The Yamaha YZ 125 has a 125cc liquid-cooled 2-stroke engine with a reel valve inducted. It has fuel delivery of Mikuni TMX 38 and Constant-mesh 6-Speed transmission with multiple wet clutches. This dirt bike can handle any terrain thanks to its lightweight design.
If you want to improve its performance and reliability then here are the top mods of this bike, then read the full article.
Top 5 Mods
Here are the top 5 mods that you can do to your Yamaha YZ 125 dirt bike to get better performance
- Cylinder Porting
- Suspension upgrade
- Better Handling
- Cylinder Head
As you know, YZ 125 is a two-stroke dirt bike. The YZ125 has pretty good ports from the factory, but there’s always room for improvement. You can upgrade its cylinder porting for better performance.
When it comes to 2 stroke engines, cylinder porting can make or break the power band. Only port the cylinder yourself if you know how to do it. The engine runs sour if you don’t take good care of it. I suggest you to take the services of a professional who can give you the exact power curve you want. This will increase a little boost in the torque, and it can also increase the rev response for wood riding.
Keep in mind, it’s not always better to go bigger with the ports. For overall performance, it can sometimes be better to go smaller in some places.
A bike needs to provide a smooth and bump-free ride. Although YZ 125 has invented KYB Fork, these are not adjusted according to your weight to handle all situations. So to make these suspensions reliable, you must adjust the springs according to your weight and riding. The forks can be adjusted by moving them upwards and downwards in the triple clamps and adding spacers to adjust the preload.
A stock dirt bike is usually set up for riders weighing 160-180 pounds. So if you are overweight, you can adjust the suspension according to your physique and enjoy a smooth ride on this dirt bike.
After the Suspension adjustment, there is a high chance that your dirt bike gets unbalanced, making handling difficult while riding on the trails. So to overcome this problem, you have to balance the bike.
Setting the bike’s height is the thing that makes your bike stable, so you can adjust the shock sag to balance your bike. If you still significantly face the instability issue in your bike while turning, you can lower the rear wheel.
Suppose you want your dirt bike to be adequately maintained, providing a smooth and trouble-free ride on any terrain. Then you can add JD jetting jet kit in your YZ 125’s engine. It is one of the best options to add and make your dirt bike suitable for any situation.
The JD jetting gives the perfect air and fuel mixture to the bike’s engine for satisfactory perform. After applying this kit, you will not feel any lag in the engine performance, even while climbing. It also has an advantage which is its custom needles; this means you can adjust the needles according to the elevations.
When the clutch is engaged, the engine is temporarily disconnected from the gearbox and drivetrain system responsible for driving the rear wheels. By the abusive use of the clutch, it gets slippery and overheats easily, so to prevent it from doing this, you have to upgrade the clutch.
It can be dangerous if the clutch comes out from the corner, especially when riding this bike fast; that is why an upgraded clutch is essential. Manual shifting makes your clutch discs last long.
You can add a new clutch, but if you are using your YZ 125 for long rides, it is good to use an automatic clutch. The lever feels the same as stock (or even better/softer), but the automatic clutch is more convenient. It keeps the engine running automatically by slipping the clutch.
Cylinder head work is to close the engine’s combustion chamber from the top, and it is the easiest way to gain power, throttle response, and easier jetting by increasing compression. So you can replace your stock one with an aftermarket cylinder head. This will increase the torque and give a better throttle response.
You can use VHM and Phathead (the most popular) cylinder head for your 2-stroke bike. Several types of combustion chamber inserts are available for different compression ratios from both manufacturers.
Cylinder porting, suspension upgrade, jetting, cylinder head, and clutch are the top mods you can add to your YZ 125 dirt bike to increase its performance. It’s a suggestion to avoid trying to install these upgrades by yourself; always use the services of a professional, as it is a high chance that you can damage the engine or the specific part you are upgrading.
You can upgrade its suspension, jetting, cylinder head, clutch, and cylinder porting to increase its performance and make it all terrain dirt bike that can even handle the weight of a massive rider.