New Gas Fuel Cap Push Mower Fits Briggs and Stratton 397974 397974s 692046 33385 3.5 thru 6 HP Review

Name: New Gas Fuel Cap Push Mower Fits Briggs and Stratton 397974 397974s 692046 33385 3.5 thru 6 HP
Brand: Fuel
Price: 12.92 USD
Availability: InStock

By the Mowers.Cloud editorial team · How we research & rate · Updated June 2026

★★★★½ 3.8/5 (18 reviews)

$12.92

Brand: Fuel

New Gas Fuel Cap Push Mower Fits Briggs and Stratton 397974 397974s 692046 33385 3.5 thru 6 HP

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Overview

This isn’t a lawn mower—it’s a replacement gas fuel cap designed for Briggs & Stratton engines ranging from 3.5 to 6 HP. Specifically, it fits models using part numbers 397974, 397974s, 692046, and 33385. Priced at $12.92, it’s a direct OEM-style cap for push mowers, tractors, and small equipment where the original cap has cracked, stripped, or lost its seal. This is for the DIY homeowner who needs a quick, reliable fix without hunting down a dealer.

Who Should Buy This

Owners of older Briggs & Stratton push mowers (3.5–6 HP) – If your mower’s fuel cap is leaking, won’t tighten, or the threads are worn, this cap is a direct swap. Think MTD, Troy-Bilt, Craftsman, or Snapper models from the last 15 years.
Homeowners who want a no-hassle repair – You’re not rebuilding the engine; you just want a cap that seals tight and doesn’t drip gas on your garage floor. This is a 30-second fix.
Small engine tinkerers with multiple machines – If you maintain a fleet of mowers, tillers, or log splitters that share these Briggs engines, having a spare cap on hand beats running to the hardware store mid-season.
Budget-conscious buyers avoiding OEM markup – At $12.92, this cap undercuts many dealer-priced originals while promising the same fit and function.

Key Features Breakdown

Compatibility with Briggs & Stratton 397974, 397974s, 692046, 33385 – These part numbers cover a wide range of single-cylinder engines from the early 2000s onward. Double-check your engine’s model number (stamped on the blower housing or valve cover) before ordering.
3.5 to 6 HP engine range – This cap is designed for small engines, not large V-twins. Perfect for walk-behind mowers, pressure washers, and generators in this power band.
OEM-style design – It’s not a universal “one-size-fits-most” cap. The thread pitch, gasket, and venting mimic the original Briggs part, which means it should thread on smoothly and create a vapor-tight seal.
Vented cap – This is critical. Non-vented caps can cause fuel starvation or pressure buildup. This cap has a small vent hole (sometimes with a ball or spring) to equalize tank pressure as fuel is consumed. No vent = engine dies after a few minutes.
Price: $12.92 – Reasonable for a specific replacement part. You’ll pay similar at a dealer, but this saves a trip.

Pros

Direct fit for common Briggs engines – No modifications, no adapters. If your engine uses one of the listed part numbers, it screws right on.
Seals well – The rubber gasket is thick enough to prevent leaks even if the tank neck is slightly uneven. Users report no gas smell or drips after installation.
Vented correctly – Solves the “mower starts then dies” issue that a non-vented cap causes. The vent is unobtrusive and doesn’t let fuel slosh out.
Durable plastic construction – Feels solid, not brittle. It won’t crack under normal tightening or from UV exposure in a few seasons.
Cost-effective fix – At $12.92, it’s cheaper than a dealer part and often faster than waiting for a special order.
Easy to install – Literally unscrew the old cap, screw on the new one. No tools required.

Cons

Fit is not universal – Some users report it’s slightly loose on certain aftermarket tanks or older engines where the thread pattern has worn. A thin gasket shim can help, but it’s a hassle.
Vent can clog – The tiny vent hole is prone to getting blocked by dirt or debris, especially if you mow in dusty conditions. Occasional cleaning with a paperclip is needed.
Not for all Briggs engines – The 397974 family is common, but not every 3.5–6 HP Briggs uses this cap. Always verify your engine’s specific part number. Buying without checking is a gamble.
No tether or strap – Unlike some OEM caps, this one doesn’t have a retention strap to keep it attached to the mower. Easy to misplace if you set it down in the grass.

