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Tecumseh Quick Reference Service Information and Troubleshooting Guide


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Tecumseh

Quick Reference

Service Information

Covers Engine and Transmission Product

Form No.695933 R 7/00

Introduction

This booklet contains the quick reference and basic trouble- shooting information previously found on Tecumseh wall charts and in the Technician's Handbooks.

This booklet is designed to be used as a work bench quick reference guide when servicing Tecumseh engines and motion drive systems.

Technician's Note:

Tecumseh engines are manufactured to meet EPA and CARB standards. As a technician, it is unlawful to re-calibrate or replace a fuel nozzle or jet (bowl nut) with a part from any other carburetor that was not originally designed for that engine. All speed adjust- ments must remain within the limits that are specified for each engine and are not to exceed the maximum. This can only be deviated from if specifically approved by Tecumseh Products, EPA and CARB.

1

Note: Torque specifications listed should not be confused with the torque value observed on engines which have been run.

The Torque specifications take relaxation into account so sufficient clamping force exists after an engine has reached operating temperature.

Torques listed are intended to cover highly critical areas. More extensive torques are found in the respective repair manual.

Torque Specifications

TWO-CYCLE ENGINE SERIES

840 - 850 TWO-CYCLE ENGINE SERIES

Location

Inch lbs. Torque

Nm

Engine Designation

Crankcase to Cylinder

120-204

13.5-23

Flywheel Nut

360-420

41-47.5

Adapter Plate to Cylinder

160-220

18-25

TVS

 

TVXL

 

HSK

 

HXL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

TC TWO-CYCLE ENGINE SERIES

Location

Inch lbs. Torque

Nm

Engine Designation

 

 

 

 

 

 

 

 

 

 

 

 

TC200

TC300

TCH200/ 300

 

 

 

 

 

 

 

 

 

Cylinder to Crankcase

80-95

9-11

 

Crankcase Cover to Crankcase

70-100

8-11

 

 

Flywheel Nut

190-250

21.5-28.5

 

 

 

 

 

 

 

 

 

 

TWO-CYCLE ENGINE SERIES (AV520/600, TVS600, AH520, AH/HSK600)

Location

Inch lbs. Torque Nm

Engine Designation

Connecting Rod

40-50

4.5-5.5

Housing Base to Cylinder

80-120

9-13.5

Cylinder Head to Cylinder

100-140

11-16

Flywheel Nut AV Industrial (Point Ignition)

216-300

24.5-34

(670 Series AV 520 and All AV 600)

 

 

Flywheel Nut (C.D. Ignition)

264-324

30-36.5

AV520/600

 

TVS600

 

AH/HSK600

 

AH520

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

Two Cycle Troubleshooting

As an aid in troubleshooting any piece of equipment, interview the customer, and review conditions and symptoms of the problem. Examine exterior for clues: leaks, excessive dirt, damaged or new parts.

FUEL SYSTEM

Engine Will

Not Start

Check if spark

plug is wet or dry

Wet

Dry

Defective

Review with customer

spark plug

priming or choking

 

 

procedure

 

 

 

 

 

 

(3-5 primes, if

Restricted

equipped, waiting 2

seconds between

air filter

each prime)

 

 

 

 

 

 

 

 

 

 

 

 

 

Carburetion problem*

Improper fuel mix

or stale fuel

(bad bowl gasket)

 

 

 

 

 

 

 

 

 

Check fuel supply

Exhaust ports

and fuel cap vent

plugged

 

 

 

 

 

 

 

 

 

 

 

 

Carburetion

Restriction in

problems due to

fuel system (filter,

flooding, over

screen)

 

priming, etc.*

 

 

 

 

 

 

 

 

 

 

 

 

 

Poor

 

Ignition System

compression

 

 

 

 

 

 

 

 

 

 

 

 

Damaged reed,

port

Crankcase seals

plugs, seals or

or gaskets leaking

gaskets

 

NOTE: Refer to Technician's Handbook for a more

 

 

 

detailed list of remedies.

 

 

 

*Carburetor Troubleshooting use Technician's

 

 

 

Handbook or Carburetor Troubleshooting Booklet,

 

 

 

Form No. 695907. Video No. 695015.

 

 

 

 

(CONTINUED ON NEXT PAGE)

3

Two Cycle Troubleshooting - continued

IGNITION SYSTEM

Engine Will

Not Start

Check for spark

Spark

No Spark

Check flywheel for

correct key, damaged

key or key adaptor

Set proper air gap on

external coil

Set proper point gap, check condensor and timing (if equipped)

Test coil for

intermittent or weak

spark

Check electric starter

if applicable

Replace spark plug

Isolate engine from all equipment (disconnect wiring harness), repeat test

 

Spark

No Spark

 

 

 

 

Equipment problem,

Engine problem,

check switches, wiring

check for shorts or

and equipment

grounds in wiring

controls

 

 

 

 

 

 

 

 

Parasitic load too high

Test ignition module

NOTE: Refer to Technician's Handbook for a more detailed list of remedies.

4

Note: Torque specifications listed should not be confused with the torque value observed on engines which have been run.

The Torque specifications take relaxation into account so sufficient clamping force exists after an engine has reached operating temperature.

Torques listed are intended to cover highly critical areas. More extensive torques are found in the respective repair manual.

