Mudder 4 Pieces 694395 Primer Bulb for Briggs and Stratton Lawn Mower Replacement for 5085 5085H 5085K

What It Is

This is a 4-pack of aftermarket primer bulbs (part number 694395) designed to replace the worn-out rubber bulb on Briggs & Stratton lawn mower carburetors. It’s used to manually pump fuel into the carburetor before starting, common on push mowers, riders, and small engines that have a primer system.

Fitment & Compatibility

Before buying, confirm your engine uses a Briggs & Stratton 694395 primer bulb (the OEM part number). This fits many Briggs engines, including models 5085, 5085H, and 5085K, but also works on other small engines with the same bulb size. Measure your old bulb: the bulb itself is roughly 1 inch in diameter with a 0.5-inch stem. Check that your carburetor has a primer button that presses onto this type of bulb (not a push-primer that’s integrated into the carb cover). It does not fit all Briggs engines—some use different bulb shapes or mounting styles. Always cross-reference your engine’s model number (stamped on the blower housing or valve cover) with the 694395 OEM part.

Key Things to Buy

• Quality: These bulbs are rubber and can feel slightly stiffer than OEM, but most users report a good seal and long life. The 4-pack gives you spares for future replacements.
• Installation: Very easy—pop off the old bulb, push the new one into the primer button, and snap the button back onto the carburetor. No tools required.
• Common gotchas: If the mower still won’t prime, the issue may be a cracked fuel line or a dirty carburetor, not the bulb. Also, some carburetors use a one-piece primer assembly—this bulb won’t work on those.
• Fitment check: Verify the primer button on your mower is a separate piece that clips onto the bulb. If the button is molded into the carb cover, this bulb won’t fit.

Should You Buy It

Buy this if you have a Briggs & Stratton small engine with a replaceable primer bulb and the old one is cracked, hard, or leaking. It’s a cheap, easy fix that restores starting reliability. Skip it if your carb uses a non-standard bulb size or an integrated primer assembly—in those cases, you need a full carburetor or primer kit.