Regulators

& Vaporizers

Fuel Systems for LPG and

Natural Gas Engines

Mixers &

Carburetors

Product

Catalog

Mixers & Carburetors

Woodward’s fuel system products are easy to select

and easy to use. A broad selection of Streamline mixers, carburetors,

regulators, vaporizors, and fuelocks cover a wide range of gaseous

engine applications, from 50 to 400 horsepower.

Streamline™ N-VFF30 Series fuelock filters are

used with high-pressure LPG vapor or liquid

withdrawal systems where dependable fuel shut off

is required. The vacuum-operated lockoffs are

designed for minimal engine vacuum activation, and

the integrated filter removes foreign materials from

the fuel.

Streamline™ regulators and vaporizers are available

in a range of sizes and types to cover most propane

and natural gas fuel control requirements.

Streamline™ mixers are a simple, air-valve design

that draws fuel into the mixer consistently across the

engine operating range, from cranking to full load.

That consistency assures reliable starts, smooth

off-idle progression and repeatable performance even

under extreme operating conditions.

With the engine stopped, fuel is sealed off within the

carburetor as well as the converter and fuelock,

giving a triple seal for safety. The mixer is completely

self-contained. It requires no linkage or idle vacuum

line to the intake manifold, and allows tremendous

installation flexibility. We can add throttle body and

air horn to provide you with a complete carburetor

assembly, such as the N-CA55-500, N-CA100 and

N-CA125 Series carburetors.

