The bikes only engine mods are a jet kit and a 3x3 mod, it runs excellent on the road but I noticed this problem when I ride off road especially through sand rollers. If I stand up off road and try to go fast and only if I stand up the bike falls on its face power wise, its like the cylinder is not getting spark. The second I sit back down the power is right back on like nothing happened. My best example is if you are on a riding tractor and lift your butt for a second the thing starts to stall and then sit down and its fine again. Is there something I need to disconnect, please help. The bike only has 180 miles and its basically brand new. And I promise I used the search button and could not find the answer. Thanks in advance.