1975 WheelHorse D180 spark plug question

[BMW1 42]

My son and I are new to this but can someone explain what the purpose of what my son and I are calling "spark plug adapters"  Not sure if that is what they are called.

I've never seen these before.  They are screwed into the head and then the spark plug is screwed into the adapter.  Included pictures

 

[gwest_ca-(File Mod) 10,513]

There are adapters to change the thread size or seat style but in your case the threads appear to be the same so why the need for an adapter?

Some compression testers have adapters but again if the threads and seat are the same why the need for an adapter?

Some plugs use a sealing ring or gasket and others have a tapered seat with no ring or gasket.

H10C or RH10C is the correct plug for the K482.

 

Garry

[oldredrider 2,547]

That is a spark plug extension. It is used to reduce fouling of the plug due to worn rings. 

[squonk 38,988]

12 minutes ago, oldredrider said:

That is a spark plug extension. It is used to reduce fouling of the plug due to worn rings. 

Yup It raises the electrode out of the combustion chamber to hopefully keep the oil mist off the plug

[N3PUY 1,031]

Spark Plug Non-Fouler Dorman sells them.   42009 SHARE:             Spark Plug Non-Foulers - 18mm Gasket Seat Description Specifications Technical Info Where To Buy Product Description Dorman offers a variety of Spark Plug Non-Foulers for a range of applications. All our Non-Foulers are constructed of high-quality steel for long-lasting durability. Corrosion-resistant design Gaskets included (where applicable) Available in a range of sizes Non-Foulers help protect spark plugs from damage

[BMW1 42]

Thank you everyone for your assistance.  My son and I purchased this D180 at a price I could not resist.  It had not been started for 1.5 years.  We finally got it started this weekend and noticed the tractor does smoke.  

So, I am going to assume previous owner put these on for worn rings?

 

Thanks again for the help.