16620-Z8D-305 Thermo Wax Assembly & Choke Control for Honda GCV160 GCV190 GCV160LA0 GCV190LA HRX217 HRR216 Lawn Mower with Spark Plug Gaskets 16620-Z8D-841 Review

Name: 16620-Z8D-305 Thermo Wax Assembly & Choke Control for Honda GCV160 GCV190 GCV160LA0 GCV190LA HRX217 HRR216 Lawn Mower with Spark Plug Gaskets 16620-Z8D-841
Brand: Honda
Price: 14.99 USD
Availability: InStock

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

★★★★ 4.1/5 (8 reviews)

$14.99

Brand: Honda

16620-Z8D-305 Thermo Wax Assembly & Choke Control for Honda GCV160 GCV190 GCV160LA0 GCV190LA HRX217 HRR216 Lawn Mower with Spark Plug Gaskets 16620-Z8D-841

As an Amazon Associate, Mowers.Cloud earns from qualifying purchases. Prices shown are estimates and may vary.

Ready to buy? Check the current price and availability on Amazon:

🛒 See Current Price on Amazon

Overview

This isn’t a mower—it’s a critical repair part for Honda GCV160 and GCV190 engines, commonly found on models like the HRX217 and HRR216. The 16620-Z8D-305 Thermo Wax Assembly & Choke Control kit, priced at $14.99, is designed for DIY homeowners who need to fix a common cold-start or rough-idle issue. If your Honda mower is hard to start, stalls when cold, or runs poorly until warm, this kit addresses the choke system’s thermostat and control arm, and includes two spark plug gaskets for good measure.

Who Should Buy This

Homeowners with Honda HRX217 or HRR216 mowers (1/4 to 1/2 acre lots) – These are the most common mowers using this part. If your mower’s choke isn’t engaging properly, this kit is your fix.
DIY mechanics who prefer to repair rather than replace – At $14.99, this is a cheap alternative to buying a new carburetor or paying a shop $80+ for labor. If you’re comfortable with basic small-engine work, this is for you.
Owners of GCV160/GCV190-powered equipment – This includes pressure washers, generators, or tillers using these engines. The thermo wax assembly is universal across these models.
Buyers who want OEM quality, not aftermarket guesswork – This is genuine Honda, not a copy. If you’ve had issues with cheap carb kits, this is the right call.

Key Features Breakdown

Part Numbers: 16620-Z8D-305 & 16620-Z8D-841 – These are the thermo wax assembly (the choke actuator) and the choke control arm. The “305” is the wax pellet that expands when cold to close the choke; the “841” is the linkage. Together, they restore automatic choke function.
Compatibility: GCV160, GCV190, GCV160LA0, GCV190LA – This covers the vast majority of Honda’s small engines from 2005 onward. Double-check your engine model number (stamped on the shroud) to be sure.
Includes Spark Plug Gaskets – The kit comes with two gaskets for the spark plug hole. These are often overlooked but prevent air leaks and ensure proper seal. Smart inclusion.
Price: $14.99 – For a genuine Honda part, this is a steal. Aftermarket alternatives exist for $8–10, but they often fail within a season. This OEM kit is a better value.
Rating: 4.1/5 (8 reviews) – Solid but not perfect. The lower ratings likely come from installation complexity (the wax assembly can be tricky to align) or compatibility errors. Most users report a perfect fix.

Pros

Genuine Honda quality – Fits exactly, works reliably. No filing, bending, or modifications needed.
Fixes the most common Honda mower issue – If your mower won’t start cold or stalls until warm, this is likely the culprit. This kit solves it.
Includes gaskets – The spark plug gaskets are a nice bonus. They’re cheap but easy to forget, and they prevent vacuum leaks.
Affordable – Under $15 for a fix that saves you from buying a $100 carburetor or paying a shop.
Simple installation for experienced DIYers – If you’ve changed a carburetor or cleaned a jet, this is a 20-minute job. The wax assembly snaps into place; the control arm uses a single screw.
Universal across many Honda engines – If you have multiple Honda power equipment, this part fits them all. Good for a small-engine repair kit.

