I took my new 400 4x4 LE into the dealer to adjust the shifter linkage got to talking about engine mods and he said it would be a huge waist of money. He said k&n air filter, aftermarket exaust, and jetkit would make zero noticable power change. This is coming from a licensed Arctic Cat mechanic and shop owner so it got me wondering. I found it hard to believe that no modifacations would result in a power change. If any 400 owners with mods has any info it would help alot.

 

Not true. Filter + exhaust + jet kit is highly likely to add power, but don't expect to turn it into a 500 eater. Exhaust is a small gain in performance and I think most people do it for the change in sound.

When I did mine, it felt snappier but that's about it. Nothing major.

 

if you are trying to modify your 400, why didnt you just buy a 500

 

You said your 400 is new,, I`ll assume `07 or `06. I`ve read alot on here about 400`s really waking up after 500 or so miles. I suggest waiting to get passed this break in period before making any modifications. When you do decide to make changes, do them one at a time. That way you`ll be able to notice if there is a power gain and if it was worth the price you paid for the mod.
As for me, the only changes I`ve made is a winch, front bumper and seat cover. My style of riding doesnt warrent a jet kit or a new muffler so keeping mine stock serves me just fine.

However, a new filter, exhaust and jet kit may add power but certainly will make it a bit more efficient. Anyone reading this who has done a jet kit, correct me if I`m wrong but arent they for fine tuning for higher altitudes ?? I dont know much about them.

My 2 cents.

 

Often wondered the same myself - by the time one gets done with mods (and still doesn't have the power of a stock 500) they have more invested than just buying a 500... I don't know, I am just a "Dummy"...

 

I have a 500 auto and talked to AC dealer regardign a clutch kit. He told me it would be noticible especially at take off, mudduing and hill climbing. Mine is an 04 with 250 miles but I am seriously thinking about the clutch kit.

Mike

 

If you do a lot of mudding and hill climbing I guess - why not. However, keep in mind that most everything is a trade off for something else. The clutch kits are by design to allow higher rpm's before engagning, then lock up quicker and firmer - all designed to keep you in a higher rpm zone with out bogging down. Where you may loose out is with articulate riding where you are climbing over rocks and stumps or any other situation where you need slow, smoothe, progressive power. These kits are going to give you alot of power all at once, like reving up a standard shift car and dumping the clutch.

So weigh the type of riding that you do most of the time and make a good choice based on that. Do the modifications on your machine that suit yor riding most of the time and don't worry about the occasional stuff.

Personally I do very little mud, only when I have too, if there is a way around I will go around, I don't do sand dunes and don't do hill climbing. I take off and ride 60-100 miles at a time over stumps, rocks, across brooks up the side of a mountain and down the other side, I run over trees and brush, I drive up dried-up book and stream beds that are full of rocks and green slime on them, if that is the only route I can take, I traverse across hills that are covered with pine needles (about like putting grease on a rock) so I set my machine up to be a trail/woods machine. So my machine is set to start to give me slow, progressive, smooth power right of from idle.

 

I will tell you something funny that happened to me. I went to push over a white birch tree (a very springy type of tree) one time. Wrong idea, I ended up falling off the back of the machine with the machine in a 70 degree wheelie leaning against that tree with the rear bumper only inches from the ground...
The funny part of it was I said to my 'better half' - "Now how in h_ll am I going to get that Cat out of the tree"... Well we both sad down on the ground and had a good laugh over that comment...

 

I went out looking for a 400 or 500 4x4 auto originally. I found a 06 LE with 40 miles on it, guy owed 5300 on it still, said he bought it for his wife and she only used it to get the mail on his paved driveway. This thing didnt even dust on it. Paid 4500 for it . His receipt said he paid 6400 for it. The price I paid and the fact that the LE was loaded sold me on it. For many reasons this quad is perfect for me, but if I could change a few things that would make any noticeable change in power I would like to. I dont want to drag race, just conquer unriden grounds and be able to extract my quad easily when Im alone. It has 120 miles on the motor now sow Im going to wait awhile before I start any mods. I was just curious after hearing the shop owner tell me not to waist my money on aftermarket parts. I was wondering what 400 owners with these mods done had to say.

 

Wait a bit for the mods. The 400's really come to life after 300-500 miles. Decide on the type of riding you will be doing most of the time and go from there.

I personally have done no mods to the engine etc. On a good day on asphault I can get 52mph one hard dirt roads I can get 50mph, (I have had it up to 70mph - so what if it was in the bed of my pickup -lol)... I do mostly trail and woods riding. I wanted my machine to handle good, to be stable and tackle a variety of turf. I avoid mud when possible, no sand dunes, not much hill climbing, but I do drive over trees and brush, over big rocks, over stumps and brush piles, dried-up brook and stream beds with slimey green stuff on the rocks, up mountains and down the other side, over pine-needle covered hill sides (like having grease on a rock)... What is important to me is slow, smooth, predictable, low end power that comes in just off idle and is progressive with no supprises....