Looking for the best KDX 200 mods to make it faster and more comfortable? Whether you just want the cheapest upgrades for a little better performance or the best possible parts, you’ve found the right article!
In this article, I’ll show you what the top mods are that actually make a difference, why each part or upgrade works, and how to get the most gains by combining certain mods.
Before you start modifying your KDX
There are two things you need to know. First, just adding more power won’t necessarily make you ride faster. Two, adding just one or two random aftermarket parts may not give you much more performance, but I’ll explain why.
When you add more power, but the suspension is not properly set up for your weight and riding style, it’s only going to be harder to control that extra power.
Also, adding a pipe and reed’s has more potential for power, but if they are tuned correctly, your bike can actually run worse… keep reading to learn why.
Air box mod
The stock air box on a Kawasaki KDX 200 is very good at keeping out mud and dirt, but that’s also a problem if you want the most power. There’s so little room for dirt to get in that not enough air gets in, and you need air going through the carb to properly mix with the fuel to make power.
The air box has a lid on top with a small intake opening. By simply removing this lid, you give the air box a much bigger opening for more air to enter.
When more air can get in, you have potential for more torque and horsepower. The only downfall is that it can suck a little more dirt in – that’s why keeping the air filter clean is essential if you want your 2 stroke engine to last a long time!
Jetting – the key to any good running dirt bike carb
Jetting is one of the most important factors on your Kawasaki 2 stroke dirt bike. If you want your KDX200 to start easily, run well, be reliable, and have the most power, you need to learn how to properly jet the carburetor.
Don’t worry – it’s not as hard as you might think, even if you’ve never done it before. Even if you make a mistake, you can go back to your original settings that you should write down when you start.
The stock jetting for the ’95+ model years is:
- 48 pilot jet
- 160 main jet
They usually run pretty rich, so going down to a 42 or 45 pilot jet and a 155 main jet is a good starting point, especially if you’re fouling plugs and smoking a lot after the engine is fully warmed up.
Gearing up or down
One of the easiest and cheapest ways to make your KDX 200 accelerate quicker or add top speed is by changing gearing. Stock gearing is 13/47 teeth for the front and rear sprockets.
Going up to a 49 or 50T (Amazon) in the rear can give you some better acceleration in the lower gears. Or going up to a 14T (Amazon) on the countershaft will give you a higher max speed so you can cruise at a lower RPM in 6th gear.
While the stock suspension isn’t terrible on the KDX 200, it’s nothing to write home about. It’s nice and soft for casual to moderate trail riding, but that may be too soft if you’re riding faster or you’re a heavier rider (200+ lbs).
So, there are some simple, as well as more complicated things you can do to make the forks and shock work better. Going stiffer is just one element.
There are two relatively easy and affordable things you can do, especially if you’re mechanically inclined and do it yourself. Heavy duty fork springs will increase the front end preload and prevent bottoming better.
This means the forks will hold up better while riding, especially if the stock springs are too soft – they’re made for riders 140-160 lbs.
They’ll also resist bottoming better, which is a safety factor because you can lose control if you’re constantly bottoming the suspension out – you might hear or feel a clank/bang.
You can also use heavier weight fork oil. This will increase the damping because the thicker oil slows down the compression and rebound of the forks. Adjusting the oil height will also affect the bottoming resistance.
There are two important things you need to be correct with the rear shock, as well as the forks. First, they need to have the proper springs rates – install stiffer (Amazon) or softer springs if the stock/current ones are not right for your weight and riding style.
The next important thing is to adjust the ride height. Adjusting the ride height affects the suspension balance, so once you get it balanced front to rear, your bike will handle better and the suspension will work better so that it’s more comfortable and it will give you better traction.
Ride height adjustment is done be changing the sagk the rear shock preload. Refer to your OEM service manual for specific numbers, but it’s generally in the 95-105mm of sag when you’re sitting on the bike.
Aftermarket exhaust pipe – Which one?
The stock pipe is one of the biggest parts holding back the KDX200 from making more power. It has multiple layers, which is great for preventing big dents and lowering the exhaust decibel rating, but there’s room for power improvement.
An aftermarket pipe, such as the FMF Gnarly pipe, will add some overall power with proper jetting. If you don’t do anything with the jet circuits, you may not see any gains – it can actually run worse, depending on your bike, climate and currenting jetting specs.
The FMF desert pipe, if you can find one available, is made for top-end horsepower. You might lose some off-idle torque, but that won’t matter if you don’t ride at low RPMs often.
Silencer – Is it worth it?
According to my research, the stock silencer is not as much of a choking point as the stock expansion chamber part of the pipe. That means upgrading to an aftermarket silencer (Amazon) won’t gain as much performance. That is, unless you see “looks” and a little bit of weight savings as performance.
Reeds that make a difference
A reed upgrade is a simple and effective way to gain power on most 2 stroke dirt bikes. But some reeds don’t always add much, if any power, to certain bikes and engines.
Here’s what I got back after doing some digging on upgrading the reeds in your KDX200:
- Budget – Boyesen Power Reeds (Amazon)
- Best – Mototassanari Delta Force 3 Reed block with carbon fiber reeds (Amazon)
So what does this mean? You can spend more or less and get a similar effect on your overall power. Upgrading the reeds alone might not do a whole lot, but a combination of upgrades that are built for the same goal (low-end or top-end power), along with proper jetting will give you some fairly significant power gains.
RB carb mod
Want more mid to top-end horsepower? If you don’t mind sending your carburetor out to get worked on, an RB Designs carb mod is a nice upgrade.
With the RB carb mod you get:
- Carb bored to 36mm – better mid to top end HP
- Custom carb divider – for better low-end throttle response
- Slide modification – better off idle response
- Updated needle
- Circuit mods
- Pre custom jetted for your bike and climate – some fine tuning may be necessary with the air screw
Want more power? Just make the intake and exhaust ports bigger and polish them, right? Wrong!
You may hear this and that on forums online, but porting is more of a science and knowing how a specific engine works. For example, the ports on your cylinder may not need to be bigger, but rather smaller or just shaped differently to get the type of power increase that you specifically want.
This is why you want a professional 2 stroke engine builder and tuner to do the porting. Finding one that knows how to tune a KDX would be best because they might have a proven system for the best performance.
One of the reasons the KDX 200 has such a mild power curve for a 2 stroke is because of the conservative engine tuning. This includes a cylinder head with loose clearance.
The result is a lower compression ratio, so increasing the compression will give it a small boost in power. It can also increase the efficiency of the engine because it burns the air-fuel mixture more completely if done right.
Sending your cylinder head to a professional tuner to get the some re-shaped and/or turned down will do this. A thinner base gasket will also increase the compression, as well as change the cylinder port timing slightly.
Caution before modding the head
All this should be done with enough clearance in mind – you don’t want the piston getting too close to the cylinder head when it reaches top-dead-center of its stroke. Checking the squish band clearance is necessary, and that’s why this last mod is best left to a professional that’s familiar with tuning the KDX 2 stroke engine.
Top KDX 200 mods
So, to sum it up, these are the best band for your buck mods for your KDX 200:
- Air box mod
- Carb tuning
- Shock rebuild
- Carb mod
- Better rider
The best mod to become a better & safer rider
Getting your suspension setup for your riding weight and style is super important, and then adding power where you like it, but there’s something that will help you even more. A better rider is the best mod because so many people fail to master the basic techniques, and I want to help you prevent that so you stay safe and build your confidence faster – click here to download my free basic technique guide.