“Budget” and dirt bike riding usually don’t go hand-in-hand, but there are many ways to make it more affordable. This tip is something so simple that will make your clutch last longer. You may already do it some of the time without even knowing it, but you may be able to improve upon it. It is a problem that I see quite often (I see a lot of guys/gals on street bikes doing it as well).
By now you’re probably thinking, just tell me what it is! Okay, I don’t like reading much either so I won’t waste time. When you come to a stop, put the bike in neutral and let out the clutch if you are going to idle for a period of time. That’s right, all you have to do is remember to keep the transmission in neutral with the clutch engaged (lever released/out).
If you’re still reading this, you may be wondering, “But why?” That is a valid question, so let me explain. When you pull in the clutch, even when the lever is all the way to the handlebar, the clutch fibers and friction plates are still spinning against each other ever so slightly. Even at idle, the friction of the plates rubbing will cause them to heat up. This will result in them warping over a shorter time period if you regularly do this on rides.
Dirt Bike Clutch
So, how do I know when and where to change this habit? Simple; if you come to a stop and know you’re going to sit there for more than a couple seconds, shift it in to neutral. You may forget to do this more often that not at first, but if you make a habit of it, it will become just that.
I hope this quick tip helps. Free free to post a comment, question, or a suggestion.
Having starting or running problems with your TTR125? There’s a good chance that the stock carburetor is your problem. Instead of spending hours trying to fiddle with it, a carb swap can save you a lot of headaches and make your bike start easier and run much cleaner. Here’s a step-by-step video tutorial on how to convert to the Mikuni VM24 carburetor. If you’re unsure about this conversion or have questions on why you should do it, read all the details on swapping out the stock carb HERE.
Motocross Hideout includes anything dirt bike related, even if it is ridden on asphalt. So, just what is a Supermotard? Yep, a dirt bike with sport-bike style wheels and tires for riding on the street. If you’ve ever ridden a dirt bike on the street, you’ll know how exhilarating it can be when you whack the throttle and the front wheel comes off the ground. Motards are the ultimate hooligan bike, and can get you into a lot of trouble if you don’t follow the rules. However, if you want to legally ride on the street or go to track-days on a road course with your dirt bike, here’s some things you will need to replace or install.
Wheels
If you want to convert your dirt bike to a supermoto, you’re going to need ‘Sumo’ wheels and street tires. 17 inch wheels, front and rear, are the most common for supermoto, and are much better for street riding than the stock 21/19 that are stock on most full-size dirt bikes. They lower the bike, they handle better, and they’re wider so you can lay more rubber down. 3.5″ width is typical for front supermoto wheels, and 4-5″ are the most common for the rear, with several in between. You can go wider or narrower, but you may run into tire width issues, as well as the wheel being too wide and rubbing on the chain and/or swing-arm.
Tire size selection is important in order to make your motard ride right. If you have a rear tire that’s too wide, it can actually hinder the performance. For example, if you have a 4.25″ rear wheel with a 160/17″ tire, the wheel will be pinching the bead of the tire because it is wider, thus creating a more extreme profile with a smaller radius, and ultimately less road surface. However, if you put a 150/17″ tire on the same wheel, it will have more contact surface on the road and perform better than the wider tire. This is research that you should do for your specific year and model bike to determine what combination is best.
Supermoto Wheels
There is also the more extreme route for those that have the machining ability and want to possibly save a few bucks. Street bike wheels from certain bikes can be retrofitted to work with your dirt bike. However, there is usually machining involved to make clearance to fit on the swing-arm and/or forks. Bearings are fairly easy to swap out, but you’ll either have to find wheels with the same size bearings as your dirt bike to fit the axle, otherwise you have to buy some bearings with the correct size inside and outside diameters. Another problem that may come up if you choose to do this conversion is mounting the caliper. This depends on what size rotor you’re going to use, or if you want to put the stock caliper on the wheels you’re using. I can’t recommend a certain set-up for everyone, as there are so many different bikes and combination of wheels. Unfortunately, that is where YOU will have to read-up on as well. I don’t recommend going this route unless you are mechanically inclined and have the machining capabilities/resources. Lastly, cast wheels are not as strong as spoked supermoto wheels, and they will not be able to withstand the abuse of jumping and off-road riding; just something to keep in mind as well.
