my friend sold his yz for this 05 artic cat 400 and it had been sitting for maybe a a year it ran barley (was garage kept i belive the whole time) anyways i figured bad gas and carb clean n maybe he can try n keep up wit me (lol not my rm250 is a beast) so when he brings it to me it hits a whoping 7mph when i take it for a ride. so today i finaly got him to come to my house so i can clean it (hes not exactly the wrench turning type) so i clean the carb blast the **** out of it with carb cleaner, sea foam and my 200 psi compressor love that thing. so the carb is spotless and i drained the gas ran some new gas through the tank and line then dumped it. then refilled the gas so i take it up the road and hit maybe 10-20mph. does this quad need 93 octane . and when i fixed the womens quad hers didnt want to run good until i put a new battery in it which i forgot to mention the battery is not shot but it doesnt stay charged for more then a few hours would that cause it to run like this but the lights work nice and bright but they dim when he uses the winch

 

is it possible that it could be the stator plate? also what does it do? does it spit and sputter? is the carb maybe set too rich? maybe throw in a new plug and also what kind of compression does it get? how hard of starting is it? and no it doesn't require 93 octane.

 

Check the wires comming out of the side cover from the stator. If you move them when it's running and it dies you have the same problem I had. If it is not running by moving them it probably will start.

The wires are comming out of the harness just outside of the side plate where they do a 90 degree bend. They come in contact with the side plate or each other and cause the engine to spit/sputter or just die.

Every one of these 400s have or will have this problem because Artic Cat used the wrong wire in the harness. To fix it you have to take off t he side cover and replace the stator assembly. Problem with that is you probably will have the problem repeat itself when the wires fail again. They shrink and the wire protrudes out at the 90 degree joint.

The other option is to coat and tape the wires that are protruding and it will work fine. Call me at 602-697-6555 if you have any questions.

 

even a 200psi compressor can fail to blow all of the crud out of the carb if you didn't try running something through the jets after taking them out you may have still missed getting them clear to where they will work you can use a thin piece of wire to run through them to make sure they are flowing no 93 octane isn't necessary as it isn't a high compression application not that the other guys don't have good suggestions but if it's been sitting in a garage I would look at the carb again first before moving on to other things simply because gas turns to gum in a carb when it sits for a long time.

wow, that's hard to read without proper punctuation, isn't it?

 

I had some rough running problems with my 05 AC 300 4x4, so took the carb apart, cleaned, even replaced the jets, needle valve and spring. About $15 for all the factory jets.

Anyway after 3 tear downs with the schematic in hand no parts were missing. turned the needle till it stopped then back either 1 full turn or 1/2 a turn, cant remember but its what a carb tech told me to do at AC.

After months of headaches, the machine would idle all day long perfectly, light smoke, give it gas it would bog down like its choked. i could slowly get thru all 5 gears but let off the gas and it would stall.

Eventually took it to the shop, $100 for a carb tear down, which that carb i would have eaten off of after i was done withit, it was the shiniest piece on the bike. Anyway he found a missing piece in the carb. If your carb is similar, it has the long needle that sits under the black diaphragm with a spring, where that needle goes down into the body it should have a small beveled piece that looks like a race in a bearing set. its made of aluminum i think. that needle should be perfect in that limiting the fuel giving it proper mixture, well with my small can of compressed air I blew it out and did not know it the first time i cleaned it. its the size of the smallest O ring u can think of. Its not part of the schematic at all. I hope this helps if u need more of an explanation Ill try, let me know.

my carb was a Keihn (or something like that)