I have a 05 400ex. It has a K&M air filter, its jetted, and an aftermarket exhaust pipe. What are some other things I could add to make it faster and have more power?

Im looking to spend around $100 or less. Any suggestions?

 

More power? You've already got most of the cheap stuff done. You could change the sprockets. Won't really change the power, but will change how it's delivered. Different carb or going in to the motor sounds like the next step, and it's not going to be under 100 bucks.

 

What will changing the sprockets do?

Also what would you do to the motor? and how much will it cost

 

Depending on what changes you make to the sprockets will give you different results. Say you went to a bigger front and smaller rear sprocket. You will have quicker acceleration, but you will also lose some top speed.

You could get a 440 or 460 kit and get some more power, but you're looking closer to 1000 than 100 dollars.

What type of riding are you going to be doing? If it's trails, I'd go with a sprocket change as you're not hitting top speed most times anyway. Plus, it's a whole lot cheaper and easier to do.

 

I really dont want to sink a ton of money into this because I plan on getting a Raptor 660 or 700 within 2-3 years

I do a lot of riding on flat ground around my farm, but we also go to the sand dunes 3-5 times a year.

When I ride around my house I use all 5 gears. When I go to the dunes I usually climb in 2nd or 3rd, and when were just riding on flat parts I usually run in 4th because it seems like I slow down when I shift into 5th

 

If it were me, I'd just keep on riding it then. It's not going to make it worth much more money if you put a lot of parts in it anyway. It's dependable and it's fun. Enjoy the ride.

 

If you have opened up the intake and exhaust, have you noticed you are hitting the rev limit easier? if so, find a modded cdi with a +1000 rpm rev limiter. It will allow you to stay in each gear a little longer, getting better acceleration and power out of the engine. One thing I have noticed about Honda quads is the low rev limit they have from stock, this is one thing that keeps them "reliable" by forcing you to shift out sooner and preventing any over rev from wearing on the engine. problem is, you open up the breathing, it revs better and quicker, and you hit the limit so fast, it actually hurts performance. I used the cdi on my son's 300 ex and then his 440 ex, both benefitted from the extended revs, and years later, are still running strong, never had a problem with engine wear or damage.

 

I seem to hit the limit fairly fast. A lot faster then when I ride my stock 400ex.
Where should I look to buy a rev limiter? Ebay? or is there a specific one you would recommend?

 

I picked up both mine on Ebay, one was a White Bros. cdi, the other i can't remember the brand. there are usually plenty of good used ones and new ones there, watch out for "modified" cdis that someone dug into and 'removed' the factory limit, those can fail easier and not having a safety limit in can let you damage the motor. 1000 extra rpms is usually plenty for most non-race situations.

 

Can you link to to a couple you would recommend?