You want the Plain-Vanilla  NGK #4339 DCPR8E, Standard Nickel Plug WITH the Removable Terminal Nut.

Or the Irridium Version at 3x the price.

BLYB = Retail Blister Package

IX = Irridium

KP,KC = Multi Electrode 

Solid = Non-Removable Terminal Nut

- - -

Interesting that all the Multi-Electrode versions have Non-Removable Terminal Nuts.

Other than that, they are 1/3 the Rotax price.

Glenn Martin wrote:

My IS came with NGK DCPRE spark plugs and have worked very well they cost about $4 each.

Recently ROTAX have decided to say you must use their own which are 10X the price.....

 

IMHO this is BS....

 

but what do others say ?

 

NGK forbids the use of their products in aviation so Rotax had to change suppliers.

The new supplier had to found, and they had to agree to aviation use. Of course, this raises their cost, and with such low volume we have in aviation, the price demanded was high.

Who is the new supplier?

Bill, What is the best supplier to choose in order to avoid Chinese counterfeit plugs?  There is some discussion of these on YouTube automotive channels, with examples demonstrated.  Thank you!  

If you choose to use NGK plugs then any automotive store usually has them or can get them. You see these plugs in motorcycles and other engines.