Fuelock Filters

Regulators & Vaporizers

TABLE OF CONTENTS WOODWARD

phone: 847.967.7730 / 800.451.7040 fax: 815.639.5299 web: www.woodward.com/fsp

Fuel System Products

PRODUCT LINE OVERVIEW . . . . . . . . . . . . . . . .2-5

FUEL LOCKOFFS & FILTERS . . . . . . . . . . . . . . . .4-7

N -VFF-30 Vacuum Fuelock Filter . . . . . . . . . . . . . . . . . .4-5

Fuel Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-7

REGULATORS & VAPORIZERS . . . . . . . . . . . . . .8-30

N-LPR Vapor Regulator . . . . . . . . . . . . . . . . . . . . . . . . . .8-9

N-51 Vapor Regulator . . . . . . . . . . . . . . . . . . . . . . . . .10-11

N-PJ Vapor Regulator . . . . . . . . . . . . . . . . . . . . . . . . .12-13

N-H420-NG Vapor Regulator . . . . . . . . . . . . . . . . . . . .14-15

N-J Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-17

N-2001 Regulator/Vaporizer . . . . . . . . . . . . . . . . . . . . .18-19

N-E Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20-21

N-H420 Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . .22-23

N-H420 Turbo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24-25

N-S Regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26-27

N-L Regulator Repair Kit . . . . . . . . . . . . . . . . . . . . . . . . . .28

Model N-IMP Reduction Valve . . . . . . . . . . . . . . . . . . . . .29

Flow Capacity Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30

CARBURETORS . . . . . . . . . . . . . . . . . . . . . . .31-51

Model N-CA55-500 Series . . . . . . . . . . . . . . . . . . . . . .32-33

Model N-CA70 Series . . . . . . . . . . . . . . . . . . . . . . . . . .34-35

Model N-CA100 Series . . . . . . . . . . . . . . . . . . . . . . . . .36-37

Model N-CA 125 Series . . . . . . . . . . . . . . . . . . . . . . . .38-39

Model N-CA200 Series . . . . . . . . . . . . . . . . . . . . . . . . .40-41

Model N-CA225 Series . . . . . . . . . . . . . . . . . . . . . . . . .42-43

Model N-CA300 Series . . . . . . . . . . . . . . . . . . . . . . . . .44-45

Model N-CA475 Series . . . . . . . . . . . . . . . . . . . . . . . . .46-47

Custom Fit Carburetors . . . . . . . . . . . . . . . . . . . . . . . .48-51

COMPONENTS . . . . . . . . . . . . . . . . . . . . . . . .52-76

Throttle Components . . . . . . . . . . . . . . . . . . . . . . . . . .52-54

Air Flow Components . . . . . . . . . . . . . . . . . . . . . . . . . .55-56

Hoof Governors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

Century & Zenith . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

Primers & Thermostats . . . . . . . . . . . . . . . . . . . . . . . . . . .59

Model Microvac N-1501L Vacuum Safety Switch . . . . .60-61

Switches & Gauges . . . . . . . . . . . . . . . . . . . . . . . . . . .62-63

Hours Meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

Low Fuel Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . .65

Hose Components . . . . . . . . . . . . . . . . . . . . . . . . . . . .66-69

Brass Fittings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

Bulkheads, Inline Filters & Sealants . . . . . . . . . . . . . . . . .71

Tank Fittings & Accessories . . . . . . . . . . . . . . . . . . . . . . . .72

Tank Brackets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73-74

Warning Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75-76

FORKLIFT KITS . . . . . . . . . . . . . . . . . . . . . . .77-87

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77-78

Caterpillar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79

Clark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80-81

Datsun/Nissan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82

Hyster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

Komatsu/Mistubishi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .84

Toyota . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .85

Yale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

Universal Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87

TECHNICAL INFORMATION . . . . . . . . . . . . . .88-118

Typical Forklift Schematic . . . . . . . . . . . . . . . . . . . . . .88-89

Automotive Duel Fuel Schematic . . . . . . . . . . . . . . . . .90-93

Stationary Engine Schematic . . . . . . . . . . . . . . . . . . . .94-95

Stationary Engine Dual Fuel Schematic . . . . . . . . . . . .96-97

Standard Dual Fuel Wiring W/ Vacuum, Lift . . . . . . . . . . . .98

3-way Vacuum Control Solenoid Duel Fuel Operation . . . .99

Air-Valve Diaphragm Installation . . . . . . . . . . . . . . . . . . .100

Fuel Characteristics . . . . . . . . . . . . . . . . . . . . . . . . .101-102

LPG Fuel Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103

Carburetor Selection Chart . . . . . . . . . . . . . . . . . . . .104-105

Carburetor Position/Bolt Spacing . . . . . . . . . . . . . . .106-107

Fuel System Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .108

Preliminary Engine Inspection Before Conversion . . .109-110

Ignition Modifications for LP-Gas . . . . . . . . . . . . . . .111-113

Engine Starting Problems . . . . . . . . . . . . . . . . . . . . . . . .114

Maintenance Suggestions & Checks . . . . . . . . . . . . . . . . 115

Return Goods Authorization Procedures . . . . . . . . . . . . .116

Order Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117

Product Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118

PRODUCT LINE OVERVIEW CARBURETORS, REGULATORS & FUELOCKS

2

Typical LPG Fuel System (Items highlighted in boldface blue are shown on the diagram)

Vacuum Fuelock Filter The Streamline carburetion system

starts with the vacuum fuelock filter (VFF). When a slight

vacuum signal from the engine (2” of water column [W.C].) is

sensed by the VFF, the fuel is allowed to flow through a tenmicron

filter to the pressure regulator/vaporizer. When the

vacuum ceases, a spring force pushes on a lever and the

valve operating pin closes against the orifice, thus shutting-off

the fuel flow. Therefore, the vacuum fuelock filter has two

primary functions: (1) it prevents dirty fuel from reaching the

carburetor and (2) it shuts off the fuel flow automatically,

regardless of the ignition being on or off.

Pressure Regulator/Vaporizer Streamline pressure regulators

are categorized as two-stage, negative pressure,

regulator/vaporizers because they:

1. Reduce fuel pressure in two stages,

2. Meter the fuel output in relation to a negative

pressure signal (vacuum) from the carburetors, and

3. Convert the fuel from a liquid to a vapor.

The negative pressure signal from the carburetor acts upon

the secondary diaphragm, allowing atmospheric pressure from

the upper side to move the diaphragm down. This causes the

secondary seat to open; thus allowing fuel to progress from

the primary chamber of the regulator to the secondary

chamber. To assist in engine start-up, some regulator models

have a primer button. These regulators use engine coolant to

assist in vaporizing the fuel via a heat transfer process that

occurs in the vaporizing chamber.

Carburetors The air valve carburetors consist of a mixer,

throttle body and an optional air horn. The air horn enables

the connection of an air hose or air filter assembly. The

throttle valve controls delivery of the air-fuel mixture into the

engine intake manifold based on the operator’s command

(foot pedal).