Lights
Lights are required if you’re going to ride on the street. Every state is different, but the usual requirements are a headlight (hi/low beam), tail-light/brake-light, mirror, turn signals (hand signals are OK in some states), and reflectors. Headlights are fairly easy to install if you carefully read and follow the instructions (I know, that can be hard for the guys…). However, if you are using a motocross bike, you will either need an alternate or bigger power supply. An upgraded or rewound stator is probably the easiest way to go because that alone will power the lights. You’ll need to get a regulator to go with it so you don’t burn the lights out.
Lighting Kit
Unfortunately there’s not an aftermarket stator for every dirt bike, or at least one that’s reliable. Another easy way to get usable lights for your street legal conversion is with battery power. You can buy an aftermarket lighting system for most bikes, such as the DRC EZ electric wire kit. It is powered by a battery pack of 8 AA batteries that are easy to swap out. They will last several hours, depending on how many lights you have and what kind of wattage they pull.
Another option would be using rechargeable Lipo batteries, such as ones used in RC planes and cars. They should be 12 volt (4 cell) to match the lighting system. This route requires a little more initial cost, but being able to recharge the battery makes it easy, especially since you don’t have to worry about carrying around a bunch of small AA batteries.
Brakes
In order to go faster, you must be able to stop faster. If you’re converting your dirt bike to ride on the street or asphalt, you will want to upgrade the front brake. The rear brake isn’t as important because it’s not doing as much braking, so it’s adequate for most riders unless you’re highly competitive in supermoto racing. The brake-system is fairly simple in regards to modifications. You have the master cylinder, brake line, caliper, and rotor. The quickest way to get more braking power is by replacing the rotor with a bigger one because it produces more leverage. 320mm is a popular rotor size for motards to have, but there’s some things you’ll have to consider.
Most bikes can use the stock caliper with a larger rotor, but the stock location will not work. This is why you must buy a relocation bracket in addition to the rotor. Be sure you buy the correct bracket, though, as the size/brand of rotor and caliper may vary. Calipers with four or six pistons are a common upgrade, as this will also produce more stopping power.
A steel or aluminum braided brake line is a fairly inexpensive accessory to your braking system, and they perform better than the stock rubber hose. They are built to withstand more pressure, and give you a more consistent and less “mushy” feel compared to stock.
Upgrading the master cylinder can get expensive, but if you are racing and want the most power with less effort, a better Master will complete the package. There’s quite a few options out there to choose from, and generally, you get what you pay for. On the flip side, many riders on a budget find an MC from a different dirt bike, street bike, or even a quad that is better than what they already have. Remember to do some research as to what works with your specific bike if you decide to upgrade.
Sumo Front Brakes
Accessories
Last, but not least, are the ‘accessories’ that you must add to your motard to make it “street legal” and pass inspection if needed. Every state is a little bit different, so I will just hit the basics on what’s required. Almost, if not every, state will require a working horn. This doesn’t have to be anything fancy. In fact, a lot of riders buy a cheap bike horn from wal-mart. Turn signals may or may not be required. Hand signals are legal in some states.
Most states need a headlight with a hi-low beam headlight, as well as a working tail/brake-light that works with the rear brake. Reflectors are a good idea, whether they’re required or not. It will make you a little easier to see, and if you get pulled over, the deputy may take you more seriously if you add little safety things like this. You will likely need a mirror to be legal, so a simple handlebar mounted or bar-end mirror will work.
A road-legal exhaust is a good idea if your bike is being inspected. Most dirt bikes have “For off-road use only” stamped on the stock exhaust, which isn’t going to fly if a cop scrutinizes your motard. Also, bikes that carry passengers must have an appropriate seat set-up and passenger pegs. I know that supermoto’s are solo-bikes 99.9% of the time, but it’s just something else to keep in mind.
