Bifdolf

Shadetree, i check timing and it was ok. Its a messy process but all was good. Not many hours on her as only used when hunting and around yard stuff.

Thanks for response. I'll replace plug and put fresh ethanol free gas in her. Hopefully its something simple. It seems the backfiring when letting off full throttle is a known problem with fuel management system i believe ive read. Will update when i get take these steps

My 2012 trx420fm fuel injection has always had the well known backfiring during deceleration. Recently it has started to misfire/backfire badly when applying any throttle in nuetral. It will stall if one attempts to ride. Latest sympton is it would turnover but not start. Verified the following: Fuel pump works Fuel injector replaced a few years ago Have spark Noticed when pulling plug, it was wet with fuel, and very black with carbon. Cleaned plug and it started but backfiring and missfiring got worse over a matter of minutes until it stalled. Pulled plug again and it had already started to foul and this occurred over of 10 minutes max. No way to get troubleshooting codes of trx420fm that im aware. Game plan is to start with fresh non ethanol fuel, rebuild/replace fuel pump/filter assbly, new injector. Ill apply jumper to bypass sensors to determine if those are bad. I know fuel management has been a problem with these but not sure how to procede. Any guidance would be great. Thanks in advance. Sorry for long post

My name is Brian House and I just joined the ATVHONDA group. I own a 2012 Honda Rancher TRX420FM. I look forward to learn from the collective knowledge of this group and contribute when possible. I live in central Virginia and use my Rancher for chores and hunting.