2005 Arctic Cat 400 Starting problem

[vncowboy 10]

Howdy,

Just got this outfit only has 230 mi. following issues encountered:

1) when cold start wont start unless i take air fltr off and restrict air intake w my hand then she will fire but have to thumb the throttle till she warms up >after warm easy start. runs like bat out of hell cold or warm w plenty of pwr. maybe?: elect choke...??? saw on other forum someone replaced w Buell carb used on HarleyI think w manual choke?? while idling when warm she occasionally pops. dont know if elect choke is working have tried lever on right side of carb but no effect (torn diaphram?) JUST GUESSING!!!!!

2) front cv boots cracked and need replace. ordered boots. when i take off wheel, brake cal., etc will the spline drive shaft just pull out from differential or is there a lock ring holding the inner knuckle to the diff. ?

Any help will be much appreciated.

[Whip 10]

vncowboy, Any time you have to hand choke something to me that would indicate no fuel getting to the motor via the fuel system. And being you say it only has 230 miles on it indicates to me that most likely it has set too long causing the fuel to go bad and clogging the fuel system. I would suggest pull the tank and give it a good cleaning add and or replace any inline fuel filters and if the problem still exists pull the carb and clean it thoroughly then add a rebuild kit and check for any cracked or damaged diaphragms. And if yours has a fuel pump I would also check the output of that as well. Hope This Helps!

[vncowboy 10]

Thanks much for ur reply. Couple questions:

1) how do I know if my atv is a 400 act or 400 fis?

2) how do I test functionality of auto choke electricly? Everything else is working as it should.

3) would it damage the carb/engine if I sprayed (sparingly) BG carb cleaner in the air intake as a last ditch effort before overhauling/replacing carb. I have already put a few oz of seafoam in the gas tank which actually did help a little bit?

4) any info on removing front axles from differential as noted in 1st post in this thread ?

Thanks for the help!!!!!!!!!!!!

[mikeexplorer 231]

Thanks much for ur reply. Couple questions:

1) how do I know if my atv is a 400 act or 400 fis?

FIS is "Fully Independent Suspension" if you have cv joints and two springs in the rear, it is an FIS model.

2) how do I test functionality of auto choke electricly? Everything else is working as it should.

It is not an electrical part, the warming of the engine shuts it off.

3) would it damage the carb/engine if I sprayed (sparingly) BG carb cleaner in the air intake as a last ditch effort before overhauling/replacing carb. I have already put a few oz of seafoam in the gas tank which actually did help a little bit?

Try a stronger dose of Seafoam, it may clear the problem up. I have done this with good results. I also add a dash of Seafoam every other tankful.

4) any info on removing front axles from differential as noted in 1st post in this thread ?

Here is a step by step guide with pictures. I used this guide myself

CV Boot replacement with pics - ArcticChat.com - Arctic Cat Forum

Thanks for the help!!!!!!!!!!!!

[vncowboy 10]

since last post been running fine after cleaning carb jets > last week started getting rough again, cleaned jets again and noticed dripping gas out of valve (off,on,reserve). thought it was loose gas line but when took off valve handle noticed gas dripping out of valve body. little metal washer behind cover plate doesnt appear to be compressing correctly. went down to hwd store got a o-ring put it behind valve plate then reinstalled 2 small screws > stopped leaking but cant turn valve handle because rubber o-ring gripping the plate. runs great now but if I dont keep eye on gas level (no guage) then ill be walking out of the Big Horn mtns. Any ideas.?