Torque Specifications

FOUR-CYCLE LIGHT FRAME ENGINE SERIES

(TVS, TNT, ECV, LAV, LEV, H, HS, OHH, OVRM and VLV)

Location

Inch lbs. Torque

Nm

 

 

 

 

TVS

 

 

 

Rocker Arm Stud Lock Nut

100-140

11-16

 

Connecting Rod

95-110

11-12.5

Cylinder Head

160-210

18-24

Cylinder Head

220-240

25-27

 

Cylinder Head

180-220

20.5-25

 

Mounting Flange or Cylinder Cover

100-130

11-14.5

Flywheel Nut (Cast Iron)

500-600

42-50

Flywheel Nut (Aluminum)

400-500

45-56.5

 

 

 

 

FOUR-CYCLE MEDIUM FRAME ENGINE SERIES

(TVM, TVXL, H, V, HM, OVM, OVXL, OHM, OHSK and OHV)

Engine Designation

TNT

 

ECV

 

LAV

 

H/HSK

 

HS/HSSK

 

OVRM

 

VLV

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

LEV

OHH

Location

Inch lbs.

Nm

 

 

Torque

 

 

 

 

 

TVM125, 140

Connecting Rod

160-180

18-20.5

Connecting Rod

200-220

22.5-25

 

Connecting Rod

200-240

22.5-27

 

Cylinder Head Bolts

220-240

25-27

 

Cylinder Head Bolts

180-240

20.5-27

 

Cylinder Head Bolts

160-210

18-24

Rocker Adj. Lock Screw

65-80

7-9

 

Rocker Arm Stud Lock Nut

110-130

12.5-14.5

 

Rocker Arm Hex Jam Nut

15-20

2

 

Rocker Arm Studs

170-210

19-24

 

Rocker Arm Box to Head

75-130

8.5-14.5

 

Rocker Box Cover

15-20

2

 

Rocker Box Cover (Four Screw)

40-65

4.5-7

 

Mounting Flange or Cylinder Cover 100-130

11-14.5

Mounting Flange or Cylinder Cover 110-140

12.5-16

 

Flywheel Nut

400-550

45-62

Flywheel Nut (External Ignition)

600-800

68-90

 

 

 

 

 

H50-60

V70

H70

Engine Designation

TVM & TVXL 170-195-220

 

HM/HMSK70-100

 

OVM/OVXL, OHV120-125

 

OHSK80-130 OHM120

 

OHV11-13,OHV110- 135, 206 Series

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OHV135-145 203 Series OHV15-17.5 204 Series

5

Torque Specifications - continued

FOUR-CYCLE LARGE FRAME ENGINE SERIES (CAST IRON BLOCK HH, VH and OH)

Location

Inch lbs.

Nm

 

Torque

 

Connecting Rod

86-110

10-12.5

Cylinder Head

180-240

20.5-27

Mounting Flange & Cylinder Cover

100-130

11-14.5

Rocker Arm Shaft to Box

180-220

20.5-25

Rocker Arm Box to Cylinder Head

80-90

9-10

FlywheelNut

600-660

68-74.5

FOUR-CYCLE HEAVY FRAME ENGINE SERIES (V-TWIN)

Location

Inch lbs. Nm

 

Torque

Connecting Rod

200-220 22.5-25

Cylinder Head Bolts

220-240 25-27

Rocker Arm Jam Nut

110-130

12.5-14.5

Rocker Arm Cover Mounting Screw

52

6

Mounting Flange/Cylinder Cover

240-260

27-29

FlywheelNut

600-800

68-90

Engine Designation

HH

VH

OH

 

 

 

 

 

 

 

Engine Designation

TVT

6

Four Cycle Troubleshooting

As an aid in troubleshooting any piece of equipment, interview the customer, and review conditions and symptoms of problem. Examine exterior for clues: leaks, excessive dirt, damaged or new parts.

FUEL SYSTEM

Engine Will

Not Start

Check if spark plug is

wet or dry

Wet

Dry

Defective spark plug

Restricted air filter

Improper or

stale fuel

Carburetion problems due to flooding, over priming, etc.*

Ignition system

Review with the customer proper priming procedure

(3-5 primes, waiting 2 seconds between each prime)

If equipped with a

choke, check for full travel. Check throttle cable and control for proper adjustment.

Check fuel supply and

fuel cap vent

Restriction in fuel

system (filter)

Carburetion problem*

(bad bowl gasket)

Poor

compression

NOTE: Refer to Technician's Handbook for a more detailed list of remedies.

*Carburetor Troubleshooting, use Technician's Handbook or Carburetor Troubleshooting Booklet, Form No. 695907. Video No. 695015.

7

Four Cycle Troubleshooting - continued

IGNITION SYSTEM

Engine Will

Not Start

Check for

spark

Spark

No Spark

 

 

 

 

 

 

 

 

 

Check flywheel for

 

 

 

 

 

 

 

 

 

 

Replace spark plug

correct key, damaged

 

 

 

 

 

 

 

 

 

 

or sheared key

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Isolate engine from all

 

 

 

 

Set proper air gap on

 

 

equipment (disconnect

external coil

 

 

wiring harness), repeat

 

 

 

 

 

 

test

 

 

 

Spark

 

 

 

No Spark

Set proper point gap,

 

 

 

 

check condensor and

 

 

 

 

 

 

 

timing

Equipment problem,

 

Engine problem,

 

 

 

 

 

check switches,

 

 

 

 

 

 

check for shorts or

 

 

wiring and

 

 

 

Test coil for

 

 

 

grounds in wiring

equipment controls

 

 

intermittent or weak

 

 

 

 

 

 

 

 

 

 

 

spark

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Parasitic load too

 

 

Test ignition

 

 

high

 

 

 

module

NOTE: Refer to Technician's Handbook for a more detailed list of remedies.

8

Tecumseh 2 Cycle Diaphragm Adjustments

NOTE: For meeting emission requirements, some carburetors have fixed-main or idle jets. The absence of the adjustment screw indicates fixed jets and no adjustment is necessary.

Diaphragm-Dual Adjustment.

Turn mixture adjusting screws in finger tight to the closed position, then one (1) turn out from closed position. This setting is approximate. This will allow the engine to be started so the carburetor can be fine tuned.

