EV-2012YFZ450

I had the same issue and took it to the dealer multiple times and they also couldn't replicate the issue. The solution I found was to take off the Air Box cover...the issue is that there isn't enough air. If that works then you can purchse a different filter like a bolt on one that doesn't require the air box cover. I can find the one I got and if that helps, but try to take the air box cover off and see if that does the trick. Good luck!

Thanks for the replies, it's carb not fuel injected. The shop adjusted the flow height yesterday thinking that might be the issue since its mostly having this problem on an incline. They keep saying they haven't seen this before so it's sort of a trial and error at this point. Who knows, I'm losing faith in them quickly.

Hope someone can help: I’m having the same issue with both of my new quads and I’m not sure what the solution is. Both quads are sputtering heavily when accelerating (regardless of gear) and now even having issues climbing any sort of hill even in 1st gear, it’s as though I was trying to ride it in to high of a gear…it just dies. Took it into the shop and they said they couldn’t replicate the problem, they thought maybe the chock wasn’t all the way in. That wasn’t the issue because I just took it out this past weekend and the same problem again. They performed a major service on the bike (Inspect & adjust valves, replace spark plugs, oil filter, inspect battery, etc etc). It’s having this problem more often in higher elevations (3k-5k) feet, but was even doing this out in the desert so it can’t only be an elevation issue. Dropped it back off at the shop on the way home…Anyone have any suggestions? Very frustrating