Thank you, sir! So, the upgrade is switching to an iridium plug? Is it a different heat range? I know mine was running rough and difficult to start, so I pulled the spark plug. It was fouled, so rather than clean and replace it, I changed it out for a new plug. I gapped it according to the manual, and it runs much better, and starts quicker. It's the same plug, just a new one.
I thought that iridium and platinum plugs were for extended use? Personally, I don't like them. I use NGK V-groove plugs in my vehicles. The UTV gets a standard copper core plug. My reasoning for that choice is a combination of price and performance. Have you ever tried to remove a spark plug that's been in a head for 100,000 miles? It's lots of fun, let me tell ya. I have also seen the platinum tips disappear, causing a poor performance issue. True, I may spend more on plugs over the life of the vehicle, but I don't get plugs that are nearly impossible to remove, either. Platinum isn't as good a conductor as copper, either. I would think that would be harder on the coil, since the resistance is greater. I don't know about the conductivity of iridium, but I do know it costs considerably more than the copper plugs do.