Engine Specifications; Engine Description; Engine Operation; Valve Adjustment - E-Z-GO FLEET 1999 Technician's Repair And Service Manual

ENGINE
Read all of Section Band this section before attempting any procedure. Pay particular attention to all Notes, Cautions and Warnings
For further engine information, see Four Cycle Engine
Shop Rebuild and Service Parts Manual, E-Z-GO P/N
27615-G01.
FOUR CYCLE ENGINE

Engine Specifications

Engine model ...................................................... EH29
Type ........................... Four cycle, overhead cam, OHV
Number of cylinders ....................................... 2 (In-line)
Displacement ...................................................... 295 cc
Rated horsepower .................................................... 9.0
Spark plug type ...................................... NGK BPR4ES
Spark plug gap ................... . 028" - .030" (.71 - .76 mm)
Cooling ............................................... Forced air cooled
Oil Filter ...................................... Washable, permanent
Oil Pump ........................................................... Gerotor

Engine Description

The engine is a four cycle air cooled, in line, twin cylinder,
overhead cam unit. It incorporates pressure lubrication, a
washable permanent oil filter and a counter rotating bal­
ance shaft (Ref Fig. 1 on page G-2).
An electronic ignition system fires both spark plugs
simultaneously which eliminates the need for a distribu­
tor. The pistons are aligned together which means that
they both are at TDC (Top Dead Center) and BOC (Bot­
tom Dead Center) at the same time.

Engine Operation

A four cycle engine has a power stroke for each piston
every four strokes or two revolutions of the crankshaft.
Since this engine has two pistons, the engine is timed to
have one power stroke for every rotation of the crank­
shaft. To understand the operation of a four cycle engine,
it is easiest to consider a single cylinder engine.
The first cycle (stroke) takes place with the piston moving
down and the intake valve open (Ref Fig. 2 on page G-
3). Fuel is drawn into the combustion chamber from the
carburetor and through the intake valve and is known as
the intake stroke. As the piston reaches the bottom
(BOC) of its travel and starts to move upwards, the sec­
ond cycle begins. The intake valve closes which seals
the combustion chamber since the exhaust valve is
already closed and causes the fuel air mixture to be com­
pressed as the piston rises. This is known as the com­
pression stroke. Just before the piston reaches TDC
(Top Dead Center) the spark plug fires which causes a
rapid burning of the air fuel mixture. The temperature
rises rapidly which causes the air fuel mixture to expand.
The piston has been carried through TDC by centrifugal
force and is now forced downwards into the third, or
power stroke by the expanding gases. As the piston
reaches BOC 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 E-Z-GO engine, there are two pistons that rise and
fall simultaneously, however the valve cycles are stag­
gered. 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 activated
by the crankshaft flywheel hub. The ignition curve is con­
trolled 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
.A_ WARNING.A_
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.
3 on page G-4). As an annual (250 hour) inspection, the
valve clearance check consists of removing the valve
cover and sliding a .004" (.10 mm) flat feeler gauge
Repair and Service Manual
G
Qty. Required
To prevent engine from
inadvertently starting,
the negative cable must
Page G-1