I just picked up my 650 Brute on Friday and have a few questions.
1) I have had many atv's (YFZ 450, ex 400 , KFX400) is there an airbox mod? or just take the lid off? I dont plan on riding in water.
2) Will a K&N or other filter help? Assuming that I take the lid off?
3) Is there a pipe mod? I saw that some people are cutting/welding.. thats too much effort for me.
4) What about the performance plug in chips? Dyna? I dont wnat to cut my wires as I plan to buy the 4 year ext warranty.
5) Also, how fast do you guys go in "low"? I realize that you want to be in low as much as possible to preserve the belt right?
Thanks!!!

 

First, Order you a shop manual and visit tech tips on website atv.dnsalias.com.

Second. Best bang for buck for ME has been the Dyna CDI & Orange/Blue primary clutch spring which are plug and play; just in case quads needs to go back to dealer for waranty.

Low gear speeds top out near 40+MPH unless you have Dyna CDI & top-end clutch mod. My 02 with mods hits 50-53 in low

Look at my signature. Recommend any or all mods. With all my mods Quad is a wheelie Monster & not for the faint at heart, especially in LO gear.

Jetting/needle height/mixture setting & clutch tuning are the keys to top performance on your Quad.. Quad also respond well to headporting, Higher compression pistons, and Larger Cams.

Happy Trails, You just purchased one of the best Quads on the market. [img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]

 

How are the primary clutch springs plug and play?
In a nutshell, how do you repleace them? How much are the aftermarket ones?

 

DonEX400
Plug and play simply means take old one out & put new one in. Again visit above aformentioned & recommended website & read all Tech and performance tips untill your heart is content; will answer 99.9% of your questions. [img]i/expressions/face-icon-small-happy.gif[/img]

 

Yes, the k&n makes a difference, There are allot of pipe systems out there, from slip on to full systems. My personal favorite is the Procircut, there are some pics on my page that you can see the pipe. The K&N without the lid will work fine if you want to take the time and effoert to re-jet for that application. You will see a difference in the K and N by it's self but likely won't run with out the lid untill you put more fuel to it. I have had the Dyna boxs in all of mine without a problem but there is a new one comming out that lookes pretty cool from VDI. I like Plug and play, never did any of the moduals ????.


CONGATS ON THE NEW QUAD, GREAT CHOICE

 

upgrade the tires to

 

1. Airbox mods - it will not pull itself with the lid removed, you'll have to rejet. You can buy or make a larger snorkel. By my calculations, the new snorkel is about 3 times larger (cross-sectional area) than stock.

2. I run foam filters (UNI in this case). I don't trust K&N's.

3. There is a pipe mod, but I have not done it. I had a HMF Utility on and loved it, but I have removed it for now (had to send it back to HMF for a bad rivet job and am too lazy to put it back on).

4. I have a VDI module and it is a tremendous difference. I asked both of my dealers (I bought from one and the other does the service) and they both said it will not affect the warranty. I will buying the VDI CDI when it's ready and selling the module. Moose has a module that is plug-and-play (no cutting required).

5. I've never checked speed in low. I never ride in low except for obvious high load situations.

Buy a service manual - it's such a great resource.

 

Thanx for all of the replies!!!
Any idea what the jetting should be if I take off the lid?
Actually, I took the seat off for the 1st time last night and dont even see an airbox!!
I guess it is under one of the side covers?
I am at 800' elevation central IL

 

You should get a service manual then. The airbox is under the cover that would appear to be a gas tank. There are two black quarter-turn screw things. Turn them using your key (or a coin), pull them out and the cover should lift up from the back first. Be sure to get all the tabs back in the front as you put it in (there are several and it's sometimes difficult to get them lined up.

 

The only one I have the no lid K&N setup on is the FST 800 big bore. Ray Fundy gave me the jet sizes to use, we did and dyno tested it and used the o2 sensor on the dyno. His recomendation was spot on. It added 4 HP on my big bore and air fuel is perfect. He is a performace GOD when it comes to the Kawi twin. I would drop him an e-mail, he is a heck of a nice guy. I am sure he can tell you exactly what jets to use.



Here is a link to his site



I am not sure if this link will work but his address is http://www.fundypowersports.com/index.html