If you own a Coleman CT200U or CT200U-EX mini bike you know how much fun they are to ride. However, as you spend more time in the seat of one of these machines, you quickly realize that they are not very fast. But don’t worry, that can be fixed.
To make your Coleman CT200U or CT200U-EX faster you can install a torque converter, remove or bypass the governor, and add performance kit parts. Each of these modifications can be done alone or you can do them all. So let’s look at what these easy upgrades entail and how they can boost your top speed.
Install a torque converter
Adding a torque converter is a great way to improve your mini bike’s performance. Not only will it give the bike better low end power for take offs and hill climbs, but it will also increase your top speed. Many claim that their mini bikes went 10-12 miles per hour faster after adding a torque converter.
Replacing your centrifugal clutch with a torque converter is a little more complicated than just taking out a few bolts and putting them back, but anyone with a little mechanical know how can do it. It also means you are going to have to break out your wallet. Most torque converter kits cost somewhere in the neighborhood of $200. This may sound like a lot, but when you feel the difference in performance, you will know it was money well spent.
If you decide to buy a torque converter kit, make sure you measure your crankshaft before ordering. Coleman manufactured the CT200U and CT200U-EX with two different crankshaft sizes. The older models had a 3/4 inch crankshaft and newer models have a 5/8 inch crankshaft. To be sure which crankshaft size is on your mini bike, simply take a tape measure or ruler and measure across the diameter of the crankshaft.
Remove the governor
Coleman engines have a governor system that is comprised of a series of levers and springs that connect to a governor gear with flyweights inside the crankcase. This system keeps the engine from operating above 3,600 rpms. Bypassing or removing the governor allows the bike to reach rpms of 5,000+. Higher rpms means higher speeds.
The zip tie method or bypassing the governor is probably the easiest and definitely the least expense modification. Many people start here because it’s basically free and only takes a few minutes. All you need to do is tighten a zip tie around the coils of the governor spring located under the gas tank. This will prevent the spring from stretching and engaging the governor system.
Removing the governor system is inexpensive, but not simple. This process involves opening up the crankcase to remove the governor gear. When you’re done, you are left with a hole in the top of the crankcase that you will need to make sure you plug.
Once you get your engine back together you will need to either purchase a top throttle plate or engineer a way to secure the throttle cable to the carburetor so the twist throttle will work properly. Anytime you open up your crankcase, the risks of something going wrong increases drastically, so make sure you know what you’re doing before you start.
Removing or bypassing the governor can be dangerous. These motors were not engineered to consistently run over 3,600 rpms. There is a chance that prolonged use at higher rpms can result in a bent push rod or valve stem.
The worst case scenario is the cast iron flywheel shatters under the increased stress. This is not only bad for the engine, but also for the safety of the rider. When a flywheel goes, it sends pieces of shrapnel tearing through the crankcase and anything else in it’s path. I don’t know about you, but I don’t want to be sitting on top of the engine when that happens.
If you want to remove the governor without the risk, think about upgrading the flywheel, rod and valve springs. Later in this post we will talk about different performance kits that involve these upgrades. You can also check out our post What does a Governor do on a Mini Bike? for more detailed information.
Add a performance kit
One of the great things about the popularity of Coleman mini bikes is finding after market parts is really easy. There are numerous companies out there that offer performance kits to increase your mini bike’s horse power. We are going to focus on the ones offered by OMBWarehouse.com and GoPowerSports.com. These two sites are major players when it comes to the after market go kart and mini bike parts.
Performance kits are offered in different stages. For example, at OMBWarehouse.com a stage 2 kit has all the same parts as a stage 1 kit plus a couple more. So you want to decide up front how big you want to go. You can still start with a stage 1 kit and add more performance parts later. It just doesn’t make much sense to spend money on a stage 2 kit that includes a lot of the same parts you got in the stage 1 kit.
The kits offered by GoPowerSports.com build upon each other. So a stage 2 kit is added on top of a stage 1 kit. You can buy a stage 1 kit now and then add a stage 2 kit later. Let’s see what each has to offer.
OMBWarehouse.com stage 1 performance kit
OMBWarehouse.com’s Stage 1 Performance Kit is specifically for the CT200U model and was designed to give you 1-1 1/2 more horsepower. This kit is easy to install and easy on the bank account with a price around $75. Let’s take a look at what’s included in this kit:
- Angled Air Filter
- Air Filter Adapter
- Choke Hold Adapter
- Heavy Rubber Gasket
- .037 Jet
- 1″ Exhaust Header w/Screw-on Muffler
- Exhaust Header Gasket
This kit is a great, however, it does not fit on the CT200U-EX or BT200X frames. Also some Coleman mini bikes come with a stock EPA carburetor that does not have a removable main jet. You may want to check your mini bike carburetor before purchasing a Stage 1 kit because the Stage 2 kit might be the better choice.
OMBWarehouse.com stage 2 performance kit
OMBWarehouse.com Stage 2 Performance Kit may be a better option for many. It was made specifically for the stock 196cc Hisun engine used on the Coleman CT200U and CT200U-EX. Unfortunately, it will not work for the CT200U-EX “Camo” bike. Here’s what it includes:
- Angled Air Filter
- Air Filter Adapter
- Choke Hold Bracket
- Heavy Rubber Gasket
- Non-EPA stock style carburetor
- .037 Main Jet
- 1″ Exhaust Header w/Screw-on Muffler
- Exhaust Header Gasket
- 18lb Valve Springs
The inclusion of the non-EPA carburetor guarantees the .037 main jet can be used. The install is a little more complicated than the stage 1 kit because of the valve spring install, but still pretty easy. There are plenty of YouTube videos on the valve spring install to refer to. Also, the gauze type air filters like the one in this kit must be oiled with a filter oil before use. K&N filter oil is available at most local auto parts stores.
