I have a 2014 570 SPORTSMAN with 350 miles on it… there is a bridge closed near my hunting place that gives me a long stretch of highway with. No traffic on it. Gave me the perfect opportunity to see what it will top out at. 64mph for me. Anyways, on the return trip it started backfiring and losing speed rapidly. So i let off and it died. Tried restarting it to no avail. I thought I killed it. I decide to take the side panels off and change the spark plug… The spark plug wire had vibrated loose. Reattached and ran just like it was before. WHEW!!!! But I did learn one thing, the spark plug adapter that comes with the kit will not go in the recessed hole because it hits the gas tank. Not easily anyways. So be prepared, take an actual Plug socket and a socket wrench with you.