Start the engine and let it warm up for approximately 3-5 minutes. Do not adjust the carburetor when the engine is cold.

IDLE MIXTURE

SCREW

MAIN MIXTURE SCREW

NOTE: If no tension spring is present, it may be a fixed jet.

1

Set the throttle control to idle. If it is a fixed speed type, manually hold the throttle against the idle speed adjustment screw.

The throttle lever must be held against the crack screw for low speed adjustments or all adjustments will be incorrect and cause poor performance and unsatisfactory operation.

With the engine idling and throttle lever against the idle speed regulating screw, turn the low speed adjustment screw slowly clockwise from the NORMAL setting until the engine falters. Remember this location. Turn the screw counterclockwise until engine just starts to sputter or drops in R.P.M.. Remember this location. Turn the screw clockwise until it is halfway between your first position where the engine faltered and your last position where the engine started to sputter. This will be the optimum low speed setting on your carburetor.

Next run the engine at governed speed. The high speed adjustments are made basically the same as the low speed adjustments, with the exception of the settings being made 1/8 of a turn at a time, from the NORMAL settings. NOTE: It may be necessary to re-check the idle mixture adjustment after performing the high speed adjustment.

Diaphragm-Single Adjustment.

Turn the mixture adjustment screw finger tight to the closed position, then one (1) turn out from the closed position. This setting is approximate and will allow the engine to be started so the carburetor can be fine- tuned.

Start the engine and let it warm up for approximately 3-5 minutes. Do not adjust the carburetor when the engine is cold.

Set the throttle control to idle. If it is a fixed speed type, manually hold the throttle against the idle speed adjustment screw.

NOTE: If the engine falters or stops after the choke lever is moved to the "OFF" position, open the mixture adjusting screw 1/4 turn (counterclockwise) and restart the engine.

With the engine running, place the speed control in the "slow" position to make mixture adjustments. Turn the mixture screw slowly clockwise from the NORMAL setting until the engine falters. Remember this location. Turn the screw counterclockwise until the engine just starts to sputter or drops in R.P.M. Remember this location. Turn the screw clockwise until it is halfway between your first position where the engine faltered and your last position where the engine started to sputter. This will be the optimum setting on your carburetor.

9

TC Series Governor Adjustment

Three different styles of governor systems are used on TC engines. Use the following illustrations (diags. 2 and 3) to identify the governor system used and the following procedure to adjust the governed engine speed.

1.Allow the engine to run for at least 5 minutes to reach operating temperature. Make sure the air filter (if equipped) is clean and the choke is in the off position.

2.Using a Vibratach (part# 670156) or other tachometer, determine the engine's R.P.M. at idle and wide open throttle. Refer to Microfiche card 30, or a computer parts look-up program to obtain the recommended engine speeds.

3.Using the applicable illustration, either bend the speed adjusting lever toward the spark plug end of the engine to decrease high speed R.P.M., or bend the lever in the opposite direction to increase R.P.M. On TC Type II engines, turn the speed adjusting screw out to increase or in to decrease engine high speed R.P.M. If the speed adjustment screw is turned out to increase the engine R.P.M., the speed control lever must be moved to allow the speed control plunger to contact the speed adjustment screw.

4.The low speed is set by moving the throttle control to the lowest speed position and adjusting the low speed adjustment screw on the carburetor.

HOOK SPRING ON NOTCH

TYPE I (style 2)

HOOK SPRING ON NOTCH

TYPE I (style 1)

SPEED

ADJUSTING

LEVER

BENDTO INCREASE SPEED BEND TO DECREASE SPEED

SPEED

ADJUSTING

LEVER

2

1.AIR VANE

2.BACKLASH SPRING

3.GOVERNOR LINK

4.GOVERNOR SPRING

5.MOUNTING SCREW

6.SPEED ADJUSTMENT SCREW

7.SPEED CONTROL BODY

8.SPEED CONTROL LEVER

9.SPEED CONTROL PLUNGER

Spring Color

Spring Position

 

 

Orange or Green

1

 

 

Pink, Red, or Black

2

 

 

1

5

TYPE II:

SPRING

HOOK

POSITION 1

SPRING ON

1

NOTCH

 

POSITION 2

8

4

(style 3)

4

9

HIGH SPEED

GOVERNOR

ADJUSTMENT

2

3

SPRING

7

OUT TO INCREASE 6 IN TO DECREASE

INSERT THROTTLE LINK AND SPRING HERE

3

10

Walbro (WTA, WT) and Tillotson (HU) Diaphragm Adjustment

Carburetor Pre-Set and Adjustment

Both the Walbro and the Tillotson carburetors used on TC engines have non-adjustable main mixture jets. Only the idle mixture is adjustable by turning the idle mixture screw. Use the following procedure to pre-set the idle mixture screw. Turn the idle mixture screw (clockwise) finger tight to the closed position, then turn the screw counterclockwise to obtain the proper preset (diag. 4).

Walbro Model WTA, WT 1 - 1-1/8 turns Tillotson Model HU 1-1/4 - 1-3/8 turns

Final Idle Mixture Adjustment

Starttheengineandallowittoreachnormaloperating temperature (after 3-5 minutes). As the speed control is set at the idle position, turn the idle mixture screw slowly clockwise until the engine R.P.M. just starts to decrease. Stop and note this screw position. Turn the idle mixture screw slowly counterclockwise, the engine will increase in R.P.M. Continue to slowly turn the screw until the engine R.P.M. starts to decrease. Note this position and turn the mixture screw back clockwise halfway between the two engine R.P.M. drop off positions. The idle mixture adjustment is complete.

Some carburetors came equipped with a main mixture adjusting screw. To adjust the main mixture, follow the steps for idle adjustment.

