JLM MARINE Carburetor Rebuild Kit for Yamaha 40/50 HP (6H4-W0093-04) — gaskets, seals & floats to restore smooth idle

JLM MARINE's 6H4-W0093-04 Carburetor Rebuild Kit restores the essential gaskets, seals, and parts needed to refurbish Yamaha 40 and 50 HP outboard carburetors and recover reliable engine performance.

If your Yamaha P40, P50, C40 or C50 has become temperamental, rough at idle, or loses power under load, a worn or leaking carburetor is often the cause. This comprehensive rebuild kit replaces the factory part numbers 6H4-W0093-04, 6H4-W0093-03, 6H4-W0093-02 and the Sierra 18-7768 equivalent, supplying the gaskets, o-rings, floats and small components you need to refurbish 1989–2009 40 HP and 1989–2006 50 HP models.

How will this kit improve my outboard's running condition?

Replacing degraded seals and worn parts restores proper fuel flow and airtight seals inside the carburetor, which helps the engine breathe and atomize fuel more consistently. That means smoother idling, crisper throttle response and fewer hard-starts after storage.

• Includes gaskets and o-rings to stop vacuum and fuel leaks.
• Replaces small wear parts that affect jetting and float operation.
• Helps restore the correct air–fuel ratio for stable combustion.

Which Yamaha outboards are compatible with this rebuild kit?

This kit is designed specifically for Yamaha 40 and 50 HP carburetors used across P40, P50, C40 and C50 platforms. It covers model years commonly found on older boats, matching the OEM part numbers listed for accurate fitment.

• Fits Yamaha 40 HP models from 1989 through 2009.
• Fits Yamaha 50 HP models from 1989 through 2006.
• Direct replacement for OEM: 6H4-W0093-04 / 6H4-W0093-03 / 6H4-W0093-02 and Sierra 18-7768.

What components are included and what do they fix?

The kit supplies the common consumables that fail first in a carburetor: gaskets, seals, and small hardware. Replacing those parts addresses leaks, improper float height, and deteriorated diaphragms that cause flooding, stalling, or poor acceleration.

• Set of paper and rubber gaskets to reseal throttle and float bowls.
• O-rings and seals to prevent fuel and vacuum leaks.
• Replacement small parts (floats/needles where applicable) to restore correct fuel metering.

How difficult is the rebuild process for a DIYer?

Basic mechanical skill and common hand tools are usually sufficient for a carburetor rebuild. Clear workspace, carburetor cleaner, and patience for reassembly are key; if you are inexperienced, photos and labeling parts during disassembly make reassembly straightforward.

• Requires moderate DIY skill and basic tools (screwdrivers, pliers, socket set).
• Carb cleaner and a small parts tray recommended to keep components organized.
• Follow service manual torque and adjustment specs for best results.

Who is this for: Boaters, backyard mechanics, and marine technicians who own or service Yamaha 40 HP and 50 HP outboards and want an OEM‑equivalent rebuild kit to restore carburetor reliability without replacing the full carburetor. It’s ideal for seasonal maintenance, troubleshooting drivability problems, or preparing an older engine for reliable use on the water.