The only difference is the throttle bore size and jetting, but the carbs are exactly the same in construction and what works for teardown and reassembly on one will work for the other.

 

Back in '03 when we bought our brandy new '04's, I had my wife drive the truck (pulling the trailer with our new toys) while I read the manual cover to cover. I love reading docs on new stuff (no matter what it is). I thought I had it all dialed in. It wasn't 'til much later during another read that I discovered the part in the owner's manual about a 'primer' on the carb. Meantime, we struggled with hard cold weather starts (with the usual carping about why something with the name "Arctic Cat" was so hard to start in 'arctic' weather). Then, while sitting in the warm house with an appropriate warm adult beverage, I was re-reading the manual just for grins and THERE IT WAS! The "NOTE" on page 46 about the primer pump and using it at "0" degrees.

So the next time out (and it wasn't "0" degrees, but darned cold anyway...), we tried this pump action and what a difference. They fired right up. This is not to say they run great right at start-up, but at least we can get them running. And like someone mentioned somewhere else, once they're up and running (and warm), the rest of the day they run great, even after shutting them down for a while.

So once again (like bear said in another post), reading the Owner's Manual does have its benefits. In my case, I just have to remember what I read... Duh.

 

I think I read that too.......
Havent needed it yet but it is there, I looked.

 

The Arctic Cat 400's are great for starting in the cold, -20 the other day and it fired right up with just using the choke.

However, I really long for EFI...

 

Alot of times, the problem can be traced back to an incorrectly adjusted mixture screw, or two, in the case of the 650. They are usually adjusted in a warm, dealership, and when its outside in the cold...its too lean.
If the primer dooesnt get it going, or it stumbles and pops, when cold, give the mixture screws a 1/4 to 1/2 turn richer (out). It makes a world of difference.

 

Good advice.

 

Okay...looking at the link to the carb http://www.brownsleisureworld.com/Pa...CARBURETOR.htm which screw would need to be turned out 1/4 -1/2 turn? I can tear a car engine to pieces and put it back together but when it comes to carbs, I want my fuel injection! Please give me a number for the proper screw, #16???

 

Just discoverd that my 400i carborator had the choke sticking and not moving fully in either direction. Noticed this as it became hard to start and has alway been very easy. I have been adjusting the mixture screws as it has been running rich and backfiring especially after I let off the throttle.

So my daughter and I removed the carb and took it apart and found the choke was not fully functioning. It had a white crusty buildup from water in the fuel I guess. We cleaned it all up and put it back together, readjusted the mixture screws and no more problems.

Definitely would check the carb settings and the choke operation. (as well as the air filter)

Engine needs Fuel, Air, Spark to run if one is missing or not correctly set it won't start.

SJ

 

I don't have a problem with my 650. I put the choke on all the way, give it a bit of throttle and crank. Usually fires up in 3-4 turns. Idle is a little rough at first. I have to let it idle with the choke on for a minute and then gradually take it off. If I don't it will stall but fires back up. It warms up pretty quick and runs fine after that.
It sits out in my non insulated storage building all the time, out of the weather but no heat.

 

My '02 AC 500i, is hard starting during cold weather also. It wasn't always hard starting but over time it's been touchy... I usually coke as 522 says and it starts up. Let her run 'til it starts to choke and go to half coke and it keeps up--most of the time. As I said, it wasn't always this cycle of events to start. Even in cold weather. Reading what you guys are saying has caused me to think back to when the quad was new and how well it did run to startup. One thing I did do was to pour one third of a bottle of fuel de-icer into a full tank of fuel once. That was because I had gone to Kentucky to ride with others and it got so cold there that most of the machines wouldn't start... Including the AC. At that time, I took the fuel line apart and blew it out with compressed air, waited for an hour and tried to start it again. Well, it was at least five degrees warmer outside and it did start. No more problems. But some of the other quads/dirt bikes wouldn't start. Now you've got me thinking about the coke plunger having water buildup. This make sense and I'm going to be looking at the prospect of that being the bug in the fuel system. I know guys that ride almost every manufacturer's machine that have this problem, come winter riding. I've never heard anyone say, they checked the coke plunger. All the rest have been tried with some success. Saturday will be a good day to test your theory. It's gonna be 8 degrees here in the morning. Sorry about the long winded post... Thanks everyone,
Chuck