My brother has an 03 Arctic cat 400 4x4 and is having a problem after driving in water just above the tires. Ever since he went through the water when you hit about fifteen miles an hour or gun it from a start it starts sputtering just like the rev limiter does in reverse. There is no water in the air box or belt case, But I assume something got wet. Any ideas what to look for ?? He has went through this type of water before and has never had a problem. TIA for any help.

 

steam off the engine is being sucked in the air box , and as soon as you get out of the water the sputtering stops? That is what I founded on mine.

 

Bobmack, It has been two weeks since he was in the water and it is still doing it. I noticed that what looks like it is the CDI by the right rear wheel, Could something have gotten wet inside it ??

 

I had a problem too while traving thru water. It was only about bottom of the floor rests and I was going slow but it sputtered alittle then die. I hit the starter button and it was all good. Going back thru the creek, same thing. I think with mine, it was a electrical problem. It happen every time and even mud puddles that was only 8 in deep.
2003 400 I 4x4

 

Could it have just been a cooincidence, going thru the water? It should have dried out by now. Have him check the spark plug and boot, and put dielectric grease on the inside of the boot when he reinstalls it, this will keep the spark from grounding out in deep water.
Check the other connectors, especially the one coming from the stator side of the motor, it may have moisture still in it, and if its dry, add some dielectic grease there too, to keep it from shorting out in the future.
If the plug and cap look good, then its probably fuel related. Maybe when it went thru the water, the bouncing and such stirred up the setiment in the float bowl, and one of the jets sucked it up.
When it acts up, have him pull the choke full on, and if it runs better, then its probably a dirty passage somewhere in the carb. Pulling the choke on, will add the starter jet to the mixture and will make it richer.

 

Not sure if this will help, when I got my 03 400 home and took it out for the first ,I noticed some problems .
#1 exhaust vibration ,easy fix
#2 loose coil ,not wire "coil"
#3 loose battery cables
Nothing critical just over looked at the factory ,I suggest going over the hole thing ,seal up all electrical connection with dielectric grease , water can cause funny things to happen.