page 1 of 1 carburetion -...

Carburetor Adjustment

Initial

1. Turn adjustment needle clockwise until it makes light contact with the seat. Do not force.

2. The initial setting of adjustment needle is made by turning out (counter-clockwise) 1-1/2 turn. Final adjustment is made

with engine running.

3. Install complete air cleaner assembly.

Note: When starting a Pulsa-Jet engine for first time, fill fuel tank completely full. This eliminates priming the fuel pump,

thus ensuring a quick start.

Final

1. Start and run engine at half throttle for five minutes to bring engine up to operating temperature.

2. Place governor speed control lever in "FAST" position.

3. Turn adjustment needle in until engine misses (clockwise - lean mixture) then turn it out past smooth operation point until

engine runs unevenly (counter-clockwise - rich mixture).

4. Turn adjustment needle to midpoint between rich and lean so engine runs smoothly.

5. Place equipment control lever in ''SLOW'' position.

6. Adjust idle RPM. Rotate throttle shaft counter-clockwise and hold against idle stop while adjusting idle speed adjusting

screw to obtain 1750 RPM.

7. Hold throttle shaft in the idle position. Move speed control to fast position.

8. Release throttle shaft. Engine should accelerate without hesitation or sputtering.

9. If engine does not accelerate smoothly, carburetor should be readjusted, usually to a slightly richer mixture.

CARBURETION

Tank Mount, Horizontal Crankshaft

Pulsa-Jet - Adjustable Main Jet

Single Cylinder "L" Head Engine Repair ManualVersion 1.0

Copyright© 1999 by Briggs and Stratton Corporation

of 1

Assemble Carburetor

Fuel Pump

1. Smooth side of cup must rest against diaphragm,

Fig. 77. This prevents spring from cutting diaphragm.

2. When installing pump cover, tighten screws evenly in

staggered sequence to ensure a good seal.

3. Inspect all sealing surfaces for nicks or damages and

repair or replace as required.

CARBURETION





Page 1 of 4

Fig. 77 - Pulsa-Jet Carburetor

Pick-Up

Tube

Cover

Cap

Diaphragm

Spring

Assemble Choke-A-Matic® Linkage

Rotary Choke

1. Insert "Z" bend of Choke-A-Matic® linkage into same

hole as return spring.

2. Slide washer on the end of linkage and then slide

Choke-A-Matic® lever onto shaft.

3. Install lever assembly and stop switch on carburetor,

Fig. 79.

Note: Hook small end of spring on spring post and

long hook in bottom hole of choke shaft, Fig. 80.

Slide Choke

1. To assemble, slip washers and spring over choke

link, Fig. 81.

2. Hook choke link through hole in choke slide. Place

other end of choke link through hole in speed

adjustment lever.

3. Mount lever and stop switch insulator plate to

carburetor.

Manual Choke

Note: Bottom tooth of choke shaft should engage top

tooth on manual choke lever, Fig. 82.

CARBURETION





Page 2 of 4

Fig. 79 - Assembling Choke-A-Matic® Linkage

Fig. 80 - Assembling Choke-A-Matic® Spring

Fig. 81 - Assemble Choke-A-Matic® Linkage

Fig. 82 - Choke Shaft Engagement

"Z" Bend

Return Spring

Spring Post

Choke Link

First Tooth

Bottom Tooth

Install Spiral

When inserting spiral, top must be flush to 1/32" (.8 mm)

below carburetor flange, and spiral parallel with fuel

tank mounting surface, Fig. 83.

Install Throttle Shaft & Plate

Cast Style Throttle Shaft

1. If Pulsa-Jet carburetor body had a throttle shaft seal,

install new seal with sealing lip up.

2. Place new dust seal on throttle shaft and install in

carburetor body.

3. Install throttle plate in carburetor body and install

throttle plate screw, Fig. 84.

