Main Jet for Keihin Style PB, PAB and CVK Carburetors- 4mm

Precision Tuning: Keihin Style 4mm "Small Round" Main Jets

Fine-tune your air-fuel ratio with these high-precision 4mm Main Jets. Designed for Keihin PB, PAB, and CVK series carburetors, these jets are the essential component for optimizing performance after installing a big-bore kit, exhaust, or high-flow air filter. These are "Small Round" (99101-116) style jets, featuring an M4x0.70 thread.

Technical Specifications

• Jet Style: Keihin Small Round (99101-116 Style)
• Thread Pitch: M4 x 0.70mm
• Dimensions: 7mm (Total Length) x 5mm (Head Diameter)
• Material: High-Grade Machined Brass
• Available Sizes: #75 through #130

Comprehensive Fitment & Compatibility

These 4mm jets are the standard for many OEM and aftermarket 50cc to 150cc carburetors:

Tuning Advice: Always start with a larger jet than you think you need and "jet down." Running too small (lean) can cause engine overheating and permanent damage. For a comprehensive guide, visit our Jetting Instructions Blog.

Note: Not compatible with Keihin "Large Round" (99101-393) or "Hex" (99101-357) styles. Please verify your jet dimensions before ordering.

Original Parts For Scooters SKUs 114-36-75, 114-36-80, 114-36-85, 114-36-95, 114-36-100, 114-36-105, 114-36-110, 114-36-120, 114-36-125 

• Keihin Small Round style (99101-116) — M4x0.70 thread
• High-grade machined brass for precise metering
• Available in 15 sizes: #75 through #130
• Fits OEM and aftermarket Keihin PB, PAB, NCV, CVK carburetors
• Not compatible with Large Round (99101-393) or Hex (99101-357) styles

Jet Style: Keihin Small Round (99101-116) | Thread: M4 x 0.70mm | Dimensions: 7mm length x 5mm head | Material: Machined Brass | Sizes: #75, #80, #85, #90, #95, #98, #100, #102, #105, #110, #115, #120, #125, #128, #130

Genuine Buddy 50 (stock #74) | Genuine Buddy 125/150 (stock #90) | Genuine RoughHouse 50 | GY6/139QMB 50cc & 150cc CVK carbs | Keihin PB, PAB, NCV, CVK 17-26mm | Select Honda, Yamaha, SYM 4-stroke with Keihin CVK