88-3980 Fuel Cap Compatible with Toro And Other Brands Commercial Walk Behind Mowers,Commercial Z-Master Mowers

What It Is

This is a replacement fuel cap (part number 88-3980) designed for Toro commercial walk-behind mowers and Z-Master zero-turn mowers. It seals the fuel tank to prevent leaks and debris entry, commonly used on high-hour commercial machines.

Fitment & Compatibility

Before buying, verify these specifics:

• OEM cross-reference: Toro part 88-3980 is the direct OEM number. Aftermarket versions (like this listing) should match the same thread pitch and venting design. Check your current cap for the stamped part number.
• Model fit: Confirmed for Toro Z-Master (all models with 88-3980 cap), Groundsmaster 72-inch, and many Toro commercial walk-behinds (e.g., 30-inch, 36-inch, 48-inch decks). Not for residential push mowers.
• Measurement tip: Measure the cap diameter and thread pattern. The 88-3980 is typically a 1.5-inch diameter cap with coarse threads. If your cap is a different size (e.g., 1.25-inch), it won’t fit.
• Brand cross-compatibility: May fit some Exmark, Scag, or John Deere commercial mowers that use the same 88-3980 cap, but verify against your owner’s manual or existing cap.

Key Things to Know

• Venting: This cap is vented (allows air in to prevent vacuum lock). If you need a non-vented cap (for emissions or tank pressure), this isn’t it. Test after install: engine should run without fuel starvation.
• Installation difficulty: Easy—unscrew old cap, screw on new one. No tools needed. Takes 30 seconds.
• Quality concerns: With a 3.7 rating and only 9 reviews, some users report caps that are slightly loose or don’t seal perfectly. Check the rubber gasket for even seating. If it feels loose, add a thin O-ring.
• Price vs. OEM: At $12.88, this is cheaper than a Toro dealer cap (usually $18–22). If you need exact fit and warranty, OEM is safer. For a backup or budget fix, this works.

Should You Buy It

Buy this if you need a quick, low-cost replacement for a Toro commercial mower with a worn or lost 88-3980 cap and don’t mind a slightly lower fit tolerance. Skip it if you want a guaranteed, tight seal for a high-use machine—spend the extra $5–8 for an OEM Toro cap from a dealer.