CARBURETION





Page 3 of 4

Fig. 83 - Installing Spiral

Fig. 84 - Install Cast Throttle Shaft & Plate

Spiral

Throttle

Plate

Throttle

Plate Screw

Install Throttle Shaft & Plate

Stamped Throttle Shaft

1. Press in new rubber throttle shaft seal with sealing lip

down until seal bottoms.

2. Place new foam seal on throttle and insert shaft in

carburetor body. Throttle plate is chamfered and has

an identification letter stamped on one side of plate.

3. Place throttle plate in carburetor with stamped letter

as shown in Fig. 85, and install throttle plate screw.

Install Choke Shaft & Plate

1. Place metal washer next to choke lever and then

foam washer.

2. Insert shaft assembly in carburetor body with stop

against remote control boss.

3. Insert choke plate in shaft with hole up and

indentations towards large welch plug, Fig. 86.

Note: On Choke-A-Matic® carburetors, be sure that

both ends of choke spring are engaged before

sliding shaft all the way into carburetor.

Install Fuel Pick-Up Tube

Slide new retainer clip onto brass pipe. Heat small end

of new nylon tube in hot water and push onto brass

pipe. Slide retaining clip onto nylon tube over groove on

brass pipe, Fig. 87.

CARBURETION


Pulsa-Jet, Fixed Jet



Page 4 of 4

Fig. 85 - Installing Stamped Throttle Shaft

Fig. 86 - Install Choke Shaft & Plate

Fig. 87 - Install Fuel Pick-Up Tube

Stamped

Letter

Hole

UpFoam or Felt

Washer

Metal WasherSpring End

Retainer Clip

Groove

Disassemble Choke-A-Matic® Linkage

Rotary Choke

1. To remove choke link, remove speed adjustment lever

and stop switch insulator plate.

2. Work link out through hole in choke shaft, Fig. 73.

Disassemble Choke-A-Matic® Linkage

Slide Choke

1. To remove choke link, remove speed adjustment lever

and stop switch insulator plate.

2. Remove speed adjustment lever from choke link.

3. Pull out choke link through hole in choke slide, Fig. 72.

4. On models equipped with a stop switch, remove stop

switch wire.

CARBURETION





Page 1 of 4

Fig. 73 - Choke-A-Matic® Linkage Rotary Choke

Fig. 72 - Choke-A-Matic® Linkage Slide Choke

Choke

Link

Choke

Link

Disassemble Carburetor

Remove Throttle Plate & Shaft

1. Remove throttle plate screw and throttle plate, Fig. 63.

2. After removal of throttle plate, throttle shaft and dust

seal may be lifted out, Fig. 63.

Note: Some Pulsa-Jet carburetors have a throttle

shaft seal in addition to the dust seal. Remove,

discard and replace.

3. Remove adjustment needle assembly.

4. Remove brass seat

5. Snap out choke plate and remove choke shaft.

CARBURETION


Pulsa-Jet, Adjustable Jet



Page 2 of 4

Fig. 63 - Remove Throttle Plate (Typical)

Fig. 74 - Remove Choke Shaft & Plate, Rotary Choke

Throttle

Plate

Throttle

Plate

Screw

Pencil

Felt

Washer

Metal

Washer

Choke

Shaft


Remove adjustment needle and Seat

1. Remove adjustment needle to inspect.

2. Replace needle valve if needle is bent, grooved, or

broken, Fig. 66.

3. If carburetor is gummy or dirty, remove seat to allow

better access to metering holes.

Note: DO NOT change metering hole sizes. Use only

compressed air or solvents to clean metering

holes.

Remove Fuel Pick-Up Tube

1. To remove screen housing or nylon pipe from brass

pipe, slide retaining clip up onto brass pick-up tube.

2. Cut end of nylon tube where tube connects to brass

tube and remove tube.

3. Slide off old retaining clip and discard, Fig. 68.

Note: DO NOT remove brass pipe.

