woodmizer LT25 Guide

G18 Engine
Safety, Operation, Maintenance
& Parts Manual
LT25/LT27 rev. E1.00 - E3.05
Safety is our #1 concern! Read and understand
all safety information and instructions before oper-
ating, setting up or maintaining this machine.
January 2004
Form #1050

©2020
Printed in the United States of America, all rights reserved. No part of this manual may be
reproduced in any form by any photographic, electronic, mechanical or other means or used in
any information storage and retrieval system without written permission from
Wood-Mizer
8180 West 10th Street
Indianapolis, Indiana 46214
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Table of Contents Section-Page
Table of Contents WMdoc031120 iii
TOC
SECTION 1 ABOUT THIS MANUAL 1-IV
SECTION 1 OPERATION 1-1
1.1 Starting The Engine................................................................................1-1
SECTION 2 MAINTENANCE 2-1
2.1 Maintenance ...........................................................................................2-1
2.2 Safety......................................................................................................2-1
2.3 Cooling System ......................................................................................2-2
2.4 Air Filter & Pre-Cleaner.........................................................................2-2
2.5 Fuel Filter ...............................................................................................2-2
2.6 Battery ....................................................................................................2-3
2.7 RPM Adjustments ..................................................................................2-3
2.8 Miscellaneous Maintenance ...................................................................2-4
SECTION 3 REPLACEMENT PARTS 3-1
3.1 Fuel Tank................................................................................................3-1
3.2 Engine Mount Assembly ........................................................................3-2
3.3 Engine Assembly....................................................................................3-3
3.4 Engine Pulley Guards .............................................................................3-5
INDEX I

1-iv 3/11/20
1
SECTION 1 ABOUT THIS MANUAL
This manual is provided as a supplement to the equipment manufacturer’s manuals. This
manual provides information specific to the use of this equipment on the Wood-Mizer®
sawmill. Refer to the sawmill operator’s manual and manufacturer's manual before
attempting to operate this equipment.
IMPORTANT! Read the sawmill operator’s manual and engine manu-
facturer’s manual for instructions and safety precautions before oper-
ating this equipment.
The information and instructions given in this manual do not amend or extend the limited
warranties for the equipment given at the time of purchase.
Air Filter Muffler
Serial Number/
Engine Type
250051-1
Starter

Starting The Engine
3/11/20 1-1
1
SECTION 1 OPERATION
1.1 Starting The Engine
DANGER! Always be sure the blade is disengaged and clear the path
of the blade before starting the engine. Failure to do so will result in
serious injury or death.
DANGER! Operate your engine/machine only in well ventilated
areas.Exhaust gases can cause nausea, delirium and potentially death
unless adequate ventilation is present.
DANGER! Never operate an engine with a fuel or oil leak. The leaking
fuel or oil could potentially come in contact with hot surfaces and ignite
into flames.
WARNING! Do not operate engine without proper and operational
spark arrester/muffler. Sparks emitted from the engine exhaust could
ignite surrounding materials, causing serious injury or death.
CAUTION! EPA Compliant Gas Tanks Only: Always relieve all fuel
pressure inside the tank prior to filling or connecting fuel fittings. Fail-
ure to do so may result in fuel spillage.
CAUTION! EPA Compliant Gas Tanks Only: Disconnect the fuel tank
when not in use, or engine flooding or fuel spillage may result.
1. Close the engine choke by moving the choke lever to the start position.
2. Turn the key switch to the START position and release. Release the key switch to the
RUN position after the engine starts.
3. When the engine starts, slowly open the choke all the way by moving the choke lever to
the off position.
ENGINE SHUTOFF
1. Disengage the clutch handle to stop the blade if necessary.
2. Run the engine for 15 seconds with no load, then turn the key switch to the OFF position.

Maintenance
2-1 3/11/20
2
SECTION 2 MAINTENANCE
2.1 Maintenance
Refer to the manufacturer’s manual for maintenance intervals and procedures unless oth-
erwise instructed in this manual. Follow the manufacturer’s recommendations for dusty
conditions.
IMPORTANT! This manual only provides information about additional
procedures or procedures to be performed at different time intervals
than found in the manufacturer's manuals. Refer to the manufacturer's
manual for complete maintenance instructions.
WARNING! Clean sawdust from all guards, vents, control
boxes, or any area where sawdust may gather after every
shift. Failure to do so may result in fire, causing death or
serious injury.
2.2 Safety
Use caution when performing maintenance or service to the engine.
DANGER! Always be aware of and take proper protective measures
against rotating shafts, pulleys, fans, etc. Always stay a safe distance
from rotating members and make sure that loose clothing or long hair
does not engage rotating members resulting in possible injury.
DANGER! Engine components can become very hot during operation.
Avoid contact with any part of a hot engine. The exhaust components
of your engine are especially hot during and following operation. Con-
tact with hot engine components can cause serious burns. Therefore,
never touch or perform service functions on a hot engine. Allow the
engine to cool sufficiently before beginning any service function.
WARNING! Remove the blade before performing any engine service.
Failure to do so may result in serious injury.
WARNING! Always wear proper and necessary safety equipment
when performing service functions. Proper safety equipment includes
eye protection, breathing protection, hand protection and foot protec-
tion.

