640259 Primer Bulb fits Tecumseh VLV126 VLV40 VLV50 VLV55 VLV60 VLV65 VLV66 VLX50 VLX55 TVS90 Engine TC-36045A Lawn Mower and Ring

What It Is

This is a replacement primer bulb (OEM equivalent part number 640259) designed to push fuel into the carburetor on small engines that lack an automatic choke. It fits Tecumseh VLV, VLX, and TVS series engines commonly found on walk-behind lawn mowers, snow blowers, and tillers.

Fitment & Compatibility

• Engine series – Confirmed fit for Tecumseh VLV126, VLV40, VLV50, VLV55, VLV60, VLV65, VLV66, VLX50, VLX55, and TVS90 engines. Cross-references OEM part 640259 and TC-36045A.
• Machine type – Lawn mowers and ring-style engine covers (the metal ring that holds the primer bulb in place). Not for engines with a separate primer button or electric primer.
• Check before buying – Verify your engine model number (stamped on the engine shroud or label). Measure the bulb diameter – this is a standard 1-inch rubber bulb. If your ring is cracked or missing, you may need a separate retainer ring (not included).
• Aftermarket vs OEM – This is a non-OEM replacement. Material and durability can vary; reviews are limited (2 ratings), so expect typical aftermarket quality.

Key Things to Know

• Installation is simple – Remove the old bulb from the retainer ring, push the new one in until it seats fully. No tools required for most mowers.
• Common failure – Old primer bulbs harden, crack, or collapse. If your bulb feels stiff or won’t pop back out after pressing, replace it.
• Check the retainer ring – If the ring is bent or rusted, the new bulb won’t seal. You may need a separate ring (often sold as a set).
• Bulk compatibility – This bulb fits many Tecumseh engines, but double-check your engine’s primer location (some use a plastic housing instead of a metal ring).

Should You Buy It

If your Tecumseh engine won’t start or requires many pulls, and the primer bulb is cracked, collapsed, or hard, this is the cheapest and easiest fix. It’s right for DIYers who want a quick, no-tools replacement. Skip it if you need an OEM bulb for a commercial mower or if the retainer ring is damaged (you’ll need a full primer kit).