plugs
I just ran the NGK's last weekend cause everyone says their good plugs, after I had already been running the stock champions RN57YCC that it came with. Once I had installed teh NGK I could instatntly tell that it didnt idle quite as smooth, and after riding for the day, I noticed that I had lost about 100 to 150 rpms, I also noticed the engine didnt run as crisp either. I was reading a thread on here the other day about plugs and noticed that polaris engineer their motors and dynos them with teh Champion plug and alot of other people that had made posts on that thread said the same thing, that their sleds ran crappier with the NGK's. My sled ran much better with the champions and I have already put them back in.