IDLE SPEED ADJUSTMENT

SCREW

IDLE MIXTURE

SCREW

4

Emissionized Tillotson

Similar in design and operation, the Tillotson emission carburetor uses a fixed main jet with an adjustable idle. The idle circuit has a limiter cap to prevent over richening. The cap is locked onto the adjustment screw in a rich position, allowing only a leaner adjustment. The main is fixed on these, which means that the main mixture limiter is non-functional on Tecumseh built engines (diag. 4a).

In compliance with E.P.A. and C.A.R.B. regulations the following procedure must be followed.

NOTE: These caps can be removed for servicing of the carburetor. Follow these steps.

1.Turn the caps clockwise until they hit the stops.

2.Remove the caps with a pointed instrument such as an awl.

3.Then turn the screws in until softly seated, note thenumberofturns. Thescrewsmustbereinstalled to this same static setting. Replacement of the caps is required to maintain E.P.A. and C.A.R.B. emission compliance.

IDLE MIXTURE

LIMIT SCREW

FIXED MAIN

(MIXTURE SCREW NOT FUNCTIONAL ON MOST TECUMSEH BUILT ENGINES)

IDLE SPEED

ADJUSTMENT

SCREW

4a

11

2-Cycle Engine Speed and Mixture Adjustments:TVS/TVXL840

IDLE SPEED

ADJUSTMENT

HIGH SPEED

 

 

 

ADJUSTMENT

 

 

 

5

HOLDING

STATIC GOVERNOR

6

SCREW

ADJUSTMENT SCREW

Linkage Location

Static Governor Adjustment

 

To aid in the proper reassembly of the governor linkage, mark the linkage locations.

To adjust the static governor, loosen the holding screw, rotate the governor arm and slotted shaft in the direction that will open the throttle to the wide open position, and then re-tighten the holding screw.

HSK/HXL840-850

IDLE RPM

HIGH SPEED

ADJUSTMENT

RPM

SCREW

ADJUSTMENT

 

SCREW

7

The HXL840 - 850 Series with variable speed control have the following adjustments. Idle speed is set at the carburetor crack screw. High speed is set with the screw shown above. Always check Microfiche card 30 or Parts Smart computer program for correct speed settings.

INCREASE

DECREASE

BEND TAB

8

R.P.M. adjustment of fixed speed models is done by bending the tab as shown.

Governor and Linkage for Air Vane

VANE ASSEMBLY

TO ADJUST HIGH-

SPEED ROTATE

CLOCKWISE TO

INCREASE

COUNTERCLOCKWISE

TO DECREASE 9

BEND TAB TO

ADJUST RPM

DECREASEINCREASE

HORIZONTAL FIXED SPEED

10

PLASTIC AIR VANE GOVERNOR

Rotate sleeve clockwise to increase R.P.M., counterclockwise to decrease R.P.M.

NOTE: The sleeve is serrated to rotate in a clockwise direction and must be raised using the sleeve tabs before it can be rotated counterclockwise.

To disassemble, remove choke shutter with needle-nose pliers; the vane assembly may then be removed from the carburetor.

12

Governors and Linkage for Air Vane - continued

ADJUST RPM BY

LOOSENING SCREW AND

SLIDING BRACKET

DECREASEINCREASE

HORIZONTAL FIXED SPEED

(ALUMINUM AIR VANE GOVERNOR) 11

HIGH SPEED

IDLE RPMRPM

ADJUSTMENTADJUSTMENT

IDLE

MIXTURE

THIS HOLE NOT

PRESENT ON ALL MODELS

SPRING

 

VERTICAL ENGINE

12

VARIABLE SPEED-REMOTE CONTROL

ADJUST RPM BY

SPRING

LOOSENING SCREW AND

 

 

 

 

SLIDING BRACKET

 

 

 

 

INCREASE

 

 

 

 

 

 

 

 

 

 

 

DECREASE

 

 

GOVERNOR LINK

IDLE RPM

ADJUSTMENT

HIGH SPEED

IDLERPM ADJUSTMENT MIXTURE

HORIZONTAL FIXED SPEED

13

THIS HOLE NOT

PRESENT ON ALL

MODELS

 

SPRING

 

VERTICAL ENGINE

14

FIXED SPEED-REMOTE CONTROL

 

HIGH SPEED RPM

 

 

 

 

 

ADJUSTMENT

 

 

 

 

IDLE RPM

 

 

 

 

 

THIS HOLE NOT

ADJUSTMENTS

 

 

 

 

 

 

 

THIS HOLE NOT

 

 

PRESENT ON ALL

 

 

 

 

MODELS

 

 

 

PRESENT ON

 

 

 

 

 

 

 

 

 

 

 

ALL MODELS

RPM ADJUSTMENT

 

SPRING

 

VERTICAL ENGINE

 

 

SPRING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VARIABLE SPEED

15

VERTICAL ENGINE FIXED SPEED

16

MANUAL CONTROL

13

Static Governor Adjustments

 

The purpose of making a static governor adjustment

 

is to remove all free-play between the governor

 

spool and the carburetor (see illustration). Any free-

 

play here will result in hunting/surging or erratic

 

running. After completing this procedure, always

THROTTLE

re-check the engine speeds using the steps outlined

 

in the following pages.

 

To set the static governor, do the following:

1.Be sure the engine is stopped or damage may occur.

2. If equipped with a throttle control, place the throttle in the high speed position.

3. Loosen the governor clamp or screw.

4. Hold the governor arm and link in the W.O.T. (wide open throttle) position, then rotate the shaft or shaft/clip assembly in the same direc- tion and tighten the screw.

5.If engine speed adjustments are needed, follow

the steps described in following pages.