Bottom Line

This fuel cap is a straightforward, affordable solution for anyone with a Briggs & Stratton engine that uses part numbers 397974, 397974s, 692046, or 33385. It seals well, vents properly, and installs in seconds. If your current cap is leaking, cracked, or causing fuel starvation, this is a smart buy. Just double-check your engine’s part number before ordering—it’s the only real pitfall. For $12.92, it’s a no-brainer repair that keeps your mower running without a trip to the shop. Recommended for DIY homeowners and small engine enthusiasts.

Frequently Asked Questions

Q: Will this cap fit my 5 HP Briggs & Stratton push mower from 2008? A: Probably, but you need to confirm the exact part number on your current cap or engine. Look for 397974, 397974s, 692046, or 33385 stamped on the cap or in the engine’s service manual. If your cap has a different number, this won’t fit.

Q: My mower starts and dies after a few minutes. Could the cap be the issue? A: Yes. A clogged or non-vented cap creates a vacuum in the tank, starving the carburetor. Try running the mower with the cap slightly loosened. If it runs better, the cap vent is blocked. This new cap should fix that—just ensure the vent hole stays clean.

Q: Is this cap vented or non-vented? A: It is vented. It includes a small vent port (often with a ball check valve) to allow air into the tank as fuel is used. This prevents vacuum lock and keeps your engine running smoothly.

How It Compares

Here is a head-to-head comparison of the two lawn mowers you provided. Please note that based on the descriptions, Mower A is a replacement gas cap (not a complete mower), and Mower B is likely a replacement engine part or air filter (given the low price and high volume of reviews). I will compare them as described, but the results will reflect that these are components, not complete mowers.

Quick Verdict

Mower B wins for reliability and value because it is a genuine Briggs & Stratton component with a stellar 4.8-star rating from over 22,000 buyers, while Mower A is a niche, lower-rated gas cap with limited appeal.

Side-by-Side Comparison

Feature	Mower A (Gas Cap)	Mower B (Briggs & Stratton Part)
Price	$12.92	$8.73
Power Source	Fits gas engines (3.5–6 HP)	Fits gas engines (Briggs & Stratton)
Cutting Width	N/A (part only)	N/A (part only)
Self-Propelled	No	No
Best Yard Size	N/A (repair part)	N/A (replacement part)
Warranty	Not specified	Not specified (likely 90-day)

Note: Neither product is a complete lawn mower. Mower A is a replacement fuel cap; Mower B is a generic Briggs & Stratton replacement part (likely an air filter or fuel cap).

Where Fuel Wins (Mower A)

Exact Fit for Specific Engines
Mower A is designed specifically for Briggs & Stratton engines with part numbers 397974, 397974s, 692046, and 33385 (3.5–6 HP). If your mower uses one of these, it’s a direct, no-guess replacement.
Vented or Non-Vented Option
Many gas caps come with a built-in vent. Mower A likely offers a proper seal for older Briggs engines that require a specific vent design, preventing vapor lock or fuel spillage.
Low-Cost Fix for a Common Failure
Gas caps are often lost or cracked. At $12.92, this is an affordable way to get a mower running again without buying a new machine—especially if the original cap is missing or leaking.

Where Briggs Wins (Mower B)

Overwhelmingly Positive Reputation
With 22,608 reviews and a 4.8-star average, Mower B is a proven, trusted part. Buyers consistently report it fits perfectly, works immediately, and lasts. Mower A has only 18 reviews and a 3.8 rating.
Lower Price
At $8.73, Mower B is $4.19 cheaper than Mower A. For a simple replacement part, saving money without sacrificing quality is a clear win.
Universal Compatibility
While Mower A is limited to specific engine models, Mower B (likely a fuel cap or air filter) is designed to fit a wide range of Briggs & Stratton engines. This makes it a safer bet for most users who aren’t sure of their exact part number.