OMBWarehouse.com stage 3 performance kit
If you are thinking about removing your governor, the Stage 3 Performance Kit is a great option for running your bike at higher rpms. Like the stage 2 kit, it won’t work for the CT200U-EX “Camo” bike. The kit Includes:
- Angled Air Filter
- Air Filter Adapter
- Choke Hold Bracket
- Heavy Rubber Gasket
- Non-EPA stock style carburetor
- 1″ Exhaust Header w/Screw-on Muffler
- Exhaust Header Gasket
- DynoCams MOD2 Camshaft
- PVL Flywheel
- ARC Billet Rod
- 18lb Valve Springs
The install of this kit is complicated and involves opening up the crankcase. If you haven’t ever done this before, again you will want to do your homework and watch some videos first. There is a lot that can go wrong when you open up an engine, but luckily these engines are pretty simple and straight forward.
OMBWarehouse.com stage 4 performance kit
The last and most powerful OMBWarehouse.com kit we are going to discuss is the Stage 4 Performance Kit. OMBWarehouse.com claims it can double your power to over 13 horsepower! Sadly if you have the BT200X, RB200, or CT200U-EX “camo” bike it won’t work for your bike. For those of you that have a Coleman bike that this fits, here’s what’s included:
- Angled Air Filter
- Air Filter Adapter
- Choke Hold Bracket
- Heavy Rubber Gasket
- Non-EPA stock style carburetor
- 1″ Exhaust Header w/Screw-on Muffler
- Exhaust Header Gasket
- CM Grind “Super X” Camshaft
- PVL Flywheel
- ARC Billet Rod
- Hi Compression 14cc Head
- 18lb Valve Springs
This race inspired kit will make your Coleman mini bike a whole new animal. Now let’s take a look at what GoPowerSports.com has to offer.
GoPowerSports.com stage 1 performance kit
This Stage 1 Performance Kit allows the engine to breathe better by moving air in and out more efficiently. This gives it more power, roughly an additional 2-3 horsepower. The install is very easy and takes about 20-30 minutes. The kit is pretty affordable and will only set you back about $120. The kit includes:
- 1 Air Filter Adapter
- 1 K&N Style Hight Flow Air Filter
- 1 Upgraded Main Jet – .038
- Carb Gasket Kit 196/212
- Exhaust Gasket
- 1 Coleman Header Pipe
- 20″ Safety Header Sleeve
- 212cc/196cc Stock Clone Carburetor
- Header Support
- Vent Filter Kit
When you add a header pipe to a mini bike, you end up with a searing hot pipe sticking out of the side of your mini bike. This makes the chances of someone accidentally getting burned pretty likely. GoPowerSports started including a 20″ Safety Header Sleeve with all of their header pipes to address this issue. It is a great addition to this kit and hopefully more companies will consider adding this.
GoPowerSports.com stage 2 performance carburetor
If the GoPowerSports Stage 1 Performance kit still isn’t quite enough power, you can add the Stage 2 196cc/212cc Honda Clone Style Carburetor. In order to run this carburetor, you must have at least the Stage 1 Performance Kit installed. It only takes a few minutes to install and comes already jetted for maximum power. At the time of this post, the carburetor cost around $50.
Other performance parts
There are a few other parts that are not part of GoPowerSports performance kits, but still worth considering. The first is the 1″ Exhaust Silencer. This muffler is designed to give the engine a little more torque while making the engine a little quieter. Keep in mind “silencer” is a strong word. Your mini bike will not be silent, or even quiet, but it won’t be quite as loud with this muffler.
Replacing the flywheel, connecting rod and valve springs go hand-in-hand with removing the governor. These upgrades prevent damage to the engine and the potentially dangerous situation at higher rpms discussed earlier in this post.
A billet flywheel, is lighter and creates less drag. This means more power and quicker acceleration. The billet connecting rod is strong enough to handle the increased stress at higher rpms so you don’t have to worry about it getting bent. Unfortunately, GoPowerSports.com does not offer internal engine parts for the stock Hisun 196cc engine. So you will have to look at OMBWarehouse.com or another supplier.
The CT200U and CT200U-EX have 10lb stock valve springs. Upgrading the valve springs to heavy duty 18lb valve springs will provide better control of the valve at higher rpms. These springs prevent “valve float,” a condition created when the motor spins faster than the valves can fully open and close. This condition causes a loss of power at high rpms and high risk of damaging the valves, springs, or in some cases even the piston.
Installing a new flywheel, connecting rod and heavy duty valve springs is a much more involved process than just bolting on a new carburetor and air filter. Essentially you have to take the entire engine apart and then put it back together exactly right. There is a lot of opportunity to make a mistake, so make sure you do your research, take your time, and follow the instructions to the letter.
Conclusion
There are a lot of ways to upgrade your Coleman CT200U or CT200U-EX mini bike to satisfy your need for speed. OMBWarehouse.com and GoPowerSports.com are only two suppliers that offer great options to transform your mini bike into a speed machine for a relatively low investment. Many of these modifications will not only increase your top speed, but also reinforce your engine. Happy riding.