SPRING

CHOKE

GOVERNOR

ROD

NO FREE

PLAYGOVERNOR SPOOL

WIDE OPEN

THROTTLE

CLOSED

THROTTLE

Governor Shaft Pressed In Depth

When assembling governor shaft into a flange or cover mounting boss, refer to this chart for exposed shaft length.

Engine Model

Exposed Shaft Length

Engine Model

Exposed Shaft Length

ECH 90

Mounting flange to top

H 50, 60, 70

Mounting flange to shoulder

ECV 100

1.319 - 1.334"

HH 60, 70

1.283 - 1.293"

 

H 30, 35

(33.502 - 33.883 mm)

HHM 80

(32.588 - 32.842 mm)

HS 40, 50

 

HM 70, 80, 100

 

 

LAV (all)

 

 

 

 

 

 

 

 

LEV (all)

 

OHV 11-17

Mounting flange to top

OHH (all)

 

OVM 120

1.350 - 1.365"

 

OVRM (all)

 

OVXL 120, 125

(34.290 - 34.671 mm)

TNT 100, 120

 

 

 

 

 

 

 

 

TVS (all)

 

OHM 90-120

Mounting flange to top

VLV (all)

 

OHSK 90-130

1.085 - 1.100"

 

 

 

 

(27.559 - 27.940mm)

TVM (all)

Mounting flange to top

 

 

 

 

 

 

 

V 50, 60, 70

1.581 - 1.596"

OH 120-180

Mounting flange to top

VH 50, 60, 70

(25.806 - 26.314mm)

 

1.00"

 

 

 

 

(25.400mm)

HH 100, 120

Mounting flange to top

 

 

 

 

 

 

 

VH 100

1.016 - 1.036"

TVT - V -Twin

Mounting flange to top

 

(25.806 - 26.314 mm)

 

1.196 (3.969 mm)

14

Small Frame, Vertical and Horizontal*

Retainerless Governor System for Small

Models: LAV35,40,50 - H25,30,35 - HS40,50 - HSK - HSSK -

Frames*

TNT100,120 - ECH90 - TVS75,90,105,115,120 - OVRM ALL

 

- ECV100,105,110,120

 

 

 

 

RETAINING

 

 

 

RING

 

 

 

 

SPOOL

 

 

SPOOL

 

 

 

 

UPSET ROLLED

 

 

RETAINING

 

 

 

RING

SHAFT

 

 

 

 

 

GEAR ASSY.

 

 

 

(GOV.)

 

 

 

WASHER

GEAR ASSY.

 

 

 

 

 

 

(GOV.)

 

 

SHAFT

WASHER

 

 

 

 

 

 

NOTE: Gear assembly must have .010 - .020 (.25 - .50 mm) end

 

 

 

play after shaft is installed into flange.

* As of August 1992, all small frame engines, including VLV40-6.75, use

* As of August 1992, all small frame engines, including VLV40-

6.75, use a retainerless shaft. Service replacement shafts will

a retainerless shaft. Service replacement shafts will be retainerless

be retainerless for all small frame and VLV engines.

for all small frame and VLV engines.

 

VLV*40, 50, 55, 60, 65, 66

Medium Frame Vertical

 

 

 

Models: TVM125, 140, 170, 195, 220 - V50,60,70 -

 

 

 

VH50,60,70

TYPE I

SPOOL

TYPE II

RETAINING

 

 

 

 

 

 

RING

 

 

 

SPOOL

RETAINING

 

SPOOL

 

 

 

 

RING

 

 

 

 

 

UPSET

WASHER

 

 

RETAINING

 

 

RETAINER

GEAR ASSY.

 

 

RING

 

SHAFT

 

(GOV.)

 

 

 

 

 

 

 

 

GEAR ASSY.

 

 

GEAR ASSY.

(GOV.)

 

 

 

 

 

(GOV.)

 

 

 

 

WASHER

 

WASHER

 

SPACER

 

 

 

 

 

WASHER

 

 

IDLER

 

 

 

GEAR

.010 - .020 (.25-.50 mm)

 

 

 

 

 

 

CLEARANCE

 

 

 

 

SHAFT

NOTE: Gear assembly must have .010 - .020 (.25 - .50 mm) end play after shaft is installed into flange.

*As of August 1992, all small frame engines, including VLV40-6.75, use a retainerless shaft. Service replacement shafts will be retainerless for all small frame and VLV engines.

15

Medium Frame Horizontal

OHM120 - OHSK 80-130

Models: HH60,70 - H50,60,70 - HM70,80,100 -

 

 

 

 

 

 

 

 

 

 

 

 

HMSK

 

 

 

 

 

 

 

 

 

 

 

 

SHAFT

 

 

 

 

 

SPOOL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WASHER

 

 

 

 

 

 

 

 

ROD ASSY.

 

 

 

 

 

 

 

 

 

RETAINING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RING

(GOV.)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GEAR ASSY.

SPOOL

 

 

 

 

 

 

 

 

 

 

 

(GOV.)

 

 

 

 

 

 

 

 

 

 

 

 

WASHER

 

 

 

 

 

 

 

WASHER

RETAINING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RING

 

 

 

 

 

 

SPACER

 

 

 

 

 

 

 

 

 

 

GEAR

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ASSY.

 

 

 

 

 

 

 

 

 

 

 

 

(GOV)

 

 

 

 

 

 

 

 

 

 

 

 

BRACKET

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SHAFT

SCREWS

OVM120, OVXL120, 125 - OHV11-17

OH120, 140, 160, 180

 

 

 

 

 

SPOOL

 

 

 

 

 

 

 

SPOOL

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WASHER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RETAINING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GEAR ASSY.