CARBURETION





Page 3 of 4

Fig. 66 - Mixture Needle

Fig. 68 - Remove Pick-Up Tube, Typical

Replace

Good

Disassemble Fuel Pump

1. Remove fuel pump cover, diaphragm, spring and cup,

Fig. 71.

2. Inspect diaphragm for punctures, cracks and fatigue.

Replace if damaged. Inspect all sealing surfaces for

nicks or damages and repair or replace as required.

Remove Spiral

Note: Some carburetor models have a spiral in

carburetor bore.

1. To remove, clamp carburetor in a vise with smooth

jaws about half an inch below top of jaws.

2. Grasp spiral firmly with a pair of pliers, as shown,

Fig. 70.

3. Place a screwdriver under ledge of pliers.

4. Using edge of vise, push down on screwdriver

handle to pry out spiral.

5. Inspect gasket surface of carburetor. Repair if

mounting surface is damaged.

CARBURETION





Page 4 of 4

Fig. 71 - Pulsa-Jet Fuel Pump

Fig. 70 - Remove Spiral

Cover

Diaphragm

Cup

Spring

Remove Carburetor

Models 91200 92200, 94200

1. Remove air cleaner assembly.

2. Move throttle (top) lever to idle position.

Note: On fixed adjustable control panels, bend tang

down to move throttle lever to idle position.

3. Move choke (bottom) lever to full choke position,

Fig. 60.

4. Use a T-20 Torx® driver or flat blade screwdriver to

remove two (2) screws holding control panel to fuel

tank and carburetor (when used).

5. Remove control panel and disconnect choke rod and

stop wire from stop switch (when used).

Models 80200, 82200, 90200, 91200 92200, 112200,

130200, 132200, 135200, 136200, 137200


2. Disconnect choke link from control panel lever,

when used.

3. Remove two (2) screws holding control panel and

remove control panel.

4. Disconnect stop switch wire from stop switch and

set control panel aside.

5. Using Tool #19305 Offset Screwdriver, Tool

#19391Torx® Wrench, Tool #19442 Torqux Star bit

set or open end wrench, remove two screws holding

carburetor to cylinder.

6. Remove assembly while disconnecting throttle linkage

or governor rods.

CARBURETION





Page 1 of 2

Fig. 61 - Remove Control Panel

Fig. 89 - Remove Carburetor & Fuel Tank On Engine


Bend

Tang

Control

Panel

Tool

# 19305

Bottom

Screw

Control

Cable

Remove Fuel Tank from Carburetor

1. Remove remaining screws holding fuel tank onto

carburetor.

2. Remove screw holding fuel tank bracket to cylinder

base.

3. Separate fuel tank from carburetor and remove fuel

tank gasket and discard.

4. Disconnect governor linkage and spring from

carburetor.

CARBURETION





Page 2 of 2

Fig. 62 - Remove Fuel Tank From Carburetor (Typical)

Gasket

Adjustable Pulsa-Jet Carburetors with Choke-A-

Matic®, Manual or Remote Choke, Models 60000,

80000, 90000, 100000, 110000, 130000

These Pulsa-Jet carburetors all have a combined idle

and main jet adjustment needle, integral fuel pump and

have either rotary or slide choke in manual, remote or

Choke-A-Matic®, Fig. 59.

CARBURETION





Fig. 59 - Pulsa-Jet Carburetors with Adjustable Jet

Rotary Choke-A-

Matic®

Manual Rotary

Choke

Manual Choke

High Altitude Compensation

(except Low Emissions Carburetors)

Note: If engine is operated at high altitudes,

performance may decrease. If poor performance

is experienced remove main air bleed jet, Fig. 75.

High Altitude Compensation

Low Emissions Carburetors

Note: For Low emission carburetors (type numbers

ending in A1 through A9 or E1 through E9) use

the following procedure:

1. Remove end welch plug.

2. Using a #3-48 UNC tap, tap into main air bleed jet,

Fig. 75.

3. Clamp square end of tap in vise and turn carburetor

body clockwise to pull air bleed jet.