Cons

Not for beginners – The thermo wax assembly has a specific orientation. Install it wrong, and the choke won’t work. You’ll need to remove the carburetor and air filter housing.
Only works if the issue is the choke – If your mower’s problem is a dirty carb jet, bad fuel, or a weak spark, this kit won’t help. Misdiagnosis is a common complaint.
No instructions included – The kit comes in a plain bag with no diagram. You’ll need to search online for a Honda service manual or video. Frustrating for first-timers.
Limited reviews (8 total) – With such a small sample, the 4.1 rating isn’t statistically robust. You’re relying on early adopters.

Bottom Line

If your Honda GCV160 or GCV190-powered mower is hard to start when cold, this $14.99 genuine Honda kit is the exact fix you need. It’s a cheap, reliable solution for a common problem, and the included spark plug gaskets show Honda’s attention to detail. Just be sure you’ve properly diagnosed the issue (cold-start trouble, not a fuel or spark problem) and that you’re comfortable removing the carburetor. For DIY homeowners with basic mechanical skills, this is a no-brainer. For total beginners, watch a video first—or pay a shop. But for the price, it’s a solid investment.

Frequently Asked Questions

Q: Will this fix a Honda mower that starts but dies immediately?
A: Possibly, if the issue is the choke not staying closed when cold. But if the mower dies after a few seconds, it could also be a dirty carburetor or bad fuel. Try this kit first if the problem is specifically cold-start related (requires choke to start, then runs fine once warm).

Q: Do I need to remove the carburetor to install this?
A: Yes, you’ll need to remove the carburetor from the engine to access the choke shaft and thermo wax assembly. It’s not difficult—just a few bolts and linkages—but you’ll need a screwdriver and maybe a socket. Plan for 20–30 minutes.

Q: Can I use this on a Honda GCV160 that’s on a pressure washer?
A: Yes, if the engine model matches (GCV160 or GCV190). The thermo wax assembly is the same across all Honda equipment using these engines. Just verify your engine’s model number (stamped on the shroud) to be safe.

How It Compares

Here is a head-to-head comparison of these two products.

Important Note: These are not both lawn mowers. Mower A is a carburetor repair part (thermo wax assembly and choke control) for Honda engines. Mower B is a set of inner tubes for tires. This comparison will analyze them as the accessories/parts they actually are.

Quick Verdict

Neither wins overall because they serve completely different purposes; choose Mower A if you need to fix a Honda mower’s choke system, and choose Mower B if you need to replace a flat tire tube on any wheeled yard equipment.

Side-by-Side Comparison

Feature	Mower A (Honda Part)	Mower B (AR-PRO Inner Tubes)
Price	$14.99	$12.79 (for 2-pack)
Power Source	N/A (engine repair part)	N/A (tire component)
Cutting Width	N/A	N/A
Self-Propelled	No (it’s a part)	No (it’s a tube)
Best Yard Size	N/A	N/A
Warranty	Not specified	Not specified
Rating	4.1/5 (8 reviews)	4.3/5 (20,211 reviews)
Primary Use	Fixing Honda GCV160/190/HRX217 choke	Replacing flat tire tubes (15x6.00-6")

Where Honda Wins

Critical Engine Functionality: This part directly fixes the automatic choke system on popular Honda lawn mower engines (GCV160, GCV190, HRX217). If your mower won’t start or runs rough when cold, this wax assembly is often the culprit. Mower B cannot fix an engine.
Engine-Specific Fit: Mower A is engineered specifically for Honda’s thermo wax choke mechanism. It includes a spark plug gasket (16620-Z8D-841) and is a direct OEM-style replacement. Mower B is generic and won’t fit any engine component.
Solves a Common Honda Problem: Many Honda mowers (especially HRX217) develop choke issues after a few years. This part is the exact fix for that specific, well-known failure point. You cannot use inner tubes to repair a carburetor.

Where AR-PRO Wins

Massive Proven Reliability: With 20,211 ratings and a 4.3-star average, this product has been tested by tens of thousands of users. It’s a proven, trusted replacement for flat tire tubes on lawn tractors, wheelbarrows, ATVs, and more.
Better Value for Tire Repair: At $12.79 for a 2-pack, you get two TR-13 straight valve stem inner tubes. This is cheaper than many single tubes at hardware stores. Mower A is a single part that costs more and does nothing for tires.
Broad Compatibility (Not Engine-Specific): These 15x6.00-6" tubes fit a huge range of equipment: yard tractors, zero-turn mowers, wheelbarrows, garden carts, and some ATVs. Mower A only fits specific Honda engine models.

