Join Date: May 2012
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ATV: 2004 Arctic Cat 400 4x4
2004 400 4x4 Carb problems
First time post here I was hoping for a little help from some of the forum pros.
I have a 2004 Arctic Cat 400 Manual Transmission 4x4. A couple of years ago it started running poorly. No power at all, spitting and sputtering. I took it to the arctic cat shop and he said it was bad gas. He said he added stabilizer and fresh fuel ran it around and it ran great.
Jump ahead seven months, got ready to leave town for a poker run getting quads loaded up and once again same issues. Ran it up and down the road to try and clear it up. Got up to the run and my wife was riding it and it got worse no low end power spitting and sputtering. Back to the shop I asked the tech to check the carb out he said they are normally reliable and nothing ever goes wrong with them in his experience. Picked it up and he said it was all good, said he cleaned the carb found some crap in it, added a in-line filter. Once again got it home couple months later jump on it running terrible.
Two days ago I tore into it. Found the start jet hanging by about two threads. Disassebled it, cleaned it, blew it out, put it back on and it seems to be running fine full throttle and idling good. I set the pilot screw at two turns out. The problem is coming up from an idle it spits and sputters no power until you get above about half throttle. Seems to run better when cold gets worse when it warms up. Especially worse in low range. I checked the valve clearance it seems real close intake good, exhaust maybe a thousandth over hard to get a good measurement.
I notice the vacum piston flutters as it does this when I had the air cleaner box off. Bad vacum piston? Any thoughts and help would be appreciated.
Also one run up and down the road wot it just died flat. Sat for a minute switched to the reserve setting while cranking and it started back up. Should have been plenty of fuel in tank to run on normal position just might have been a coincident.