Maintenance
Cooling System
Maintenance 3/11/20 2-2
2
This symbol identifies the interval (hours of operation) at which each maintenance pro-
cedure should be performed. "AR" signifies maintenance procedures which should be
performed as required.
2.3 Cooling System
Wash the engine or brush off sawdust and debris every 50 hours of operation. Clean the
grass screen, cooling fins, and external surfaces. Remove any dust, dirt or oil. See
engine manual for further instructions.
2.4 Air Filter & Pre-Cleaner
WARNING! Always wear proper and necessary safety equipment
when performing service functions. Proper safety equipment includes
eye protection, breathing protection, hand protection and foot protec-
tion.
Service the pre-cleaner every four hours of operation. Service by gently shaking excess
sawdust and debris from the foam piece.
Clean the air filter (air cleaner element) and pre-cleaner (element wrapper) every eight
hours of operation. See the engine manual for further instructions.
Replace the air filter (cleaner) every 200 hours of operation.
Replace the pre-cleaner (element wrapper) every 2000 hours of operation.
2.5 Fuel Filter
Replace the fuel filter every 100 hours of operation or as required for engine perfor-
mance.
0
50
4
8
200
2000
100

Maintenance
Battery
2-3 3/11/20 Maintenance
2
2.6 Battery
Check the battery electrolyte level every 50 hours of operation. See manufacturer’s man-
ual for instructions.
DANGER! Batteries expel explosive gases. Keep sparks, flames,
burning cigarettes, or other ignition sources away at all times. Always
wear safety goggles and a face shield when working near batteries.
Failure to do so will cause serious injury.1
WARNING! Battery posts, terminals and related accessories contain
lead and lead compounds, chemicals known to the State of California
to cause cancer and reproductive harm. Wash hands after handling.
2.7 RPM Adjustments
WARNING! Remove the blade before performing any engine service.
Failure to do so may result in serious injury.
Check the RPM with a tachometer every 200 hours of operation.
See Table 2-1.
Before checking the RPM, make sure belt and brake strap tensions are correct (See Saw-
mill Maintenance). Also check oil, fuel, and coolant levels.
Make sure the throttle cable does not affect the engine RPM when the clutch handle is
disengaged. Make sure the cable is not bent or kinked.
1. Start the engine to measure the low-end RPM.
2. Refer to the engine manual to adjust the low-end RPM.
1. Battery Council International, copyright 1987
Engine High End RPM Low End RPM
G18 3750 1800
TAB LE 2- 1
50
200

Maintenance
Miscellaneous Maintenance
Maintenance 3/11/20 2-4
2
3. Engage the clutch handle to throttle the engine and measure the high-end RPM. The
high-end RPM is factory-set at 3750. Readjust the throttle cable if necessary to increase
or reduce the high-end engine speed.
2.8 Miscellaneous Maintenance
Inspect the spark plugs every 100 hours of operation. Remove any deposits and adjust
gap if necessary. See engine manual for further information.
Review the manufacturer's engine manual for maintenance intervals.
100

Replacement Parts
Fuel Tank
3
3-1 25G1801doc031120 Replacement Parts
G18
SECTION 3 REPLACEMENT PARTS
3.1 Fuel Tank
REF DESCRIPTION (Indicates Parts Available In Assemblies Only) PART # QTY.
TANK ASSEMBLY, 5-GALLON RED GASOLINE A12285 1
1 5 gallon gas can assemblies are available only for customers with sawmills and edgers manufactured prior to 2010. Customers with
sawmills and edgers manufactured in 2010 and later need to use new EPA approved 3 or 6 gallon gas can assemblies.
1
1Tank, 5-Gallon Red Fuel P12167 1 
2Pickup, 9" Fuel P12172 1
3Cap, 3 or 5-Gallon Fuel Tank P09683 1
4Fitting, 1/4" NPT Plastic Female Disconnect P12175 1
5Fitting, 3/8” NPT Hex Plug P10367 2
2 Plug fitting P10367 added 11/03. Hole added to fuel tank to accommodate return line for fuel injected engines.
1
6 HOSE, 1/4” ID FUEL P642 6.5 Ft
7 CLAMP, 7/32 - 1/2 HOSE P649 2
8 FITTING, 1/4" NPT PLASTIC MALE DISCONNECT P12176 3
3 Replacement requires qty. 1 hose clamp (P649).
1
1
2
3
4
8
7
6
3H0415C
5

