2002 Arctic Cat 400i Hesitation

[ridinin55020]

I purchased a 400i 3 days ago, past owner was a family friend. Pick it up and seemed to run OK but did hesitate know and then. I got the machine home and the hesitation was very predictable. seems like after a run through the gears, slow down to turn around and it would have a large dead spot in the throttle, miss and then go fine. i have 2 quads and me and a buddy went out near to my property. a little off road and I needed full choke just to get home! carb was cleaned after initial hesitation was found. new intake tube was ordered due to cracks in it, i wrapped it in gorilla tape to see if it would help, no change. please helpl

[Senator]

I needed full choke just to get home!

I'm a 2stroke guy so jetting carbs is second nature to me while 4stroke stuff like valves, cams, and unnecessary electronics I tend not to be well versed in. I'll try to help where I can though.

Full choke should be giving it a great deal more fuel than it can handle, especially after you've been riding it awhile. If it's running well with the choke on:

...another circuit in the carb may be restricted and the choke is making up for it, or...

...the jetting is too lean and the additional fuel supplied by the open choke circuit is required to make up for it, or...

...it could be some 4 stroke thing that someone else will have to chime in about

[Ajmboy]

Have you checked the air filter? More than likely it's the carb though.

* Added manufacturer and issue to thread title.

[swampcat07]

I would check to see to make sure the needle in the carb operates and opens correctly. Sounds like some problems in mid throttle.

Also put a new plug in do a chop and see what color it is for the first 1/4 throttle.

Now that I am thinking about it make sure the fuel flows fine and the in line filter is not blocked if there is one.

[ridinin55020]

update: I have done the following, replaced air filter, replaced cracked air intake tube, installed inline fuel filter, tried adjusting idle fuel screw. no real notable changes. I have cleaned the carb 3 times ( with spray cleaner and air). I am a experienced auto mechanic and understand how this thing should work. here is the problem. seems to have no acceleration or motivation after a long hard run or after idling a while. other wise ok. it seems strange I need help.

[Ajmboy]

update: I have done the following, replaced air filter, replaced cracked air intake tube, installed inline fuel filter, tried adjusting idle fuel screw. no real notable changes. I have cleaned the carb 3 times ( with spray cleaner and air). I am a experienced auto mechanic and understand how this thing should work. here is the problem. seems to have no acceleration or motivation after a long hard run or after idling a while. other wise ok. it seems strange I need help.

Could it be a bad coil, plug? After it heats up maybe one of them start to fail?

[mikeexplorer]

Mine had a similar problem, at times only seemed like I was giving it 1/3 throttle. The diaphragm in the slide was bad, although visually looked fine.

Mike

[ridinin55020]

I may have to try that, I put on about 30 to 40 miles this weekend with my wife and kids ( 3 and 5 years old). the trial was rough and machine ran great mostly 2nd and 3rd gear running with subtle throttle inputs. machine never missed a beat however after a good hard 2nd threw 5th run banging threw the gears same thing. I did inspect the diaphragm on the slide and it looked ok. Dealer said like $70 for that slide and diaphragm. ouch! or maybe stop acting like a kid, it is a ute 400 only!