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

What It Is

This is a red replacement primer bulb for the carburetor on small engines, used to purge air and draw fuel into the carburetor before starting. It fits a range of lawn mowers, trimmers, and other outdoor power equipment that use common Tecumseh, MTD, and Craftsman engines.

Fitment & Compatibility

Before buying, verify your engine’s model number and the old bulb’s shape/measurements. This bulb replaces OEM parts 694394, 4178, 494408, and 5084, and is commonly found on Tecumseh engines (e.g., LV148EA, LV195EA) and MTD/Craftsman mowers with those engines. Measure the bulb’s diameter (typically ~1 inch) and stem length to confirm it matches your carburetor’s primer port. It is an aftermarket part, not OEM, so check that the rubber is pliable and the stem fits snugly into the carburetor body without forcing.

Key Things to Know

• Quality: Users report it works well as a direct replacement, but some note the rubber may be slightly stiffer than OEM. It should last a season or two under normal use.
• Installation: Easy—just pop the old bulb out and press the new one in. No tools required, but clean the carburetor port first to ensure a good seal.
• Common gotcha: If the bulb doesn’t seat fully or leaks air, the engine won’t prime. Check that the stem is not too long or short for your carburetor.
• Compatibility tip: This bulb is not universal—confirm your engine uses the listed OEM numbers. It won’t work on Briggs & Stratton or Honda engines with different primer systems.

Should You Buy It

If your mower or trimmer uses a Tecumseh or MTD engine with a worn-out primer bulb, this is a cheap, easy fix. It’s a solid value at the price, but double-check fitment against your old bulb first—if the stem or diameter is off, it won’t work. Best for DIYers who want a quick, no-fuss repair.