4. Press new high altitude air bleed jet in until flush with

boss.

5. Remove original pilot jet and install new high

altitude pilot jet.

CARBURETION





Fig. 75 - Remove Main Air Bleed

Main Air

Bleed

Final Adjustment

Low Emissions Carburetors (with type numbers

ending in A1 through A9 or E1 through E9)

1. Start and run engine for five minutes to warm up

engine before making final adjustments.

2. Place speed control in slow position.

3. Rotate throttle counter-clockwise and hold against the

idle stop while adjusting idle speed adjusting screw to

obtain 1500 RPM.

Note: Current production carburetors have a pilot jet.

These carburetors can be identified by not having

an idle mixture needle spring.

4. Release throttle and bend governed idle bracket to

obtain 1750 RPM, Fig. 94.

CARBURETION





Page 2 of 2

Fig. 94 - Adjust Governed Idle

Carburetor Adjustment

Note: On low emission carburetors, only idle speed and governed idle speed is adjustable

Initial Adjustment (except type numbers ending in A1 through A9 or E1 through E9)

1. Turn adjustment needle clockwise until it makes light contact with the seat (do not force).

2. Turn adjustment needle 1-1/2 turns counter-clockwise

3. Install complete air cleaner assembly.

Final Adjustment (except type numbers ending in A1 through A9 or E1 through E9)

1. Start and run engine at half throttle for five minutes to bring engine up to operating temperature.

2. Place governor speed control lever in "SLOW" position.

3. Turn adjustment needle in clockwise until engine misses; then turn it out counter-clockwise past smooth operation point

until engine idles unevenly.

4. Turn adjustment needle to midpoint between rich and lean so engine idles smoothly.

5. Adjust idle RPM. Rotate throttle shaft counter-clockwise and hold against idle stop while adjusting

idle speed adjusting screw to obtain 1750 RPM.

7. Hold throttle shaft in the idle position. Move speed control to fast position.

8. Release throttle shaft. Engine should accelerate without hesitation or sputtering.

9. If engine does not accelerate smoothly, carburetor should be readjusted, usually to a slightly richer mixture.

Governed Idle

Bracket

Assemble Carburetor to Fuel Tank

1. Place new tank gasket on fuel tank.

2. Lower carburetor into fuel tank and install mounting

screws closest to choke plate first. Fig. 62.

Install Carburetor and Fuel Tank

1. Connect governor linkage to carburetor linkage.

2. Using Tool #19305, Offset Screwdriver, or Tool

#19391, Torx® Wrench, or open end wrench, start

two (2) screws holding carburetor to engine, Fig. 89.

3. Install screw to bottom of fuel tank bracket.

4. Tighten all three bolts.

CARBURETION





Fig. 62 - Install Carburetor on Fuel Tank (Typical)

Fig. 89 - Install Carburetor & Fuel Tank On Engine

Tool #

19391

Bottom

Screw

Assemble Carburetor

Install Welch Plug

1. Place a small amount of non-hardening sealant such

as Permatex® II or nail polish around outside edge of

welch plug) and place plug in metering or bottom

well.

2. With a 1/4" dia. (.64 mm), or larger, pin punch, set

welch plug with pin punch in center of plug.

Do not collapse plug, Fig. 76.

Assemble Fuel Pump

1. Smooth side of cup must rest against diaphragm,

Fig. 77. This prevents spring from cutting diaphragm.

2. When installing pump cover, tighten screws evenly in

staggered sequence to ensure a good seal.

3. Inspect all sealing surfaces for nicks or damages and

repair or replace as required.

4. Install Choke Shaft as shown in Fig. 78.

5. Install idle mixture screw and spring

Low Emission Carburetors Only

5a. Install pilot jet tighten until seated.

Install Choke Shaft & Plate

1. Place metal washer next to choke lever and then

foam washer.

2. Insert shaft assembly in carburetor body with stop

against remote control boss.