Now it’s time to start building your bike! All of these parts add up quickly, which is why properly set-up supermotards (especially when plated) are so expensive to buy used. You probably won’t get your money back when you go to sell it, but it can be worth the money to know that you built it with all of the parts that you want. If you do some shopping around and have the whole winter to piece your bike together, you can find some good deals on used or even new parts. Besides, if you buy a complete supermoto kit for your dirt bike, you can always go back to the stock set-up if you want to ride in the dirt again.
I know that was a lot to take in, so you should bookmark this page/website and come back to it throughout your build. If you just want to see all the parts involved in making a supermoto, here’s a simple list (how far you want to go down it is your decision):
Supermoto wheels and street tires
Street gearing/sprockets (depends on what kind of riding you’re doing)
Headlight
Tail/brake-light
Upgraded stator or battery system for lights
Larger front brake rotor and relocation bracket
Better front brake caliper and master cylinder
Turn signals
Mirror
Horn
Hi/low beam headlight switch
Reflectors
Street legal exhaust
Passenger seat/pegs
If you have any questions, either post a comment below or click the Contact tab above and shoot me an email. Have fun building your own Supermotard, and ride safe!
Wheel bearings inevitably fail over time, and that time is much less if you often ride your dirt bike through water. Water and mud will eventually seep inside if you leave it wet, causing the bearings to rust and end up seizing. An easy way to tell if your dirt bike wheel bearings are shot is by moving the wheels side to side. If the wheel moves at all then the bearings need to be replaced. Some tools you will need to replace wheel bearings include:
Wrenches to remove wheel
Screwdriver
Punch
Bearing retainer tool/pliers
Hammer
Bearing installer/socket
Before taking any parts off your bike, give it a bath so that it’s easier to work on. Keeping your dirt bike clean makes working on it much easier, keeps you cleaner, and you will be able to tell much sooner if there’s a leak or other problem with your bike. Once your bike is spotless, set it on a stand and remove the wheel that you are replacing the wheel bearings on. Now put the wheel on a wheel stand, a wooden box, or even saw horses to make it easier to work on without damaging the rotor or sprocket.
Wheel Bearing Retainer Removing Tool
Remove the seals by prying them off with a screwdriver so you can get at the bearings. One side will have a retainer clip or nut, such as the one on Honda motocross bikes, which you’ll want to buy the special tool for. They are pretty cheap for a specialty tool, but make sure you get the right size because they changed over the years. You can try tapping it out with a small punch if you’re careful, but I wanted to re-use the retainer, and for under 20 bucks, it’ll pay for itself even if I only use it a couple times. Tools like this will save you time and the hassle, especially if you need it again sometime down the road.
Once you remove the retainer, flip the wheel over to remove that bearing (If you bought a fancy bearing remover tool, just use that, otherwise for the rest of us that are cheap, continue reading these instructions). Before you go to punch it out from the other side, you’ll have to take the punch and push the wheel spacer that is in between the bearings over so you can hit the bearing with the punch. Now just hammer on the punch to knock the bearing out of the wheel. Punch the bearing in a circular rotation so that the bearing comes out straight and doesn’t gouge the bore of the wheel. The wheel spacer will come out once that first wheel bearing is out, so set that aside until you need to re-install it.
Now you can flip it back over and knock out the other bearing(s). Just make sure you punch them out as straight as possible. Before you install the new bearings, I recommend putting them in the freezer. Metal slightly shrinks at cooler temps, so this will help make the installation a little easier. Clean the area and surfaces of the wheel on both sides where the bearings go in and set your wheel back on the stand/wood blocks.
Some people say to heat up the hub where the bearings go to make it easier to install them, although others will say that it weakens the metal. I haven’t seen any issues caused by heating it, but it’s up to you whether you want to use heat or not. I didn’t use any on my recent rear wheel from a CR125, but it took a little more force to press the bearings in.