 

 

 

 

 

WASHER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(GOV.)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WASHER

 

 

 

 

 

 

 

 

GEAR &

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SPACER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NOTE; SPACER

 

 

 

 

 

 

 

 

SHAFT

 

 

 

 

 

 

 

 

 

 

 

MAY BE PART

 

 

 

 

 

 

 

 

ASSY.

 

 

 

 

 

 

 

 

 

 

 

OF THE GEAR

 

 

 

 

 

 

 

 

(GOV.)

 

 

 

 

 

 

 

 

 

 

 

ASSEMBLY.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SHAFT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

WASHER

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(CAPTURED UNDER

NOTE: On models OHV13.5-17, the spacer is cast as part

 

 

 

 

 

GEAR)

 

 

 

 

 

 

 

 

 

of the governor gear with the washer placed below the

 

 

 

 

 

 

 

 

 

gear assembly.

 

 

 

 

 

 

 

 

 

16

Engine Speed and Mixture Adjustments

3-5 H.P. Vertical Shaft Engines

NOTE: Starting and operating problems may exist when engines are used at high elevations (over 4,000 feet above sea level). In cases where a fixed main carburetor is used, refer to Bulletin 110 for correction. Engines which are identified as compliant with CARB (California Air Resources Board) or EPA (US Environmental Protection Agency) regulations can NOT be changed from their factory jetting unless specifically authorized.

Before making any speed or carburetor adjustments be sure to adjust the governor and control bracket. See Governor Section of the Booklet.

To adjust the speed control bracket, determine whether the carburetor is an adjustable type, then proceed.

Some carburetors may have a choke lever which is operated by the speed control bracket. To adjust the speed control bracket for full choke operation, loosen the speed control bracket mounting bolts and move the speed control lever to the high speed/full choke position. Next insert a small piece of wire through the hole in the speed control bracket, choke actuating lever, and the choke lever (diag. 18). When all three holes are aligned tighten the mounting bolts.

Once the speed control bracket is adjusted, the main and idle fuel mixtures can be adjusted. Start theengineandallowittowarmuptonormaloperating temperature (3 - 5 minutes). Set the speed control to the HIGH or FAST position, then turn the main mixture adjustment screw in (clockwise) slowly until the engine begins to run erratic (lean). Note the position of the screw. Now, turn the screw out (counterclockwise) until the engine begins to run erratic (rich). Turn the screw in (clockwise) midway between these two positions. This will be the best setting.

Set the speed control to the IDLE or SLOW position. Adjust the idle mixture screw following the same procedure used to adjust the main mixture adjustment.

NOTE: SOME CARBURETORS HAVE FIXED MAIN JETS. THE ABSENCE OF THE ADJUSTING SCREW INDICATES A FIXED JET AND NO ADJUSTMENT IS NECESSARY.

After adjusting the fuel mixtures, engine speeds can be adjusted. The correct operating speeds are found on Microfiche card 30 of the Tecumseh Master Parts Manual, or the computer parts look-up program (Part Smart). On engines with adjustable carburetors (diag. 19 and 20) the high speed adjustment will be in one of two places. The first location is on the speed control lever (diag. 19).

 

 

** NON-ADJUSTABLE

* ADJUSTABLE

NO CHOKE

 

PRIMER

 

MIXTURES, CHOKE

17

 

SPEED CONTROL

SMALL WIRE (DRILL BIT)

MOUNTING BOLTS

 

 

 

 

HOLE IN BRACKET

 

 

 

 

 

HOLE IN SPEED

CONTROL CHOKE

ACTUATING LEVER

 

HOLE IN CHOKE

 

LEVER

 

18

HIGH SPEED

LOW SPEED

ADJUSTMENT SCREW

ADJUSTMENT SCREW

IDLE MIXTURE

 

MAIN MIXTURE

 

SCREW

 

SCREW

19

17

Engine Speed and Mixture Adjustments - continued

3-5 H.P. Vertical Shaft Engines

HIGH SPEED

LOW SPEED

SPEED CONTROL

ADJUSTMENT SCREW

ADJUSTMENT

MOUNTING BOLTS

 

SCREW

 

 

COUNTERCLOCKWISE

TO INCREASE SPEED

CLOCKWISE TO

DECREASE SPEED

IDLE

MIXTURE

SCREW

MAIN MIXTURE SCREW

20

The second is on a bracket located between the blower housing and the speed control (diag. 20). Low speed is adjusted by the throttle crack screw on the carburetor (diag. 19 and 20).

It may be necessary to preset the carburetor mixture screws.

Tecumseh Carburetors

 

Engine Model

Main Pre-set

Idle Pre-set

All models with

 

 

float-type carburetors

1-1/2 turn

1 turn

 

 

 

All models with

 

 

diaphragm-type

 

 

carburetors

1 turn

1 turn

 

 

 

Some speed control brackets are adjusted by loosening the speed control bracket mounting bolts and sliding the bracket all the way to the right and re- tightening the mounting bolts (diag. 21). The high speed adjustment screw is located on the speed control lever (diag.22) Some carburetors are fixed speed and are adjusted by bending the adjusting tab attached to the intake manifold (diag. 23).

After setting the engine speeds recheck the fuel mixtures, then recheck the engine speeds.

