TyroBullmastiff 0 Posted May 5, 2017 Hi Everyone, We purchased a 2012 TRX400X that was running fine for a couple of days, then starting having problems cranking. We changed the spark plug & it ran great for a day (just playing around our property). Next day it wouldn't crank for anything, tried jumping it, still wouldn't catch. Had battery tested, it was ok. It had about 1/2 tank of gas, so we filled it up. It will now crank, but won't idle without giving it gas. If you let it idle, it will pop once, then turn off. Should we start with the carb? Anyone one know of a step by step guide to this? I'm downloading this manual today.....https://www.tradebit.com/filedetail.php/279289626-2005-2014-trx400ex-trx400x-sportrax-service-repair Our local shop is backed up for weeks! Any suggestions would be greatly appreciated! Share this post Link to post Share on other sites Like what you are reading? Please help us by sharing this content.