XR100 Mods – Top 5 Things To Make It Faster

Do you have an XR100 sitting in your garage that is getting a little outdated, but don’t have the money to buy another bike? If you a little extra cash, though, there are some cheap ways to make your little ol’ Honda faster and more fun to ride.


Before you go any faster, you may want to consider bracing up your frame with a frame cradle. They can be a little costly, but if you are going to be jumping or doing any kind of racing, it is a must. An xr100 relies on the stress of the engine and its mounts to hold it together, making it flex and eventually break. A frame cradle adds much needed rigidity to the frame, taking the stress off the engine.


Next you’ll want to upgrade the suspension. Yes, you’re probably asking why we’re not doing any “go-faster” mods. Trust me, we’ll get there, but your bike must be able to handle the abuse before it can dish more out. Every adult that’s ridden a stock xr100 knows the suspension is less-than-satisfying. In two words; it blows. Literally, it bottoms out just riding over bumps if you weigh anything over 140lbs. Heavy duty fork springs are a cheap upgrade, and can be swapped out at home with some basic shop tools. A heavy duty rear shock is around the same price. So for less than 200 bucks you can have an xr100 that rides much better, and is ready for those “go-fast” mods.

Stock XR100
Stock XR100


Like many other things on this dirt bike, the intake is highly restricted. Honda XR’s run rich from the factory, and this is one of the main reasons why. Swapping out the entire intake system for a pod-filter would be the least-restrictive and provide the most power gain, but I wouldn’t recommend it unless you’re doing supermoto with the bike. It’s out in the open, so it’s more susceptible to sucking in water and dirt. A free mod you can do is drill several 1/2″ or 1″ holes around the around airbox. This will allow more air to get in and to the engine. You can also pull off the air-filter and remove the back-fire screen on it. It restricts air-flow, and an xr100 has very little chance of starting a fire by back-firing.

Another common intake mod that xr100 owners do is replace the carburetor with one from an ATC200X. That’s right, an old Honda 3-wheeler. An XR200 carb will fit as well, but the 200X is the most because it’s a slightly bigger bore than the XR100 carb (24mm vs. 22mm) and bolts directly onto the xr100. If the throttle cable is too long, just buy one from a CR80/CR85. The 200X carb will likely need to be taken apart for a cleaning, so you might as well re-jet while you’re there (or get a rough estimate on where to start).


An aftermarket exhaust is relatively cheap and easy way to hop up your XR100. Not only does it open it up for more power, but it sounds a lot better than the choked up stock exhaust. You may not need to re-jet the carburetor with just an exhaust, but if you do the previous intake mods, you will need to re-jet to make it run smooth and get the most power out of the modifications.


If  you want to spend a little more dough, you can do a lot of different things to the engine. A big bore kit is fairly cheap and easy to do, and a hotter camshaft will give it some ‘giddy-up’. You can get the cylinder head ported, shaved, and/or blueprinted if you’re looking to keep stock displacement. For those that want to go all out, there’s “Super Head” kits that come with a complete top-end, including a larger cylinder head with bigger ports and valves to increase air-flow. For this kind of money you could buy another dirt bike, but, if you’re racing it in a highly competitive class and have a lot of extra cash, I’m definitely not going to stop you.

Socalxr XR100 Conversion
XR100 conversion built by Socalxr

Before you do any of the last three mods, though, you should know that in order to get the most out of the bike, modifications should be done to all of them. In other words, you’ll gain a lot more horsepower if you open up the intake AND get an aftermarket exhaust, as opposed to just doing one or the other.

In the end, it’s going to take either a lot of money or time (or both) to make an XR100 competitive on the motocross track. But that’s not what an XR100 is intended for; it’s a fun, backyard, play-bike. If you have the mechanical abilities and motivation, check out my budget xr100/rm80 conversion build for some ideas on how to build the ultimate pit bike for adults…

-Tom Stark

Can I Shift Without Using The Clutch On My Dirt Bike?

This is a common question that many riders ask, and it often causes a lot of bickering. What is the best way? Well, that depends on a couple things. Really, it mainly comes down to what kind of riding you do, and rider preference. One way can be faster than another, and one can possibly cause more harm than others… Or can it?

With the Clutch

There are two ways you can shift through the gears while using the clutch. The first one, if you are conscience about the longevity of the transmission in your bike, is probably the easiest on it. When you go to shift, pull in the clutch and let off the throttle simultaneously, then shift and release the clutch. Not only are you taking load off of the transmission by letting off the throttle, but you are also reducing the load by dis-engaging the clutch. This is the most common way of shifting that is taught to new riders. If it is what you are comfortable with, by all means, continue to do so.

Learning how to shift a dirt bike.
Learning how to shift a dirt bike.

The second way to shift with the clutch is usually the fastest, and a lot of professionals do it this way. Instead of letting of the throttle when shifting, you hold it open. Sounds bad? You want to time it right so that it’s still in the power-band when shifting. When you go to shift it up a gear, hold the throttle wide open and give the clutch a quick pull while shifting it up to the next gear at the same time. It’ll sound like it’s over-revving, but it’s only for a split second if you’re fast enough. This is why four-strokes have a rev-limiter; so it stops revving higher before something breaks. Two-strokes don’t have a rev-limiter because they stop revving before anything would happen. Not only is this way of shifting fast, it also keeps the RPM in the meat of the power-band when you get to the next gear.