Replacement Parts
Engine Mount Assembly
Replacement Parts 25G1801doc031120 3-2
3
3.2 Engine Mount Assembly
REF DESCRIPTION (Indicates Parts Available In Assemblies Only) PART # QTY.
MOUNT KIT, KOHLER ENGINE 016319 1
1Mount Weldment, Kohler Engine 014514 1 
BUSHING ASSEMBLY, MOTOR MOUNT 016380 3
2Bushing, 2” OD x 2” 016378 1 
3Bearing, 1” x 1 1/4” x 2” 016379 1 
4 CLAMP WELDMENT , MOTOR MOUNT PIVOT BUSHING 014540 3
5 BOLT, 3/8-16 X 1” HEX HEAD F05007-7 3
6 NUT, 3/8-16 HEX NYLON LOCK F05010-10 6
7 BOLT, 1/2-13 X 1 1/4” HEX HEAD GRADE 5 F05008-37 1
8 PIN WELDMENT, ENGINE MOUNT PIVOT 014154 1
9 NUT, 1/2-13 NYLON LOCK F05010-8 1
1
2
3
3
4
4
5
6
6
7
8
9
3H0509-3

Replacement Parts
Engine Assembly
3
3-3 25G1801doc031120 Replacement Parts
G18
3.3 Engine Assembly
REF DESCRIPTION (Indicates Parts Available In Assemblies Only) PART # QTY.
COVER, ENGINE P12393 1
ENGINE ASSEMBLY, 18HP KOHLER 017626 1
1Engine, 18HP Kohler #PA62590 016899 1 
2Filter, Kohler Air #47-083-03 006907 1
3Pre Cleaner, Kohler #24-083-02 006931 1
Plug, RC12YC Kohler Spark #12-132-02 P12757 2
4Filter, Kohler Oil #52-050-02 014717 1
5Filter, Kohler Fuel #24-050-13 P12758 1 1
Pump, Kohler Fuel #24-393-16S 048391 1
6Muffler, Kohler # 1
7Spark Arrestor, Kohler #
Switch, Ignition G18/25 061150 1
8Cable, 18” Throttle P12313 1
Spring, Throttle 016033 1
1
2
3
4
5
8
7
6
9
10
11 12
13
14
15
16
18
20
19
17
22 23
21
26
24
25
250051

Replacement Parts
Engine Assembly
Replacement Parts 25G1801doc031120 3-4
3
G18
9Bracket, Throttle Cable Mount S12312 1
10 Spring, .5” x .08” x 1 3/8” Extension 015952 1
11 Bracket, G25 Throttle 015964 1
12 Bolt, #10-24 x 5/8” Hex Head F05004-18 1
13 Nut, #10-24 Self-Locking F05010-14 1
14 Hose, 7" Oil Drain P10082 1
15 Cap, Oil Drain 3/8" Pipe P04332 1
Oil, 10W30 Type CD L04869-1 .5 Gal 
16 Pulley, 2BK36H Engine 015973 1
17 Bushing, 1 1/8” Split Taper P04306 1
18 Key, 1/4" x 1/4" x 1 11/16" S04124 1
19 Plate, G20 Rear Engine Guard 016420 1
20 Bracket Weldment, Drive Belt Support Painted 015963 1
21 Washer, 3/8” SAE Flat F05011-3 2
22 Washer, 3/8” Split Lock F05011-4 4
23 Bolt, 3/8-16 x 1” Hex Head F05007-7 4
Switch Kit, Kohler Kit 017625 1
Decal, Kohler Key Switch 017639 1
HARNESS ASSEMBLY, BATTERY TO ENGINE 024718 1
24 WASHER, 3/8” SPLIT LOCK F05011-4 4
25 BOLT, 3/8-16 X 1 3/4” HEX HEAD F05007-119 4
26 BELT, 2BX71 DRIVE 036163 2 1
1 Kohler #24-050-13 9-12 micron filter replaces #240-050-10 8-10 micron filter originally supplied.
2 036163 Kevlar 2BXF71 belt replaces P12949 2BX71 belt supplied prior to 9/03. Kevlar belt reduces stretch and provides greater
range of adjustment.

Replacement Parts
Engine Pulley Guards
3
3-5 25G1801doc031120 Replacement Parts
3.4 Engine Pulley Guards
REF DESCRIPTION (Indicates Parts Available In Assemblies Only) PART # QTY.
1 GUARD WELDMENT, KOHLER ENGINE PULLEY 015343 1
2 GUARD, G20/G25 SIDE ENGINE PULLEY 015962 1
3 BOLT, 1/4-20 X 3/4” HEX HEAD WITH CONICAL WASHER F05005-134 8
1
2
3
3
3
250052B

Index 25G1801doc031120 i
M
maintenance 2-1
air cooling system 2-2
battery 2-3
fuel filter 2-2
miscellaneous 2-4
RPM adjustments 2-3
P
parts list
engine assembly 3-3
engine mount assembly 3-2
fuel tank 3-1
pulley guards 3-5
S
starting 1-1
INDEX