Honda 16620-Z8D-305 Thermo Wax Assembly

Installed with no problem, started with first pull as advertised, arrived when they said it was coming in.

Fixed my mower problem.

If you have a Honda engine (in this case, a 4-5 year old mower with Honda engine model GCV160) and are stumped trying to figure out how your once reliable, 1 pull to start up engine now requires many more, hot or cold, or won’t keep running once started (to include rough running / surging) this part is commonly the culprit. This part has everything to do with the “auto-choke” design of the engine, but can affect running performance, too. They wear out/ fail pretty frequently.Before you take apart your carb or replace spark plugs, etc. , remove your air filter element and check to see if the carb air intake valve is fully closed (as it should be with engine cold as shown in my pic), or if it is stuck partially open.Inside this part is a wax compound that expands/contracts with engine heat, and controls a small pin-like rod in its center. The pin contacts part of the carb intake air valve control arm.Engine cold = pin retracted and permits air intake valve to fully close (aka full choke).Engine hot = pin extended and prevents choke from being on, which isn’t generally needed to restart a warm engine.These pins usually fail to retract and just plain get stuck in one position, creating havoc for all things choke, idle, and running related. In my pics, you can clearly see how the pin of the old one is just stuck extended out a bit. This mower made its way into my shop because it suddenly required 7-10 pulls to start and surged once running, when a few weeks earlier all was fine with it.Shop manual references using a thermal paste on the body of the new part when installing. I never have and never had issues. Pics I included should help those unfamiliar with the parts location on engine. Getting the old one out frequently requires use of a needle nose vise grip pliers and a fair amount of wiggling. The aforementioned mower also surged badly until fully warmed up, and occasionally thereafter. Upon replacement of this part, engine is back to 1 pull to start and no surging issues.

This helps for mower when it won't start. I still don't understand why this product has wax. Honda needs to modify.

I mean, it's hard to go wrong with genuine OEM Honda parts. I had actually bought this for my 15 year old GCV160 powered mower since I was putting a new OEM carb on it, might as well, right? Well, good intentions, but I didn't do my homework and it was actually wrong for my mower. However, as luck would have it, I found myself working on a much newer (~5 year old) GCV160 a week later, this part was a direct fit for that engine so it didn't go to waste after all. I can't knock any stars off the review because I didn't do my homework, and the part works fine in newer engine which it is made for.Moral of the story, do your homework. This is definitely 100% OEM replacement for many newer GCV160, but the auto choke design did change over the years and I'm not sure when it changed.

Fits perfectly

Products worked as described. Shipping was quick and timely.

Last year, my Honda mower wouldn't start after it had been running and the engine was warm. It would sputter at a very low idle for a few seconds, then die. If I would let it cool for an hour or more, it would start just fine. I bought this wax plug assembly, replaced the one in my mower with it, and it performed just perfectly.......until today, about a year later, now it is doing the exact same thing again. I would expect better from Honda. Not sure if I should buy the Honda part or gamble on a cheaper knockoff version.