Carburetor MXT RACING 19 mm Type PHBG red with 5 mm main jet oil connection vacuum connection

The MXT-RACING carburetor Type PHBG with a 19 mm passage is a universally applicable slide carburetor for two-stroke engines. It is frequently used in 50-cc and 70-cc setups when flexible adjustment of the air-fuel mixture is required. The design is based on the proven PHBG construction and supports maintenance and adjustments as part of typical tuning work.

Product features:

• Slide carburetor Type PHBG
• 19 mm passage for tuned two-stroke setups
• Designed for a 5 mm main jet
• Aluminum float chamber with maintenance screw
• Screw closure on the carburetor slide
• Oil connection available
• Vacuum connection available
• Manual starter operation via cable
• Color variant red

The equipment allows for targeted adjustment via main and pilot jets, as the carburetor is designed for M5 main jets and has defined starting values. The maintenance screw and screw closure facilitate access to the float chamber and slide without connecting every work step with complete disassembly. The oil and vacuum connections are relevant for setups in which separate lubrication or vacuum-controlled fuel systems are used, provided the connections on the vehicle are designed appropriately.

Technical details:

• Carburetor type: PHBG
• Design: Slide carburetor
• Passage: 19 mm
• Intake port connection width: 25 mm
• Air filter connection width: 32 mm or 38 mm
• Main jet thread: M5
• Main jet size: 75
• Pilot jet: 60
• Jet needle: W16
• Choke: manual via cable

The connection dimensions are crucial for the mechanical fit to the intake system, while the M5 main jet, pilot jet and needle type form the basis for fine tuning. If the carburetor is integrated into a suitable intake system and the jetting is adjusted to the engine and air filter configuration, the mixture preparation can be controlled. The manual starter operation must match the existing choke guide so that starting and warm-up behavior remain reproducible.

Vehicle and model compatibility:

• Universally applicable in two-stroke vehicles
• Suitable for classic mopeds, Simson vehicles and scooters
• Use dependent on intake port connection, air filter connection and choke guide
• No blanket vehicle assignment possible, as serial and modification states differ depending on the model

Assembly and application instructions:

• Assembly is possible with a suitable 25-mm intake port. The air filter connection should be checked for 32 mm or 38 mm. Oil and vacuum connections must be connected correctly. The main jet and needle position must be adjusted to the respective setup. After assembly, idle speed, throttle response and spark plug image must be checked. Careful tuning is required to ensure smooth engine running and a stable mixture formation.

For reliable tuning, the correct connection assignment is functionally relevant, as incorrectly connected or open vacuum and oil connections can cause disturbances in the fuel system or lean mixture. The main jet and needle position influence the mixture formation under load and in the partial load range and thus determine engine running and thermal stress. Checking the spark plug image supports the practical assessment of whether the jetting matches the configuration.

Note for checking before purchase:

• Before purchasing, check whether the intake port connection, air filter connection, choke operation, and oil and vacuum connections are compatible with the existing vehicle. The carburetor is designed universally and is not vehicle-specific.

Brief information: Carburetor - Installation, adjustment & tuning

Installation: Mount carburetor without stress, check intake port and gaskets for leaks, adjust throttle cable smoothly, ensure fuel supply (gasoline, oil and vacuum).

Basic setting: Mixture screw mostly 1.5 - 2.5 turns open, adjust idle screw for stable idle speed, always tune engine when warm.

Tuning:

• Main jet = Full throttle / high load
• Needle position = Partial load & acceleration
• Pilot jet = Idle speed & starting (does not need to be changed in most cases)

Check: Check spark plug image

• white = too lean
• black = too rich
• brown = optimal

Important: A new carburetor tuning is absolutely necessary after changes to the air filter, exhaust or cylinder.

About the manufacturer MXT

MXT is the powerful in-house brand of Heavy Tuned and stands for high-quality spare and tuning parts for motorcycles, scooters and mopeds.

As a reliable alternative to OEM parts, MXT offers a wide range of cylinder kits, carburetors and crankshafts to variomatic components, fairing parts and batteries. The products convince with solid workmanship, accurate quality and a strong price-performance ratio.

Ideal for drivers who are looking for durable spare parts and tuning parts for many vehicle models.