 

21

HIGH SPEED

LOW SPEED

ADJUSTMENT

ADJUSTMENT SCREW

SCREW

 

 

 

 

22

SPEED ADJUSTMENT TAB

BEND TO INCREASE SPEED

BEND TO DECREASE SPEED

23

18

Engine Speed and Mixture Adjustments - continued

3-5 H.P. Vertical Shaft Engines

LOW SPEED TAB

HIGH SPEED TAB

BEND

TO INCREASE SPEED

 

BEND

TO DECREASE SPEED

 

 

 

 

HIGH SPEED

 

 

 

 

PIN POSITION

 

 

 

 

 

 

 

BEND CONTROL

 

 

 

BRACKET TO SET

 

 

 

 

RPM

TOOL

DECREASE

 

 

 

 

 

 

 

(670326)

INCREASE

 

 

 

 

 

 

 

SNAP IN CONTROL

24

VERTICAL ENGINES

25

GOVERNED / NON-GOVERNED IDLE

With the engine running at its lowest speed, set the governed idle at the designated R.P.M. by bending the idle R.P.M. tab. Next set the non-governed idle by pushing the bottom of the governor lever away from the control brackets, so the throttle lever contacts the idle speed screw. Hold the lever in this position and turn the idle adjustment screw clockwise to increase or counterclockwise to decrease engine idle speed. The setting on the carburetor screw should be set at 600 R.P.M. below the governed idle setting. This setting prevents the throttle plate from closing when going from high speed R.P.M. to low speed R.P.M. If improperly adjusted, the engine could experience an over lean condition.

HIGH SPEED RPM

ADJUSTMENT

SCREW

TVS 115 ENGINE WITH DUAL

 

SYSTEM CARBURETOR

26

BEND TO INCREASE SPEED

BEND

TO DECREASE SPEED

HIGH SPEED

RPM

ADJUSTMENT

SCREW

IDLE SPEED

CRACK SCREW

VERTICAL SHAFT ENGINES

27

 

NOTE:

ON REMOTE CONTROL

THIS WILL NOT BEHIGH SPEED ADJUST PRESENT

LOW SPEED ADJUST

TNT 100 VERTICAL ENGINES

28

OVRM

29

19

VLV Governor and Linkage

Governor Adjustment

With the engine stopped, loosen the screw holding the governor clamp and lever. Turn the clamp clockwise, then push the governor lever (connected to the throttle) to a full wide open throttle position. Hold the lever and clamp in this position and tighten the screw.

Linkage Installation

The solid link is always connected from the throttle lever on the carburetor to the lower hole on the governor lever. The shorter bend has to be toward the governor. The governor extension spring is connected with the spring end hooked into the upper hole of the governor lever and the extension end hooked through the speed control lever. To remove the governor spring, carefully twist the extension endcounterclockwisetounhooktheextensionspring at the speed control lever. Do not bend or distort the governor extension spring (diag. 30).

Speed Controls

This engine has an adjustable speed control. Never exceed the manufacturer's recommended speeds.

NOTE:Governor adjustment screw will be a Torx head (T-10) effective August 1, 1996 for E.C. Compliance.

Fixed Speed

High speed governor adjustment is accomplished by bending a tab to increase and decrease engine R.P.M. Effective August 1997 (diag. 31a).

TWIST COUNTERCLOCKWISE

TO DISCONNECT

GOVERNOR SPRING

SHORT BEND LONG BEND

30

HIGH SPEED ADJUSTMENT

COUNTERCLOCKWISE INCREASES SPEED

LOWSPEEDADJUSTMENT

COUNTERCLOCKWISEINCREASESSPEED

31

TOOL 670326

HIGHSPEED

BEND

 

TO INCREASE SPEED

 

 

 

ADJUSTMENT

BEND

 

 

TO DECREASE SPEED

31A

 

 

 

FIXED SPEED

20

Engine Speed and Mixture Adjustments

5-15 HP Vertical Shaft Engines

The first stepis adjusting the speed control bracket for full choke operation. Loosen the two speed control bracket mounting bolts and move the control lever to the full high speed/full choke position. Insert a piece of wire through the hole in the speed control bracket, the choke actuating lever, and the choke lever (diag. 32). When all three holes are in alignment retighten the speed control bracket mounting bolts.

SMALL PIECE OF WIRE

HOLE IN

HOLE IN CONTROL BRACKET

CHOKE

 

ACTUATING

MOUNTING

LEVER

BOLTS

 

MOVE THE CONTROL

 

LEVER IN THE HIGH

HOLE IN CHOKE LEVER

SPEED POSITION

 

The second step is adjusting the main and idle fuel mixtures. Start the engine and allow it to warm up to normal operating temperature (3 - 5 minutes). Set the speed controls to the HIGH or FAST position, then turn the main mixture adjustment screw in (clockwise) slowly until the engine begins to run erratic (lean). Note the position of the screw. Now, turn the screw out (counterclockwise) until the engine begins to run erratic (rich). Turn the screw in (clockwise) midway between these two positions. This will be the best setting.

Set the speed control to the IDLE or SLOW position. Adjust the idle mixture screw following the same procedureusedtoadjustthemainmixtureadjustment screw.

NOTE: SOME CARBURETORS HAVE FIXED MAIN JETS. THE ABSENCE OF THE ADJUSTING SCREW INDICATES A FIXED JET AND NO ADJUSTMENT IS NECESSARY.

The third step is setting engine speeds. The correct engine operating speeds are listed on card 30 of the Tecumseh Master parts manual microfiche, or the computer parts look-up program (Part Smart or Plus One). The most common speed control bracket (diag. 33) has the high speed adjustment screw located on the speed control lever. The low speed adjustment screw is the throttle crack screw on the carburetor body. Another common speed control is the governor override system (diag. 34). This system has a similar speed control bracket along with a governor adjustment lever which is attached to the engine block. Both the high speed

32

HIGH SPEED

ADJUSTMENT SCREW

THROTTLE

CRACK

SCREW

IDLE MIXTURE

SCREW

MAIN MIXTURE

SCREW 33

THROTTLE CRACK SCREW

GOVERNOR

ADJUSTING LEVER

IDLE

HIGH SPEED

MIXTURE

ADJUSTMENT

SCREW

SCREW

 

and low speed adjustment screws are located on the governor adjusting lever.

