I recently ordered new plugs for my bike. The manuals lists CR8 as the type (NGK). I couldn't find those so I bought a CR8EB and CR8EIX from Rocky Mountain but the tops of the plugs wouldn't fit. The stock spark plug has threads and is smaller at the top, whereas these guys http://www.rockymountainatv.com/Product_Details.atv?pid=00039071 have a top that's solid and a few mm's larger than my stock plug. I cleaned the stock plug and probably have a few more miles on it, but I'm looking for solutions. TT YZ crew?