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Start ShoppingMIKUNI F4/042-185 Hex Main Jets - Precision Brass Fuel Jets for Carburetors
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Description
Upgrade your carburetor's fuel delivery system with MIKUNI's F4/042-185 Hex Main Jets. These precision-engineered brass jets deliver consistent fuel flow for enhanced engine performance and responsiveness.
Key Features
- Brass Construction: Durable, corrosion-resistant material for long-lasting performance in harsh environments.
- Hex Head Design: Easy installation and precise adjustment for optimal fuel metering.
- 0.130in Orifice: Equivalent to #185 size for accurate fuel flow calibration.
- Lightweight Build: Only 0.5 grams for minimal impact on engine balance and responsiveness.
Why Choose This Product
These main jets are specifically calibrated for MIKUNI carburetor main circuits, ensuring smooth throttle response and efficient fuel combustion. The hex head design simplifies maintenance while the brass material resists clogging and wear. Perfect for riders seeking precise fuel control and reliable performance in racing, off-road, and street applications.
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Upgrade your carburetor's fuel delivery system with MIKUNI's F4/042-185 Hex Main Jets. These precision-engineered brass jets deliver consistent fuel flow for enhanced engine performance and responsiveness.
Key Features
- Brass Construction: Durable, corrosion-resistant material for long-lasting performance in harsh environments.
- Hex Head Design: Easy installation and precise adjustment for optimal fuel metering.
- 0.130in Orifice: Equivalent to #185 size for accurate fuel flow calibration.
- Lightweight Build: Only 0.5 grams for minimal impact on engine balance and responsiveness.
Why Choose This Product
These main jets are specifically calibrated for MIKUNI carburetor main circuits, ensuring smooth throttle response and efficient fuel combustion. The hex head design simplifies maintenance while the brass material resists clogging and wear. Perfect for riders seeking precise fuel control and reliable performance in racing, off-road, and street applications.
| SKU | GME0F083EC |
|---|---|
| MPN | F4/042-185 |
| Brand | MIKUNI |
| Category | Jets |
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Featured Review
| Make | Model | Years |
|---|---|---|
| Various (Suzuki, Yamaha, Honda, Kawasaki) | Multiple 2-stroke and 4-stroke models with Mikuni carbs (e.g., Suzuki RM250, Yamaha YZ125, Honda CR250) | 1980-2025 |
Frequently Asked Questions
Fits most Mikuni VM, TM, BS, and HSR series carbs with main jet size #185. Check your carb's main jet size by removal.
Universal for both; used in powersports bikes, ATVs with Mikuni carbs. Size #185 common for mid-range tuning.
Use jet kit chart or dyno tune based on mods (exhaust, air filter), elevation, and temperature. Lean = smaller, rich = larger.
Hex jets easier to remove/install without special tools; same flow specs.
Installation Guide
Difficulty
Easy
Est. Time
5 min
Tools Required
- Small flathead screwdriver
- Jet wrench or hex key (optional)
Pro Tips
- Remove float bowl fully to access main jet. Clean jet and needle jet. Test plug chop after install to verify tuning.
Common Mistakes to Avoid
- Not cleaning carb passages before install
- Incorrect jet sizing for altitude/temp changes
Comparison vs Stock/OEM
Direct OEM replacement or upgrade for factory Mikuni carbs
Improvements
- Precision machined for consistent fuel flow
- Easier hex head installation vs slotted round jets
Considerations
- Precision sizing critical; not a 'one-size-fits-all' upgrade
Durability & Warranty
Expected Lifespan
Indefinite with proper tuning (jets rarely wear out)
Warranty
Limited lifetime from Mikuni against defects
Maintenance
Inspect/clean during carb service (every 10-20 hours)
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