Naraku 24mm CVK Carburetor - GY6 & 139QMB Big Bore

This Naraku 24mm CVK carburetor gives your compatible GY6 150cc or 139QMB 85cc+ big-bore build the airflow it needs to make the most of its setup. The constant-vacuum design pairs a vacuum-operated slide with cable-operated throttle control, while the included electric choke provides automatic cold-start enrichment. With its metal float bowl, diaphragm cover and accessible throttle linkage, it brings familiar CVK operation to a properly matched performance build.

Key Features

• 24mm CVK bore: Increased airflow for compatible GY6 150cc and 139QMB big-bore engines of 85cc or larger.
• Constant-vacuum operation: Vacuum-operated slide works with the cable-operated throttle butterfly.
• Electric choke included: Automatic enrichment for cold starts with a compatible electrical connection.
• Defined connection sizes: 32mm intake connection and 42mm air-filter connection help you match the installation.
• Serviceable jetting: Supplied with a #102 main jet and #35 idle jet; final tuning must suit the engine, intake and exhaust.
• No accelerator pump: CVK configuration without an accelerator-pump assembly.

Technical Specifications

• Brand: Naraku
• Part number: 137-67
• Manufacturer part number: NK200.06
• Carburetor type: CVK, constant vacuum
• Bore: 24mm
• Intake connection: 32mm
• Air-filter connection: 42mm
• Main jet: #102, M5 × 0.8 thread
• Idle jet: #35, M6 × 0.75 thread
• Choke: Electric, included
• Accelerator pump: None
• Throttle control: Cable-operated butterfly with vacuum-operated slide

Compatibility

Engine code or displacement alone does not establish a direct fit. Check the 32mm intake connection, 42mm air-filter connection, throttle-cable attachment, electric-choke connection and available space before ordering. This is not a general replacement for stock 50cc 139QMB engines. Supplied jet sizes are a starting point; adjust jetting and idle settings for your engine, intake and exhaust.

This product is intended for off-road use only. This product is not intended for use on public roads or land. Performance upgrades are considered racing parts and are not covered by warranty.

• 24mm CVK bore for compatible GY6 150cc and 139QMB 85cc+ big-bore engines
• Electric choke included for automatic cold-start enrichment
• Constant-vacuum slide and cable-operated butterfly; no accelerator pump
• #102 main jet (M5 × 0.8) and #35 idle jet (M6 × 0.75); final tuning required
• 139QMB requires a separate 24mm intake manifold; 32mm intake and 42mm air-filter connections

Brand: Naraku; Part number: 137-67; MPN: NK200.06; Type: CVK constant-vacuum carburetor; Bore: 24mm; Intake connection: 32mm; Air-filter connection: 42mm; Main jet: #102 M5 × 0.8; Idle jet: #35 M6 × 0.75; Choke: electric included; Accelerator pump: none; Throttle: cable-operated butterfly and vacuum-operated slide; 139QMB manifold requirement: 24mm manifold sold separately

Compatible carbureted GY6 150cc scooter engines; 139QMB / QMB139 scooter engines with 85cc or larger cylinders require a separate 24mm intake manifold; verify 32mm intake connection, 42mm air-filter connection, throttle cable, choke connector, hose routing and clearance; final jetting required; not a general stock 50cc replacement