The air and fuel are mixed at controlled amounts in the

mixer. The air valve spring pushes the air valve assembly

closed until vacuum from the engine causes the spring to

compress and release fuel. The vacuum signal is transmitted

to the air valve assembly via the communication passages on

the air valve assembly. The greater the vacuum draw from

the engine, the more the air valve spring is compressed and

allows a larger amount of fuel to flow and mix with the air.

The air valve spring begins to compress in the presence of 6”

W.C. of vacuum, and the maximum spring displacement will

occur with 24” W.C. of vacuum.

The air-fuel metering device, or mixer, is completely selfcontained.

It requires no linkage or idle vacuum line from the

engine intake manifold. This construction allows for great

flexibility in the assembly and service of

carburetors. The mixer has a replaceable air valve assembly.

Fuel systems using air valve carburetors provide triple safety

seals. When the engine is stopped, fuel cannot pass the air

valve because the air valve spring holds the air valve closed.

At the same time, neither the pressure regulator nor the

vacuum fuelock filter allows the fuel flow as there is no

vacuum signal from the engine.

SELECTION CHART WOODWARD

phone: 847.967.7730 / 800.451.7040 fax: 815.639.5299 web: www.woodward.com/fsp 3

CARBURETOR & REGULATOR SELECTION CHART

The chart below shows the Streamline carburetors and regulators that are available for specific applications. Simply match

your engine’s flow rate (CFM) and/or horsepower (HP) to the model of carburetor and regulator that best suits your needs.

Carburetor models are listed at the bottom of the chart under each set of vertical bars. Regulators, shown at the top of the

chart, are listed according to fuel type: natural gas (NG), compressed natural gas (CNG) and liquified petroleum gas (LPG).

Regulator models N-LPR, N-PJ, N-51, N-J, and N-S can be used with carburetors shown in the white area (left side of chart).

Regulator models N-H420, N-2001, N-EB, and N-H420 can be used with carburetors shown in the blue area (right side of

chart).

For Example: If an industrial engine has 200 CFM of air flow and runs on CNG, then the recommended carburetor would be

Model N-CA200 and the recommended regulator would be Model N-H420. Or, referencing horsepower, a 300 HP industrial

engine running on LPG would use carburetor Model N-CA-475 and any of the regulator Models N-2001, N-EB, or N-H420.

Note that this chart should be used for reference only. To determine the ideal fuel system components for your engine,

contact a Streamline application engineer.

N-CA55 N-CA70 N-CA100 N-CA125 N-CA200 N-CA225 N-CA300 N-CA475

600

550

500

450

400

350

300

250

200

150

100

50

0

200

400

Flow Rate (CFM)

Maximum Engine Power (HP)

Minimum Flow Maximum Flow - Industrial Maximum Flow - Vehicle

0

50

100

150

250

300

350

CARBURETOR AND REGULATOR SELECTION REFERENCE CHART

NG N-LPR

N-PJ

N-51, N-J, N-S

N-H420

N-2001, N-EB, N-H420

CNG

LPG

FUELOCK SPECIFICATIONS

A. Overall Height . . . . . . . . . . . . 49⁄32" (108.7 mm)

B. Overall Width . . . . . . . . . . . . . 41⁄2" (114.3 mm)

C. Overall Depth . . . . . . . . . . . . . . 23⁄4" (69.9 mm)

D. Front of Fuelock to Center of

Mounting Hole . . . . . . . . . . . . . 15⁄16" (23.8 mm)

E. Mounting Holes Center to Center17⁄8" (47.6 mm)

F. Mounting Hole Diameter . . . . . . . . . . . . . . 1⁄4-20

G. Back of Fuelock to Center of

Fuel Outlet . . . . . . . . . . . . . . . 17⁄16" (36.5 mm)

H. Back of Fuelock to Center of

Vacuum Port . . . . . . . . . . . . . . 11⁄4" (31.6 mm)

J. Air Valve Vacuum Port NPT . . . . . . 1⁄8" (3.2 mm)

K. Fuel Outlet NPT . . . . . . . . . . . . . 1