DEF Dual Carburetor Rebuild Kit for Mikuni Super BN Twin Carbs — Fits Sea-Doo 38–46mm, Complete Gaskets & Jets

This DEF dual carburetor rebuild kit supplies the gaskets, O-rings, diaphragms, jets and hardware needed to refresh two Mikuni SBN-style carbs so they perform reliably after years of use. It’s assembled as a full rebuild package for both carburetors and engineered to match OEM Mikuni dimensions, making it a practical choice when restoring fuel delivery, eliminating leaks and returning throttle response to factory-like condition.

Which watercraft and carb sizes does this kit fit?

The kit was designed for Mikuni Super BN series carburetors commonly used across many Sea-Doo, Kawasaki Waverunner and similar models. It covers common bore diameters that the SBN family uses, so it works for a wide selection of model years and engine configurations.

• Covers Mikuni Super BN twin carbs in popular sizes (38–46 mm ranges).
• Compatible with numerous Sea-Doo model years from early 1990s through 2000s.
• Also suitable for many Kawasaki Waverunner and select Polaris models that use SBN carbs.
• Includes parts for a full rebuild of two carburetors—complete set except needle/seat.

What parts are included and what’s not in the box?

This kit contains the essential consumables and sealed components needed during a full overhaul of two SBN-style Mikuni carbs. It replaces worn rubber and gasket items as well as jets and diaphragm plates so you can reassemble clean, sealed carb bodies with correct internal tolerances.

• Gaskets, O-rings, diaphragms and seals sized for SBN twin carbs.
• Main and pilot jets, springs, clips, screws and small hardware for two carbs.
• Float chamber gaskets and other rebuild items—needle and seat are not included.
• Two complete kit sets—one for each carburetor—so both sides are matched.

How will installing this kit affect performance and reliability?

Rebuilding worn carbs restores airtight sealing and correct fuel metering, which reduces stalling, hesitation and poor idling without needing a full carb replacement. Properly installed rebuild kits typically improve throttle response and stability across rev ranges by eliminating vacuum leaks and worn diaphragm action.

• Eliminates common vacuum and fuel seepage points with fresh gaskets and O-rings.
• Restores metering accuracy by replacing jets and diaphragm components.
• Makes tuning and syncing across the twin carbs more consistent.
• Extends usable life of OEM carb bodies, avoiding costly replacements.

What should I know before I start the rebuild?

Carb rebuilding requires some mechanical experience, basic tools and a clean workspace to avoid introducing debris into fuel passages. Inspect floats, float needles and seats, and confirm jet sizes before final tuning; you may need to source needle/seat components separately if they are worn or leaking.

• Use carb cleaner and compressed air to clear passages before assembly.
• Verify float height and bench-test for leaks before reinstalling on the engine.
• Keep jets and small parts organized to ensure correct placement during reassembly.
• Needle and seat replacement may be required but are not included in this kit.

Who is this for: The DEF dual rebuild kit is aimed at DIY mechanics, marine technicians and restoration enthusiasts who own Sea-Doo, Waverunner or similar PWC models that use Mikuni Super BN twin carburetors. If you need to renew both carbs with OEM-spec gaskets, diaphragms and jets without replacing the carb bodies, this kit provides the matched parts needed to complete a professional-quality rebuild.