5-Pack Primer Bulb 694395 for Briggs and Stratton Lawn Mowers - Replacement for 5085 5085H 5085K - Durable Rubber Primer Bulb for 3.5-6.75 HP Quantum and 625-875 Series Engines

What It Is

This is a pack of five replacement primer bulbs (part number 694395) for Briggs & Stratton lawn mower engines. The primer bulb pushes fuel into the carburetor to help start cold engines, and it’s designed for 3.5–6.75 HP Quantum and 625–875 Series engines.

Fitment & Compatibility

Before buying, confirm your engine’s model number—look for a metal tag on the engine shroud or near the spark plug. This bulb fits Briggs & Stratton engines in the Quantum, 625, 675, 725, 775, 800, and 875 Series. It replaces OEM part numbers 694395, 5085, 5085H, and 5085K. It will NOT fit older non-Quantum engines or engines with a different primer bulb design (e.g., larger or threaded bulbs). Measure the bulb’s stem diameter (about 0.25 inches) and overall diameter (about 1 inch) to compare with your existing bulb. This is an aftermarket part, not OEM, but it matches the original specs.

Key Things to Know

• Quality: Users report good durability and a tight seal. The rubber is firm but flexible, similar to OEM.
• Installation: Easy—just pull off the old bulb and push the new one onto the carburetor nipple. No tools needed.
• Common gotcha: If the engine still won’t start after replacement, the carburetor or fuel line may be clogged. The bulb alone won’t fix that.
• Pack size: Five bulbs mean you have spares for future replacements or multiple mowers. Store extras in a cool, dry place to prevent rubber dry-out.

Should You Buy It

Buy this if you have a Briggs & Stratton Quantum or 625–875 Series engine and need a quick, cheap fix for a cracked or collapsed primer bulb. It’s a solid value for the price and includes spares, but skip it if your engine is older or uses a different primer design—check fitment first.