Without The Clutch

This next one is still easy on the transmission, and the way I usually do it when riding around the farm/trails for fun. It’s the same as the first one, except you are not using the clutch. So it’s just: let off the throttle, shift up a gear, then get back on the throttle to accelerate. For some reason, many people think that dirt bike transmissions are like cars transmissions and say you need to use the clutch to shift, otherwise it will destroy the gears. This is not true, as dirt bikes have a constant-mesh transmission, allowing you to shift up or down through the gears without the need for the clutch. However, you can only shift up or down one gear at a time, unlike a car where you can select any gear at virtually any time.

The last way to shift through the gears is probably the hardest on your transmission. Although it is made to take the abuse, many people would not recommend using this technique. Professionals do it because it’s faster, but they are using race-bikes that are expected to have a much shorter life-span. When going through the gears, keep the throttle wide open, and when the power starts to run out near the end of the RPM range, firmly shift it up to the next gear. This takes a little more practice, as you do not want to shift it while accelerating under a heavy load. Once you get to the end of the power-band, but before redline, is when you want to shift it. The bike will lose a little power at really high RPM, which will reduce enough load off the transmission to allow you to shift it.

How To Shift Gears On a Dirt Bike
How To Shift Gears On a Dirt Bike

In the end, I believe that it’s personal preference and what kind of riding you are doing that should determine how you shift gears on your dirt bike. I am just telling you that it’s not going to blow up your transmission if you shift without using the clutch. I would know, because I’ve been doing it for years with no problems.

-Tom Stark

This is a good illustration on what your transmission is doing when you shift.


How Much Is My Dirt Bike Worth? Top 5 Factors

“What is my bike worth?” is a common question people ask when they are looking to sell their dirt bike. While there are numerous factors that determine how much you can or will get for your bike, there’s never a set price for any certain make and model bike. To give you a better idea, I’ll show you the top factors that influence the value of your dirt bike.

What color is your bike?

As weird as this may sound, some bikes sell more quickly and for more money than others. It can depend on your location, but generally, red and blue bikes are easier to sell. Why? Because people like the colors red and blue. That’s not to say you aren’t going to sell your lemon, lime, or orange-colored bike quickly. This has just been my speculation based on the used bike market for the past 8-10 years, and probably will be for a while.

Three 125 2-Strokes
Which Flavor Do You Have?

How Many Strokes?

Two-strokes have been getting more popular around the country, and even the globe in the past couple years. They are cheap to maintain, easy to work on, and a blast to ride. This means that their value has noticeably increased, especially if the bike is in good shape. Four-strokes are still conquering the motocross world, but a 250F or 450cc MX bike that’s more than 5 years old is more than likely beat up. If you’re comparing the two, a 2-stroke is going to hold it’s value longer because an engine rebuild is a lot less costly.

Different Strokes For Different Folks
Different Strokes For Different Folks

How Many Aftermarket Parts?

Sure, you can add $3000 worth of aftermarket parts to your $1000 dirt bike, but that doesn’t make it worth $4k. In fact, some people prefer stock or close to stock bikes. Why? A bike with a lot of aftermarket parts has been messed with more than a stock one. This increases the chance of something not being put back on the bike correctly and failing in the near future. The people that want aftermarket parts on a bike are looking for something that is set-up for their kind of riding, which is not very common. If you want to get the most return on your used dirt bike, put the stock parts back on it when you put it on the market, then sell the aftermarket parts separately.

Lots of Bling
Lots of Bling

Check The Market

While KBB and NADA may give you an estimate of how much your bike is worth, it’s just a guesstimate. To give you a good idea, check your local market for how much your model dirt bike is worth. Try to get an idea of how much one in good shape is priced at, and how much a beat up one is. Once again, these are still estimates, but are more accurate because they’re real, and they’re local. Why are they still estimates? Because 99% of the time the seller does not get the asking price. The used dirt bike market is all about haggling. For example, if you want $2100 for your motocross bike, try listing it for $2400. That way the buyer will think he’s getting a deal if he works you down to what you wanted. However, there’s still no guarantee you’re going to get what you want for it.

Was It Maintained?

This is usually the number one factor in selling a used dirt bike. Most people that come to look at a bike are going to know right away if it has been maintained at all. First of all, is the bike clean? Does it start up right away and not make any unusual sounds? Have the oil and filter(s) been changed regularly? What kind of shape are the chain and sprockets in? Has the engine been taken rebuilt? If so, who did the work? How many hours does it have? These are all common questions that you should ask yourself before you try and sell your dirt bike.

This Bike Looks To Be Mint!
This Bike Looks Mint!

Still Not Selling?

Has your bike been on the market for a while and still not sold? Perhaps you are asking too much. If you aren’t getting any calls or emails from your ad, consider lowering the price 100-200 bucks. Also, how descriptive is your ad? Does it have any pictures of the bike? If it doesn’t already, try adding some info about the bike that people calling would ask. Another important factor in selling a dirt bike is the time of year. Are you trying to sell it in the winter/off-season? If so, it’s going to be harder to sell it, and you won’t get nearly as much for it. The best time to sell a bike is in the spring when riding season is right around the corner, or is just starting. When kids, and even adults, see others riding, they see how fun it looks and instantly want a bike for themselves.

If you need more help on selling a bike, check out my other article for tips on How To Sell A Dirt Bike.

-Tom Stark