Troubleshooting And Test Procedures; Preliminary Checks; Testing Cylinder Compression; Compression Test Procedure - Toro 51603 Maintenance And Repair Manual

MAINTENANCE PROCEDURES
4. Start the engine and let
it
warm up for approxi-
mately
3-5
minutes. Do not adjust the carburetor
when the engine is cold. The adjustments should
be made at the temperatures that the trimmer
will be used. Allow the engine to idle. If neces-
sary, re-adjust the idle speed to keep the engine
from stalling
(3000-3500
RPM on the TC400,
3000-4500 on the TC300)
CAUTION:
DO NOT RUN THE TRIMMER
INDOORS WITHOUT ADEQUATE VENTILA-
TION. EXHAUST FUMES ARE POISONOUS
AND COULD BE DEADLY IF INHALED.
5.
With' the engine idling, slowly turn the low speed
screw
clockwise and note the position at which
the engine begins to slow down. Now turn the
screw counterclockwise and again note the posi-
tion when the engine speed is reduced. Set the
screw at
a
point midway between these two
positions.
6. Hold the throttle wide open and follow the same
procedure to set the high speed screw.
7.
Re-check the idle adjustment.
8. Install the air cleaner cover.
TROUBLESHOOTING AND
TEST PROCEDURES
Generally, all gasoline-powered products require
some form of service or repair during their lifetime.
The amount of time and expense involved in repair-
ing
a
product can be greatly impacted by the amount
of time required to initially determine the cause of
the difficulty. Therefore,
it
is recommended to make
these preliminary checks before proceeding to sec-
ondary troubleshooting procedures.
Preliminary Checks
1. Check for ignition:
a. Check the start/stop switch position
2.
Check the spark plug: (refer to specifications.
Page 3)
a.
To ensure the correct type
b. For damage to the insulator
c. For excessive carbon or burnt electrodes
d. For the correct gap
e. Check for spark (refer to page 8 )
3. Check the fuel supply:
a. Check the choke position
b. Check the condition of the fuel, for freshness,
cleanliness, and proper mixture
4. Check the air cleaner: (refer to page 4)
a. For loose or damaged mounting screws
b. For dirty filter elements
c. For excessive oil
in
the foam element
5. Check cylinder compression (refer to
page 7 )
Testing Cylinder Compression
A compression test of the engine can provide vital
information on the general condition of the working
parts within the engine. This
test will indicate a
worn
cylinder, piston, or ring and generally determine
whether
the engine is sound or if it should be
replaced,.
Compression Test Procedure
1. Install the compression gauge into the spark plug
hole. :IMPORTANT: Be certain that no more than a
1/2" o f the gauge is threaded into the cylinder as
damage to the piston may result (Fig. 14).
Figure 1 4
Compression testing
2.
Pull the starter rope several times to obtain the
highest possible compression reading.
3. If the compression reading is below 100 psi (689
kPa), cylinder, piston, or ring damage should be
suspected If so damaged, a new engine
short-
block /should be installed.
7