3. Insert choke plate in shaft with hole up and

indentations towards large welch plug, Fig. 86.

Note: On Choke-A-Matic® carburetors, be sure that

both ends of choke spring are engaged before

sliding shaft all the way into carburetor.

CARBURETION





Page 1 of 3

Fig. 76 - Install Welch Plug

Fig. 77 - Pulsa-Jet Carburetor

Fig. 78 - Install Choke Shaft & Plate

Pin Punch

Welch Plug

Cover

Pick-Up Tube

CapSpring

Pump

Diaphragm

Felt Washer

Metal

Washer Hole Up

Stamped Throttle Shaft

1. Press in new rubber throttle shaft seal with sealing lip

down until seal bottoms.

2. Place new foam seal on throttle and insert shaft in

carburetor body. Throttle plate is chamfered and has

an identification letter stamped on one side of valve.

3. Place throttle plate in carburetor with stamped letter

as shown in Fig. 85, and install throttle plate screw.

Install Fuel Pick-Up Tube

Slide new retainer clip onto brass pipe. Heat small end

of new nylon tube in hot water and push onto brass

pipe. Slide retaining clip onto nylon tube over groove on

brass pipe, Fig. 87.

CARBURETION





Page 2 of 3

Fig. 85 - Installing Stamped Throttle Shaft

Fig. 87 - Install Fuel Pick-Up Tube

Stamped

Letter

Assemble Choke-A-Matic® Linkage

Rotary Choke

1. Insert "Z" bend of Choke-A-Matic® linkage into same

hole as return spring.

2. Slide washer on the end of linkage and then slide

Choke-A-Matic® lever onto shaft.

3. Install lever assembly and stop switch on

carburetor, Fig. 79.

Note: Hook small end of spring on spring post and

long hook in bottom hole of choke shaft, Fig. 80.

Slide Choke

1. To assemble, slip washers and spring over choke

link, Fig. 81.

2. Hook choke link through hole in choke slide. Place

other end of choke link through hole in speed

adjustment lever.

3. Mount lever and stop switch insulator plate to

carburetor.

Manual Choke

Note: Bottom tooth of choke shaft should engage top

tooth on manual choke lever, Fig. 82.

CARBURETION





Page 3 of 3

Fig. 79 - Assembling Choke-A-Matic® Linkage

Fig. 80 - Assembling Choke-A-Matic® Spring

Fig. 81 - Assemble Choke-A-Matic® Linkage

Fig. 82 - Choke Shaft Engagement

Return

Spring

Choke

Link

"Z"

Bend

Lever

Spring

Spring

Post

SpringStop

Switch

First

Tooth

First

Slot


Remove Throttle Plate & Shaft

1. Remove throttle plate screw and throttle plate, Fig. 63.

2. After removal of throttle plate, throttle shaft and dust

seal may be lifted out, Fig. 63.

Note: Some Pulsa-Jet carburetors have a throttle

shaft seal in addition to the dust seal. Remove,

discard and replace.

3. Remove idle mixture needle and spring.

Note: Low emissions carburetors use a pilot jet

instead of an idle mixture needle and spring.

Remove pilot jet.

4. Snap out choke plate and remove choke shaft.

5. Remove filter screen from well, when used.

6. With a modified 1/4 inch (3.9 mm) pin punch, remove

welch plug) from carburetor body, Fig. 65.

Note: DO NOT remove fixed jet.

CARBURETION





Page 1 of 3

Fig. 63 - Remove Throttle Plate (Typical)

Fig. 65 - Removing Welch Plug)

Fig. 74 - Remove Choke Shaft And Plate, Rotary Choke

Throttle Shaft

Throttle Plate

Throttle Plate

Phillips Head

Screw

Metal Washer

Felt WasherChoke Shaft


Remove Adjustment Needle & Seat

1. Remove needle to inspect.

2. Replace needle if needle is bent, grooved, or

broken, Fig. 66.

