Mikuni Dual Carb Rebuild Kit for Super BN 38–46mm – Twin OEM Gaskets & Diaphragms

Genuine Mikuni dual-carburetor rebuild kit engineered to restore two Mikuni Super BN carburetors (38/40i/44/46mm) to factory-spec performance.

This OEM Mikuni SBN twin carb rebuild kit supplies a complete selection of gaskets, diaphragms, screws, jets, and rubber components required to overhaul two matching carburetors for a long list of personal watercraft and small marine engines. The package includes the exact individual rebuild kit parts pictured and fits the Super BN family of Mikuni carbs; needle/seat assemblies are not included. Use it when you want accurate replacement parts from the original manufacturer instead of aftermarket knock-offs.

Which machines and years will this rebuild kit fit?

The kit is designed for Mikuni Super BN carburetors in multiple 38–46mm sizes and supports a wide range of Sea‑Doo, Yamaha, Polaris and other watercraft models across the 1990s and early 2000s. Always verify your carburetor model (Super BN) and diameter before ordering to ensure compatibility. If you run two matching Mikuni carbs on your intake, this twin kit supplies both sides so you rebuild both simultaneously.

• Sea‑Doo models: SP, SPI, SPX, HX, XP, GS/GSI/GSX, GTI, GTS, GTX, Challenger series (1992–1999 ranges)
• Yamaha models: SuperJet, WaveRunner family, Wave Blaster, Wave Raider, VXR series, XL/GP/LS/AR models (1990s–2005 coverage)
• Polaris and other makes: SL/SLT/SLX series and several Tigershark variants (specified years)
• Fits Mikuni Super BN carbs in 38mm, 40i, 44mm and 46mm sizes

What parts are included and what is excluded?

This twin kit contains complete rebuild components for two carburetors: gaskets, O‑rings, diaphragms, accelerator pump parts, float bowl seals, and small hardware. The rebuild set supplies the wear items you typically replace during a service to stop leaks, restore fuel metering, and eliminate sticking slides or pumps. Note that the needle/seat assemblies are explicitly not included, so plan to source those separately if your application requires them.

• Included: gaskets, diaphragms, jets, float bowl seals, springs, O‑rings, hardware for 2 carbs
• Excluded: needle/seat valve assemblies — purchase separately if worn
• Exact kit contents per carb are shown in the product photos provided

How does replacing these parts improve engine performance?

Replacing worn rubber and gasket components stops vacuum leaks, prevents fuel seepage, and restores consistent diaphragm and pump action so fuel metering returns to intended behavior. A matched rebuild on both carbs helps synchronization, smooth idle, and throttle response across the full rev range. While this kit does not retune jets, it provides the stable sealing and mechanical operation needed for accurate tuning and reliable operation.

• Eliminates vacuum leaks that cause rough idle and poor throttle response
• Restores diaphragm and pump function for consistent fuel delivery
• Makes carburetor synchronization and jetting adjustments repeatable

How should I use the twin kit during a service?

Perform a full teardown of both carburetors and clean all metal passages before installing the new rebuild components to avoid contamination and premature wear. Replace all rubber parts from the kit, rebuild each carburetor identically, and then sync the carburetors per manufacturer procedure. Check float heights and inspect needle/seat condition before reassembly; replace needle/seat if you observe leaks or wear.

• Clean carb bodies and passages thoroughly prior to installing kit parts
• Rebuild both carbs identically and verify float height settings
• Synchronize carbs after reassembly for balanced performance

Who is this for: This genuine Mikuni twin rebuild kit is intended for DIY mechanics, professional marine technicians, and owners of Sea‑Doo, Yamaha, Polaris, and similar watercraft that use Mikuni Super BN carburetors. Choose it if you want OEM-quality replacement components to restore sealing, diaphragm action, and overall carb function on two-matched carbs during a comprehensive service.