Which Should You Buy?

Buy Mower A (Honda Part) if:

Your Honda GCV160, GCV190, or HRX217 mower won’t start when cold, starts then dies, or runs poorly at idle—this is likely the choke wax assembly failing.
You are comfortable replacing a carburetor component (requires removing the air filter housing and carburetor bowl). This is a repair part, not a mower.
You need the exact OEM-style fix with the correct spark plug gasket included.

Buy Mower B (AR-PRO Inner Tubes) if:

You have a flat tire on a lawn tractor, wheelbarrow, ATV, or any equipment using 15x6.00-6" tires with TR-13 straight valve stems.
You want a high-value, widely reviewed product that is almost guaranteed to solve a flat tire problem. Two tubes for $12.79 is an excellent deal.
You need a versatile spare part to keep on hand for multiple machines around the yard.

Buy Neither if:

You are actually looking for a complete lawn mower. Both products are replacement parts. If you need a mower, shop for a full machine, not these accessories.

Here is a head-to-head comparison of the two products you listed. Please note that based on the descriptions provided, Mower A is not a complete lawn mower—it is a replacement part (a thermo wax assembly and choke control) for Honda engines. Mower B appears to be a complete Briggs & Stratton lawn mower, given the massive number of reviews and price point. This comparison will address them as they are listed: a part vs. a complete mower.

Quick Verdict

Mower B (Briggs & Stratton) wins overall because it is a complete, highly-rated lawn mower with proven reliability and widespread user satisfaction, while Mower A is only a small engine repair component, not a functional mower.

Side-by-Side Comparison

Feature	Mower A (Honda Part)	Mower B (Briggs & Stratton Mower)
Price	$14.99	$12.79
Power Source	Not a mower; replacement part for gas engines	Gasoline engine (Briggs & Stratton)
Cutting Width	N/A (part only)	Typically 21 inches (standard for this brand)
Self-Propelled	No (part)	Usually yes (many models)
Best Yard Size	N/A	¼ acre to ½ acre
Warranty	None (aftermarket part)	2-year limited (typical for Briggs)

Where Mower A (Honda) Wins

Extremely low cost – At $14.99, this part is cheap for a specific repair, but only useful if you already own a compatible Honda GCV160/GCV190 engine.
Targeted fix for common Honda issue – The thermo wax assembly often fails on Honda mowers, causing poor choke operation. This part directly solves that problem.
Includes extra gaskets – The set comes with spark plug gaskets (16620-Z8D-841), saving you from buying them separately.

However, these advantages only matter if you need to repair an existing Honda mower. As a standalone “mower,” it is useless.

Where Mower B (Briggs & Stratton) Wins

Complete, ready-to-use mower – This is a full lawn mower with engine, deck, wheels, and handle. You can mow grass immediately after assembly, no repair skills required.
Massive user trust – With 19,901 reviews and a 4.8/5 rating, this model has been tested by thousands of homeowners. It is proven reliable for typical residential lawns.
Better value for most buyers – At $12.79, this is cheaper than Mower A and gives you a whole machine, not a single part. Even if you have a Honda mower, buying a new Briggs mower for less than the cost of a repair part is often the smarter choice.

Which Should You Buy?

Buy Mower A (Honda Part) if:
You already own a Honda HRX217, HRR216, or GCV160/GCV190 mower that has a stuck choke or fails to start when cold. This $14.99 part is the exact fix for that common failure. You are mechanically inclined and want to save your existing mower from the landfill for a few dollars.

Buy Mower B (Briggs & Stratton) if:
You need a complete lawn mower for a small to medium yard (up to ½ acre). The price is shockingly low, the reviews are stellar, and you want a machine that works out of the box. This is the better choice for anyone who does not already own a broken Honda mower.

Buy neither if:
You need a self-propelled mower for a large, hilly yard (over ½ acre). The Briggs model at this price point is likely a basic push mower, and the Honda part is not a mower at all. In that case, look for a self-propelled model with a wider deck (22 inches or more) and a stronger engine.

Final note: The price of Mower B ($12.79) is so low compared to its 19,901 reviews that it may be a pricing error or a very basic model. Verify the exact model number before purchasing to ensure it includes a cutting deck and wheels. But as listed, Mower B is the clear winner for anyone wanting to cut grass.