3. If carburetor is gummy or dirty, remove seat to allow

better access to metering holes.

Note: Do not change metering hole sizes. Use only

compressed air or solvents to clean metering

holes.


Pulsa-Jet

1. To remove screen housing or nylon pipe from brass

pipe, slide retaining clip up onto brass pick-up tube.

2. Cut end of nylon tube where tube connects to brass

tube and remove tube.

3. Slide off old retaining clip and discard, Fig. 68.

Note: DO NOT remove brass pipe.


Vacu-Jet

Nylon fuel pick-up tubes are removed and replaced with

a 6 point 9/16" socket, Fig. 69.

The fuel pick-up tube contains a check ball and a fine

mesh screen. To function properly, screen must be

clean and check ball free, Fig. 69. Replace pick-up tube

if screen and ball cannot be satisfactorily cleaned in

carburetor cleaner.

CARBURETION





Page 2 of 3

Fig. 66 - Mixture Needle

Fig. 68 - Remove Pick-Up Tube

Fig. 69 - Remove Nylon Fuel Pick-Up Tube

Replace

Good

Pick-Up Tube

Retainer Clip

6 Pt. Socket

Wrench

9/16"

Disassemble Fuel Pump

1. Remove fuel pump cover, diaphragm, spring and cup,

Fig. 71.

2. Inspect diaphragm for punctures, cracks and fatigue.

Replace if damaged. Inspect all sealing surfaces for

nicks or damages and repair or replace as required.

CARBURETION





Page 3 of 3

Fig. 71 - Pulsa-Jet Fuel Pump

SpringCup Diaphragm

Cover

Models 91200 92200, 94200


2. Move throttle (top) lever to idle position.

Note: On fixed adjustable control panels, bend tang

down to move throttle lever to idle position.

3. Move choke (bottom) lever to full choke position,

Fig. 60.

4. Use a T-20 Torx® driver to remove two (2) screws

holding control panel to fuel tank and carburetor.

5. Remove control panel and disconnect choke rod and

stop wire from stop switch (when used).

Models 80200, 82200, 90200, 91200 92200, 112200,

130200, 132200, 135200, 136200, 137200


2. Disconnect choke link from control panel lever,

when used.

3. Remove two (2) screws holding control panel and

remove control panel.

4. Disconnect stop switch wire from stop switch and

set control panel aside.

CARBURETION


Pulsa-Jet, Fixed Main Jet



Page 1 of 2



Choke Link

Screws

Remove Fuel Tank from Carburetor

1. Remove remaining screws holding fuel tank onto

carburetor.

2. Remove screw holding fuel tank bracket to cylinder

base.

3. Separate fuel tank from carburetor and remove fuel

tank gasket and discard.

4. Disconnect governor linkage and spring from

carburetor.

CARBURETION





Page 2 of 2

Fig. 62 - Remove Fuel Tank From Carburetor (Typical)

Gasket

Models 80200, 82200, 90200, 91200, 92200, 94200,

112200, 130200, 132200, 135200, 136200, 137200

Fixed jet Pulsa-Jet carburetors have been made in three

versions.

1. Current version is small well, bottom fixed main jet,

Fig. 58A.

Note: Low emission carburetors have a filter screen

surrounding the small well and are equipped with

a pilot jet which eliminates the idle mixture

adjustment needle. Non-emission carburetors

have an adjustable idle mixture screw.

2. Second version is small well, fixed side main jet,

Fig 58B

Note: These carburetors are equipped with a idle

mixture adjustment needle

3. Early version is large well, fixed side main jet,

Fig. 58C.

Note: These carburetors are equipped with a idle

mixture adjustment needle

CARBURETION





Fig. 58 - Pulsa-Jet Carburetors, Fixed Main Jet

A. Small Well

Bottom Jet

B. Small Well

Side Jet

C. Large Well

Bottom Jet

page 1 of 1 carburetion -...

Documents