694394 Carburetor Primer Bulb Fits 694394 4178 494408 5084 Lawn Mowers Parts (Red) 2 Pack

What It Is

This is a replacement primer bulb for small engines, specifically designed to fit carburetors on walk-behind lawn mowers and other outdoor power equipment. It delivers a fuel charge to the carburetor for easier cold starts.

Fitment & Compatibility

Before buying, verify your mower’s brand and model. This 2-pack (part numbers 694394, 4178, 494408, 5084) is a common aftermarket replacement for many Briggs & Stratton, MTD, Craftsman, and Troy-Bilt mowers with push-primer carburetors. Check the bulb diameter (typically ~1 inch) and the stem length (usually ~0.5 inch). If your original bulb is cracked, hardened, or missing, measure it against the included bulbs to ensure a snug fit. This is not universal—confirm your carburetor uses a push-on style bulb, not a screw-in or threaded type.

Key Things to Know

• Quality: Red rubber compound is flexible but may be slightly stiffer than OEM; it should soften after a few uses. Some users report it works fine for light-duty mowers but may split sooner than OEM on heavy-use machines.
• Installation: Simple—remove the old bulb (usually just pulls off), clean the mounting hole, and push the new one in until it’s seated flush. No tools required. Avoid using lubricants that might degrade the rubber.
• Common Gotcha: If the bulb doesn’t stay on or feels loose, the mounting hole might be worn or cracked. Replace the carburetor gasket or carburetor itself if the hole is damaged.
• Two Pack: Handy as a spare, but if one fails quickly, you have a backup. Store extras in a cool, dry place to prevent premature aging.

Should You Buy It

If you need a budget-friendly, quick fix for a failed primer bulb on a standard push mower, this 2-pack is a solid value. It’s best for occasional users who want a simple, no-fuss repair. For heavy commercial use or if your mower has a specific OEM-only carburetor, invest in a genuine replacement for longer life.