Now open needle valve 1-1/2 turns counterclockwise and idle valve one turn. This initial adjustment will per- mit the engine to be started and warmed up approx- imately 5 minutes prior to final adjustment.

Final Adjustment-Place speed control lever in FAST position. Turn needle valve in until engine slows (clock-

wise-lean mixture). Then turn it out past smooth operating point (rich mixture). Now turn needle valve to midpoint between rich and lean. Next, adjust idle RPM. Rotate throttle counterclockwise and hold against stop while adjusting idle speed adjusting screw to ob- tain 1750 RPM. Holding throttle against idle stop, turn idle valve in (lean) and out (rich). Set at midpoint be- tween rich and lean. Recheck idle RPM. Release throt- tle. If engine w111not accelerate properly, the carburetor should be re-adjusted, usually to a slightly richer

mixture.

CONTROL ADJUSTMENTS

Proper choke and speed control operation is depend- ent upon proper adjustment of controls on the powered equipment.

To Check Operation

-~~~:;qll~~~J

~-

~ ~

~

°!8-C~'ok~.

Casing

Clamp

Screw

Fast~Position

' E

I '

\~' ,,\

F

Move control lever to CHOKE position. The carburetor

Throttle

Control

Adjustment

choke

should

be closed.

Place speed control lever on equipment in FAST (high

To Adjust

Choke:

 

 

speed) position. Loosen casing clamp screw "C," Move

Place

control

lever on

equipment in CHOKE position.

casing

"A" and wire until lever "E" touches link at "F,"

Loosen casing clamp screw. Move casing and wire until

Tighten casing clamp screw "C." Move control to

choke

is

completely

closed. Tighten casing clampscrew. STOP

position.

Lever must make good contact with

stop switch.

SECTION 5

GENERAL INFORMATION

ENGINE DESIGN

This engine is single cylinder L-head. air-cooled type.

MODEL SERIES 281707

Bore

3-7/16"(87.31

mm)

Stroke

3-1/16" (77.78mm)

Displacement.

28.42 cu. in. (465.7 cc)

Horsepower Max. '."'..'

' .12 @ 3600

APM

Torque (Ft.-Lbs.) Max.

20.5 @ 2400

APM

The horsepower ratings listed are established in accordance with the Society of Automotive Engineers

Test Code-J607. For practical operation, the horsepower loading should not exceed 85% of these ratings. Engine power will decrease 31/2% for each 1,000 feet above sea level and 1 % for each 100 above 600 F.

In some areas, local law requires the use of a resistor spark plug so as to suppress ignition signals. If an engine was originally equipped with a resistor spark plug, be sure to use the same type of spark plug for replacement.

Major engine repairs should not be attempted unless you have the proper tools and a thorough knowledge of internal combustion engines.

TUNE-UP SPECIFICATIONS

Spark

Plug

Type

Champion

Autolite

Short~.

Plug

 

 

CJ-8

235

Long

Plug

 

 

J-8

295

Resistor

Short

Plug

RCJ-8

245

Resistor

Long

Plug

RJ-8

306

Spark

Plug

Gap

 

030"

Intake

Valve

Clearance.

 

005"-.007"

Exhaust

Valve

Clearance.

 

009"-.011"

22

"---T~

Page 21 Page 23
Page 22
Image 22
Bolens MTD7122B09 manual Mixture, To Check Operation, Casing Clamp, This engine is single cylinder L-head. air-cooled type
Page 21 Page 23

MTD7122B09 specifications

The Bolens MTD7122B09 is a reliable and efficient garden tractor that caters to both residential and commercial users seeking a powerful machine for their lawn care needs. This model seamlessly blends user-friendly features and robust technologies, ensuring a seamless mowing experience.

One of the standout features of the Bolens MTD7122B09 is its powerful engine. Equipped with a reliable Briggs & Stratton engine, this tractor offers substantial horsepower and torque, allowing users to tackle even the toughest mowing tasks with ease. The engine is designed for durability and longevity, providing consistent performance year after year.

The cutting deck is another remarkable aspect of the MTD7122B09. With a 42-inch cutting width, it allows users to cover larger areas in less time, making it ideal for both small and medium-sized lawns. The deck features three blade cutting systems, allowing for precise cuts while providing a professional-looking finish. The ability to adjust the cutting height offers versatility, making it suitable for various grass types and terrains.

Comfort is a priority with the Bolens MTD7122B09, and this is reflected in its ergonomic seating and easy-to-use controls. The plush seat is designed to provide maximum comfort during long mowing sessions, while the conveniently located controls ensure users can operate the tractor effortlessly. The steering wheel is adjustable, catering to users of different heights.

In terms of technology, the Bolens MTD7122B09 incorporates innovative system features like a hydrostatic transmission, which delivers smooth shifting and eliminates the need for manual gear changes. This transmission technology enhances maneuverability, making it easy to navigate around obstacles in the yard.

Additionally, the tractor supports mulching capability, bagging, and side discharge, offering users multiple options for grass disposal. These features help maintain a tidy lawn while reducing the need for frequent clean-up.

For safety, the Bolens MTD7122B09 includes safety features such as an automatic shutdown when the operator leaves the seat, ensuring that the mower stops when it is no longer in control.

The Bolens MTD7122B09 is not just a lawn mower; it’s a robust gardening tool designed for efficiency and comfort. Its combination of powerful performance, user-friendly features, and innovative technology makes it an excellent choice for anyone serious about lawn care.
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