9 Months ago I purchased 2 (new) 2003 Arctic Cat 400 FIS 2x2s with manual transmissions. The quads are a new adventure for me, i.e. first time owner. They are ridden at 6500 to 7000 feet elevation. The problem I have noticed is that with a wide-open throttle, in 5th gear, they have a tendency to stumble a little bit. I am assuming carburetor jetting is the issue and have ordered the next size smaller jets from the local dealer. Does any one have any comments or guidance they could share on this. Secondly, where can I find an exploded view of the carburetor and a quality shop manual for these quads.
Thanks
Racersammy

 

For what it's worth, I picked up a 2004 Arctic Cat shop manual on CD from eBay for $7. I does not include the 650, but we both have 400's so it's fine.

I think a search with Google will turn up the 'physical' manuals, but they're upwards of $20-30. Good luck.

Also, check out Alpha Parts (http://www.alpha-sports.com/arctic_cat_atv_parts.htm) for an exploded view of your carb.

 

mrtommy, thanks for the info. EBay for a maual duh why didn't I think of that. Slapping my self on the forhead.
Thanks again

 

I live at 7300 ft and my 2004 400 FIS is jetted with a 130 main, runs great.

 

Smallcat, thanks. I was under the assumption that 150 was the factory installed size and I would try 147's or 145's in the 2 bikes. I guess I need to re-think this before buying any. The spark plugs definitely have some carbon build up. I assume you are not having any problem running too lean?
Thanks
Racersammy

 

No problems running lean. The dealers around here in the mountains rejet all the machines for high altitude before they sell them. General rule of thumb is 10% smaller than sea level jet.

 

I have no idea what our 400's came jetted with, but I can tell you we've been to 9300 feet and had little power loss. You can tell the difference but it's not something we can't deal with. Carson City sits about 5000 feet. All our riding has been between 4500 and 8000 feet generally, and we can't complain. I've thought about getting ours dyno'd (just to see what they're putting out), and then re-jetted if need be, but haven't gotten around to 'allotting' the money for it.

 

Jetting: Smallcat you are right on about jet size. 10% is a good rule of thumb as a starting point. I ride at >7500' and took my 300 4x2 from the factory jet of 140 to a 127. It runs sweet, very sweet. Nicer than my 500 actually. I took my 500i 4x4 Auto from a 148 to a 135 and it runs excellent, but not as good as the 300. I'm just talking about how the engine runs, not the fact that the 500 has more power, which, of course it does. The plug on each machine looks good, but I still need to tinker with the 500 - don't want it too lean. If you think about it, the black on carboned plug is really unburned fuel. Unburned fuel is fuel that is wasted and not turned into power. Both my machines ran fine at the higher altitudes prior to rejetting, but the fuel econ was ugly - still is on the 500...but, hey it's a 500. I watch the plugs closely. Fortunately, a 4-stroke is more tolerant of jetting vs. altitude than a 2-stroke. Also fiddled with the float settings - I'm getting there.