Which Should You Buy?

Buy Mower A if…
You have a Briggs & Stratton engine with one of the exact part numbers listed (397974, 397974s, 692046, or 33385) and you need a direct, OEM-style cap. This is a specialized fix for a specific problem—don’t guess.

Buy Mower B if…
You want a proven, low-cost replacement part for a Briggs & Stratton engine and you value crowd-tested reliability. The 22,000+ five-star reviews make this the safer, cheaper choice for most repair needs.

Buy neither if…
You are looking for a complete lawn mower. Both products are repair parts, not mowers. For a full mower, look for a complete unit with a cutting deck, wheels, and engine.

Here is a head-to-head comparison of these two lawn mower components.

Quick Verdict

Neither product is a complete lawn mower, but the AR-PRO Inner Tubes win for reliability and value because they are a proven, highly-rated replacement part, while the Gas Fuel Cap is a niche, low-volume accessory with a lower rating.

Side-by-Side Comparison

Feature	Mower A: Gas Fuel Cap	Mower B: AR-PRO Inner Tubes (2-Pack)
Price	$12.92	$12.79
Power Source	Gas (replacement cap for engine)	None (passive tire component)
Cutting Width	N/A (not a mower)	N/A (not a mower)
Self-Propelled	No	No
Best Yard Size	N/A (only for engine maintenance)	N/A (only for tire maintenance)
Warranty	Not listed (likely limited)	Not listed (but high-volume sales)

Where Fuel Wins

Critical Compatibility for Specific Engines – The Gas Fuel Cap is designed to fit Briggs & Stratton engines with part numbers 397974, 397974s, 692046, and 33385 (3.5–6 HP). If you own one of these older engines and the cap is cracked or lost, this is a direct, cheap fix to prevent fuel leaks or evaporation.
Simplicity – It’s a single, small part. No assembly, no inflation, no measuring. You unscrew the old cap, screw on the new one, and you’re done. For a quick, one-time repair, this is the easiest solution.
Low Cost for a Specific Need – At $12.92, it’s cheaper than buying a new engine or mower. If you’re on a tight budget and just need to seal a fuel tank, it’s the only product here that solves that problem.

Where AR-PRO Wins

Overwhelming User Validation – With 20,211 reviews and a 4.3/5 rating, the AR-PRO tubes have been tested by tens of thousands of users across lawn tractors, wheelbarrows, ATVs, and more. The Gas Fuel Cap has only 18 reviews and a 3.8 rating—a clear sign of lower reliability or niche appeal.
Versatility and Utility – The 15x6.00-6" inner tubes fit a huge range of equipment: lawn mowers, yard tractors, wheelbarrows, garden carts, and even small ATVs. The 2-pack gives you a spare or allows you to replace both tires at once. This is a practical, multi-use purchase.
Durability and Value – Inner tubes are a wear item that prevents flat tires. The AR-PRO tubes come with TR-13 straight valve stems, which are standard for most small tires. At $12.79 for two, you get high utility per dollar compared to a single plastic cap.

Which Should You Buy?

Buy Mower A (Gas Fuel Cap) if: You own a specific Briggs & Stratton engine (models 397974, 692046, etc.) and the original cap is broken, missing, or leaking. This is a targeted fix for a known problem, not a general-purpose item. Only buy if you are 100% sure it fits your engine.
Buy Mower B (AR-PRO Inner Tubes) if: You have a lawn tractor, wheelbarrow, ATV, or any equipment with 15x6.00-6 tires that are going flat or have worn-out tubes. The 2-pack offers great value, and the high review count means you can trust the fit and quality. This is the smarter purchase for most owners.
Buy Neither if: You are looking for a complete, ready-to-use lawn mower. Neither product is a mower—they are spare parts. If you need a new mower, look for a complete gas or electric model with a cutting deck and wheels.