Take the wheel bearing and set it on the journal where you will press it in. You can start out with a piece of wood or flat piece of metal and hammer it in until its flush. Make sure you know that it is going down straight, otherwise it can damage the surface. Next, you’ll have to use a round piece of metal or a socket that is almost the same size as the bearing. You want to be hitting on the outer race (outside circumference) of the bearing and NOT the inner race. If you press or hammer on the inner race you will destroy the bearing. Keep hitting the bearing down while making sure it’s straight. You will hear or feel when it bottoms out in the bore, and that’s when you stop. Now you can put the clip or retainer ring/nut back on, along with the seal.
Removing The Seal and Bearing
Flip the wheel over to do the other side, but before you put the other bearing(s) in, REMEMBER TO INSTALL THE WHEEL SPACER. This is just the sleeve that you took out that goes in between the bearings, and it can be easy to forget until after you press all of the bearings in, resulting in hair-pulling frustration. Now you just repeat installation on this side, whether you have one or two bearings left. If you’re doing it all by hand, just be patient and get them in straight. It may take some time, but the bearings will go in (assuming you bought the correct part).
Now you can install the other seal to complete the wheel bearing installation. When you go to put the wheel spacers on, put some waterproof grease on them to help protect the seals and bearings. If they are worn with grooves then they should be replaced, otherwise water will find it’s way to the bearings much easier.
That’s it, just put your wheel back on the same way you removed it and remember to properly torque the bolts. If you have any questions, don’t hesitate to post a comment below…
Not too often will you see me devote an entire article on a “Make My Dirt Bike Go Faster!” article, let alone on a bike that is meant for beginners. However, there are numerous advantages to this modification on all Yamaha TTR125 models. If you’ve bought a used TTR125 or have owned one for a while, chances are that you’ve had some problems with the stock carburetor, whether it be a bad choke, sticking float/needle, or jetting problems that make it hard to start or not run right.
You can try different pilot and main jets in there, and even fine to the needle position, but it just never seems to run quite right, and it get worse with time. Some parts of it are just poorly designed and they don’t work right after so many years. Fortunately for those of us that like to fix things, these problems can be cured with a better carburetor. Even better yet, a new one can be found for under 100 bucks!
So, why is the Mikuni VM24 round slide carb better than the stock Mikuni on Yamaha’s TTR 125 four stroke dirt bike? First of all, it’s not as finicky and is easier to jet. Once you get the jetting dialed in, you shouldn’t have to mess with anything other than possibly an air screw adjustment in the cooler riding season. Want more power? Because this carb will give you that, even if your TTR is stock. It will make a bigger difference if you have intake, exhaust, and even engine mods (big bore/cam), but with a stock set-up you’ll get better throttle response everywhere and it will rev out much further, making it feel like a different bike.
Junk Stock Carb
If you’re tired of messing with the dumb bar-mount choke on the TTR, you can throw that out as well with this new carb conversion. The choke is mounted right on the new carb itself. In fact, a lot of owners of this swap say that it usually doesn’t even need the choke to start, even when the engine is cold.
What Do I Need for This Swap?
Mikuni VM24/ss carburetor
Screwdriver
Pliers (needle nose)
Drill with 5/16″ drill bit
New jets (Depending on where you get the carb)
New 6mm Fuel Line (1′ is plenty)
File or new clamp?
How Do I Install It?
Technically, I wouldn’t call this a ‘bolt-on’ swap because there are a couple modifications you have to make. However, this is one of the easiest conversion projects you will find when swapping dirt bike parts. Total time should be 1-2 hours if you have everything ready, and even less if you’ve done it before. First thing to do is take off the throttle cap from your new VM24 carb, as well as the one from your stock TTR125 carb and remove the cable/adjustment screw so all you have left are the bare caps. You will be using the stock TTR throttle cable, which will require the metal elbow off of the stock carb cap. It’s held in place with a locking clip, so just pull that out with some pliers.
Now you will need to drill a larger hole on the new VM24 carb cap so the TTR cable/elbow can fit through it. Some people say they used a 1/4 drill, but the TTR elbow fitting measured .285″, which is about 9/32″. That drill might work, otherwise you can go up to a 5/16″ drill (.312″) to make it fit. If you are wondering about the threads, yes they will be gone after you drill through it, but you don’t need the adjustment screw from that cap for it anymore. Now you can put the elbow assembly on the new cap and hook the TTR cable up to the slide.
