Discussion Starter · #1 ·
2004 rubicon 500. (Trx500fa) It will cold start and run PERFECT. I mean no smoke, no tics, idles absolutely beautiful. Rev it up perfectly. But after a few minutes it will start to sputter out and die. Trying to give it fuel makes it worse. If it does recover it’s fine again. But usually it dies and won’t start back unless it sits a while. & backfires when trying to start it back. Let it sit, starts perfect again. Brand new oem Honda carb, plug is getting great spark. Even when it sputters out, I took the plug out and had bright blue spark. I put volt meter on battery and it’s charging good which makes me think stator and regulator/rectifier is good. I first thought it was maybe a overheat problem but everything checks out good there I think.. Because as long as you stay riding it does fine it won’t die at all. Rode it enough for fan to kick on once. Ride around as long as you want pretty much as long as you don’t stop. Just when you stop it’ll eventually start sputtering out and die. Backfire when trying to crank. I thought maybe valves needed adjusted but they sound good can’t hear them at all and I don’t think they would’ve tightened over time. Older ones cdi would get hot and quit but I’m still getting spark. I’m lost man. Good gas, good flow from petcock to carb, & tank vent is clear. I’m stumped. It runs too perfect at first to have jumped time or something like that. No smoke, tics, nothing. Runs and sounds great, pulls hard. Just can’t stop… any help is greatly appreciated. Thanks for any advice.