MAIN MIXTURE SCREW

LOW SPEED ADJUSTMENT SCREW

34

21

Engine Speed and Mixture Adjustments - continued

2.5-17.5 HP Vertical Shaft Engines

To adjust high speed on an up/down control (diag.35) bend the adjustment tab. Low speed is adjusted by a screw at the bottom of the control bracket. Both the governor override system and the up/down speedcontrolhaveagovernedidle. Onthese systems it is important to also adjust the throttle crack screw. To adjust the throttle crack screw use your finger to hold the throttle shutter tight against the throttle crack screw and adjust the engine speed to approximately 600 R.P.M. less than the recommended low speed.

After setting the engine speeds recheck the fuel mixtures and double check the engine speeds.

NOTE: Not all engines have fully adjustable carburetors.

It may be necessary to preset the carburetor mixture screws.

THROTTLE CRACK HIGH SPEED ADJUSTMENT TAB

SCREW

BEND

TO INCREASE SPEED

 

 

 

 

BEND

TO DECREASE SPEED

 

 

LOW SPEED

IDLE MIXTURE

MAIN MIXTURE

ADJUSTMENT

SCREW

SCREW

SCREW 35

Tecumseh Carburetors

Engine Model

Main Pre-set

Idle Pre-set

All models with

 

 

float-type carburetors

1-1/2 turn

1 turn

All codels with

 

 

diaphragm-type

 

 

carburetors

1 turn

1 turn

 

 

 

CHOKE

HOOKUP

HIGH SPEED

GOVERNED

 

 

 

IDLE SPEED

 

 

 

ADJUSTMENT

 

 

 

SCREW

IDLE SPEED

TAB

 

THROTTLE

 

CRACK

 

 

LINK HOOKUP

 

SCREW

 

 

 

 

 

ALIGNMENT

CHOKE LEVER

 

 

HOLE

 

AIR GAP

 

 

 

 

 

 

 

 

 

(.040 - .070")

 

 

 

 

(1.0 - 1.8 mm)

IDLE MIXTURE

 

 

 

BEND TAB TO

 

 

 

ADJUST

 

SCREW

TOOL #670326

TVXL220, OHV 11-17 STYLE SPEED CONTROL

36

The idle speed is adjusted by turning the idle speed screw clockwise to increase engine R.P.M. and counterclockwise to decrease R.P.M. Use tool part # 670326 to adjust the high speed engine R.P.M. Place the slotted end of the tool onto the adjustment tab and bend the tab to the left (toward the spark plug end) to increase engine R.P.M. (diag. 36).

NOTE: Be sure that the throttle cable has full travel from wide open throttle to full choke. Hard Starting could result if the cable is not properly adjusted to allow for full choke.

22

Engine Speed and Mixture Adjustments - continued

LOW SPEED TAB

HIGH SPEED TAB

NOTE: ON REMOTE

HIGH SPEED ADJUST

HIGHSPEED

 

CONTROL THIS

 

PIN POSITION

 

WILL NOT

LOW SPEED ADJUST

 

 

BE PRESENT

 

 

DECREASE

 

 

 

 

 

 

 

 

INCREASE

 

 

OVRM SNAP IN CONTROL

37

OVRM

38

 

 

 

OVRM

 

STANDARD TVM ENGINE WITHOUT

 

39

GOVERNOR OVERRIDE

40

SPEEDCHANGES APPROXIMATELY 200 RPM PER SLOT

MAIN MIXTURE

 

 

 

SCREW

 

 

 

GOVERNOR ADJUSTING

HIGH SPEED

 

 

SCREW (LOW SPEED)

 

 

 

 

 

OVM/OVXL,TVM 170, 195 & 220

41

OHV 11-17

Governor Override System for TVM170, 195 and 220 Engines (diag. 41)

This system will be found starting on 1985 production models and will not retrofit onto older engines. It is designed to allow the governor to regulate the low and high speeds of the engine. The high speed is adjusted at the top screw of the override lever; to increase R.P.M. turn the screw out (counterclockwise), to decrease R.P.M. turn the screw in (clockwise). The low speed is adjusted at the bottom screw of the override lever; to increase R.P.M. turn the screw in or clockwise, to decrease R.P.M. turn the screw out or counterclockwise (diag. 41).

23

Engine Speed and Mixture Adjustments -

Horizontal Shaft Engines

IDLE SPEED

 

 

IDLE SPEED

 

CRACK SCREW

 

 

 

 

 

CRACK SCREW

 

 

 

 

 

 

 

HIGHSPEEDRPM

 

 

HIGHSPEEDRPM

 

ADJUSTMENT

 

 

 

 

 

 

 

ADJUSTMENT

 

 

SCREW

 

 

 

 

 

 

 

 

 

 

 

 

 

SCREW

 

 

 

 

 

 

 

 

HORIZONTAL LIGHTWEIGHT

42

LIGHTWEIGHT R.V. TYPE

43

IDLESPEEDCRACKSCREW

 

HIGHSPEEDRPMADJUSTMENTSCREW

 

HIGHSPEEDRPM

ADJUSTMENT

SCREW

IDLE MIXTURE

SCREW

MAIN

MIXTURESCREW

SMALL FRAME GOVERNED IDLE 44

IDLE SPEED CRACK SCREW

IDLE

MIXTURE

MAIN

MIXTURE

HIGHSPEEDRPM

ADJUSTMENTSCREW

CONSTANT SPEED APPLICATIONS 46

IDLE SPEED

CRACK SCREW

HORIZONTAL MEDIUM FRAME 45

HIGHSPEEDRPMADJUSTMENTSCREW

IDLE SPEED

CRACK SCREW

IDLEMIXTURESCREW

HORIZONTAL MEDIUM FRAME

47

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

HM / OHM

NOTE: Since 1996, all speed adjustment screws will have a torx head.

24