GENUINE OEM TECUMSEH PARTS - PRIMER RPR KIT 640351

What It Is

The Tecumseh Primer Repair Kit 640351 replaces the worn rubber primer bulb and related components on small engines that use a push-button primer system. It’s designed for walk-behind mowers, snow blowers, and other equipment powered by Tecumseh engines (typically 3–10 HP).

Fitment & Compatibility

• Check engine model: Works with Tecumseh engines using primer part numbers 640351, 640351A, or 640351B. Look for a stamped model number on the engine shroud or near the spark plug.
• Not universal: Does not fit Briggs & Stratton, Honda, or other brands without adapter kits. Verify your primer housing accepts this specific rubber cup and spring design.
• Measurements: The kit includes a primer bulb (approx. 1-inch diameter), spring, and retainer clip. Measure your existing bulb diameter to confirm.
• OEM vs aftermarket: This is genuine Tecumseh, so it matches factory specs exactly. Aftermarket kits may vary in rubber hardness or spring tension.

Key Things to Know

• Quality: OEM rubber is formulated to resist ethanol-blended fuels and cracking. Aftermarket bulbs often fail within a season.
• Installation difficulty: Easy (15 minutes). Remove the old bulb, clean the housing, press in the new bulb, and secure with the clip. No special tools needed.
• Common gotcha: If the primer hose is cracked or clogged, replacing only the bulb won’t fix hard-starting issues. Check the hose and fuel line for kinks or debris.
• Spring orientation: The spring goes under the bulb, not on top. Installing it backward prevents the bulb from snapping back.

Should You Buy It

Buy this if your Tecumseh engine’s primer bulb is cracked, hard, or torn, causing fuel not to squirt into the carburetor. It’s a cheap, easy fix for a common problem—skip it if the primer hose or carburetor gaskets are damaged, as those need separate repair.