. The ignition timing is controlled by an electri-
cal pulse received from a timing trigger which is acti-
vated by the crankshaft flywheel hub. The ignition curve
is controlled electronically by the solid state ignitor and
is not adjustable.
Valve Adjustment
Tool List
Flat feeler gauge.......................................................... 1
Straight blade screwdriver ........................................... 1
Box end wrench, 10 mm.............................................. 1
To prevent engine from inadvertently start-
ing, the negative cable must be removed
from battery.
The valves should be checked annually (250 Hours) to
insure that they are in adjustment. A valve that is set too
tight can cause excessive wear to the cam and rocker
and may result in a burned valve. The same is true for a
valve that is set too loose. The valve that is set too loose
may make itself known by a clacking or tapping noise.
The noise can often be masked by other mechanical
noises and go undetected. Poor performance and fouled
spark plugs can result from poor valve adjustment.
Adjustment Procedure
The valve clearances are adjustable from the top of the
engine and should be done with the engine cold (Ref.
Fig. 19 on Page G-9). As an annual (250 hour) inspec-
tion, the valve clearance check consists of removing the
valve cover and sliding a .004" (.10 mm) flat feeler
gauge between the valve rocker and the heel (lowest
Page G-6
portion) of the cam. If the gauge slides in and out with
some light drag felt, the valve does not require any
adjustment.
If the gauge is hard to insert or withdraw, the valve is too
tight. Similarly if the gauge slides in and out with no
resistance, the valve is too loose. To correct either of
these undesirable conditions, loosen the jam nut of the
adjuster and loosen or tighten the adjuster using a snug
fitting straight blade screwdriver. Slide the feeler gauge
back and forth between the rocker and cam until light
resistance is felt. Hold the adjuster with the screwdriver
and tighten the jam nut with a box wrench. Confirm the
adjustment using the feeler gauge and readjust as nec-
essary.
Manually rotate the engine until the cam lobe for the
next valve is in the fully down position and check/adjust
the valve as previously described. Repeat the process
with the remaining two valves.
Valve Cover Installation
Tool List
Socket, 10 mm, 3/8" drive............................................1
Torque wrench, 3/8" drive (in. lbs.) ..............................1
Qty. Required
It is important to use proper tightening procedures when
replacing
cover may result in oil leakage (Ref. Fig. 20 on Page G-
9).
Examine the 'O' ring gasket for nicks, tears or other
damage and replace if any damage is found. Wipe the
valve cover and gasket clean, paying special attention to
the inner groove surface. Position the gasket in the
groove in the valve cover and apply a light coat of oil to
the gasket. Install the valve cover and bolts finger tight.
Stage tighten the bolts in the sequence shown to 60 - 65
in. lbs. (7 Nm) torque.
Timing Belt Adjustment
Tool List
Socket, 12 mm, 3/8" drive............................................1
Ratchet, 3/8" drive .......................................................1
Screwdriver, straight blade ..........................................1
Extension, 3", 3/8" drive...............................................1
Torque wrench, 3/8" drive, ft. lbs..................................1
To prevent the engine from inadvertently start-
ing, the negative cable must be removed from
battery
Repair and Service Manual
the valve cover,since distortion of the valve
Qty. Required
Qty. Required