Some owners of this conversion mentioned that the new carburetor is shorter in length, requiring you to stretch the inlet-side boot to make it reach. I did not have this problem when I swapped it onto my 2000 TTR125L. The clamp on the inlet fits without modification, but the engine side of the carb boot didn’t clamp down far enough on mine. You can either get another clamp, or just file down the spacer in the stock clamp so you can tighten it down more.
After you have the carb bolted in, the only thing left is the gas line. You will more than likely need a longer one to reach the new carb. You can either wrap it around the back of the frame to keep it out of the way, otherwise you can just route it underneath the frame, which is a shorter distance.
If you haven’t already, you can completely remove the stock TTR125 choke and cable because it isn’t needed anymore. Also, for those of you that have the newer model TTR125’s with the two-cable throttle set-up, just use one of those cables with the new VM24 carb and remove or tie up the other one, as it doesn’t use two cables.
New, Better Carb
Just turn the gas on now and fire it up! Adjust the idle screw knob when it’s warmed up and it purrs like a mountain lion.
Where Do I Find The VM24 Carburetor?
Fortunately, these carburetors are very easy to find and buy. Not only does Mikuni make a lot of them, but you can also find them off of used dirt bikes for cheap. Sudco and eBay are common places to buy them new. You can also get a VM24 off of a 65cc 2-stroke motocross bike, such as a KX65. They require different jetting, but once they are dialed in, it will run just as well. They pop up on eBay all the time, and can be had for as little as 30 bucks or less. If you’re lucky, you might be able to get away with buying a new jet or two and giving it a good cleaning. If it has a lot of hours, though, it may require a rebuild kit. This isn’t so bad, but it will end up costing almost as much as a new carb. On a side note, I recommend not buying a Chinese knock-off carburetor. They make inferior parts and will more than likely cause problems down the road; just the opposite of what we are trying to do with this swap.
What Jets Should I Use?
Depending on what mods have been done to your bike and where you live, your results may slightly vary. If you’re buying a new Mikuni VM24 from Sudco or from an eBay seller that sells new ones, they come jetted fairly close, although you may need to swap out a jet.
Like I mentioned above, if you’re using a VM24 carb from a 65cc 2-stroke then it will require different jets to run properly. The 65’s need much richer jetting compared to the small-bore four-strokes, so you’ll need to change the main jet for sure, and possibly a pilot, depending on what comes with it. Don’t worry, jets are only a few bucks, and they share the same jets as most other Mikuni VM and TM carbs.
Below are average starting points for the two different VM24 carbs you can put on your TTR125. These are based off of an elevation of about 1000 feet, and a temperature of 70 degrees Fahrenheit. The engine is stock, but it has an aftermarket exhaust.
New VM-24 From Sudco:
Main Jet: 105
Pilot Jet: 17.5
Needle: 1st or 2nd clip position from top
Used VM24 From KX65:
Main Jet: 155
Pilot Jet: 27.5
Needle: 1st/top clip position
Air screw: 1-1.5 turns out
The needle is about the only thing that may be harder to tune. It runs a little rich, especially with a bone stock TTR, even at the leanest position. I haven’t found any leaner needles you can buy for it, but after riding the bike for a little bit and allowing it to fully warm up I didn’t even notice a hesitation. Other than that, this bike runs great now from bottom to top with more over-rev due to the larger bore size.
Was that too much reading to remember? I’ll give you a quick low-down on what this swap entails…
Remove stock TTR carb and throttle cable/elbow
Remove VM24 throttle cap and drill hole up to 5/16″
Install the stock elbow onto the VM24 cap that you just drilled
Adjust your needle clip while it’s out, then hook up the throttle cable and scew on the cap
Install new main and pilot jets if needed
Remove the old choke cable and one of the throttle cables if you have a newer model TTR
Fit the VM24 on (making necessary boot/clamp adjustments if needed)
Route new fuel line onto the carb.
Turn the gas on and fire it up!
If you have any questions or comments, or think like something is missing, feel free to to email me or post a comment on the article below. Good luck, and ride safe!
