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

What It Is

This is a 2-pack of aftermarket carburetor primer bulbs (model 694394) designed to replace the rubber bulb that draws fuel into the carburetor on small engines. It’s commonly used on walk-behind lawn mowers, particularly older Craftsman, Husqvarna, and Poulan models with Briggs & Stratton or Tecumseh engines.

Fitment & Compatibility

Before buying, verify your mower’s model number and carburetor type. These bulbs fit many Briggs & Stratton engines using part numbers 694394, 4178, 494408, or 5084. They are not universal—measure the bulb’s diameter (typically ~1 inch) and stem length (~0.5 inch) to match your existing primer. They work with standard push mowers, but not zero-turn or riding mowers with different fuel systems. Check your carburetor’s primer port shape (round vs. oval) as this bulb is round. If your mower uses a different OEM primer (e.g., 692318), this won’t fit.

Key Things to Know

• Quality: Aftermarket rubber may be stiffer or less durable than OEM—expect it to last 1-2 seasons in normal use.
• Installation: Push the bulb firmly into the primer port until it seats; no tools needed. If it’s too loose, use a small zip tie or adhesive to secure it.
• Common gotcha: The bulb can crack if over-tightened or exposed to ethanol-blended fuel. Use fuel stabilizer to extend life.
• 2-pack: Handy for spares or if you have two mowers with the same primer.

Should You Buy It

Buy this if you need a cheap, quick fix for a mower that won’t start due to a cracked or missing primer bulb and you’ve confirmed it fits your carburetor. It’s a solid budget option for DIYers, but if you want longer life or exact fit, spend more on an OEM part.