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Big throttle body kit φ34 released by SP Takegawa.
There are many ways to enjoy engine tuning, but perhaps the easiest is to change the intake and exhaust systems. Replacing the muffler is a particularly popular customization, but changing the exhaust system alone will not contribute much to speed. It is important to also change the intake system and review intake and exhaust efficiency at the same time. SP Takegawa has released a large number of intake and exhaust system aftermarket parts. This time, we would like to introduce the installation procedure for a big throttle body kit for the Monkey 125. As usual, this is a digest of the video “Let’s power up your Monkey 125! SP Takegawa Big Throttle Body Kit Installation Guide!” uploaded to “Moto Champ TV,” a free video streaming service on YouTube.
This means that the diameter can be increased by 10mm from the original 24mm diameter of the throttle body.
If you have changed to a muffler with good exhaust, you will want to enlarge the intake system to achieve an intake that matches the exhaust efficiency. SP Takegawa’s big throttle body kit is a 34mm diameter specification, which is 10mm larger than the original intake, which is 24mm diameter. A larger diameter means that more air can be drawn in. By combining a big throttle body kit with a muffler with good exhaust, even a stock engine will become surprisingly lively.
When installing the big throttle body kit, the SP Takegawa fuel injectors are also replaced at the same time.
However, installing a big throttle body kit also requires changing the fuel injectors. If the amount of gasoline injected remains the same even if the amount of air intake increases, the mixture will simply become lean. Therefore, we recommend changing to the SP Takegawa G-1 fuel injectors at the same time to create the ideal mixture.
Removing the genuine air cleaner box
First, we will start by removing the factory air cleaner box. We will show you step by step the process, with lots of photos.
The air cleaner box cover can be removed by removing the two Phillips screws at the bottom and pushing it from the back towards you. There are tabs on the back, so be careful not to break them.
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Once the cover is removed, you can see the various sensors attached to the air cleaner box. First, press the center tab on the right side of the vehicle and pull it out.
There is also a sensor on the left side of the vehicle, so remove that. There are also hoses attached, so remove those as well.
Remove the sensor and hose and then remove the two bolts securing it to the frame, then you can pull out the box.
Removing the original throttle body
Once the air cleaner box is removed, it’s time to remove the original throttle body. There are many steps, so we’ll explain the process step by step with photos.
Remove the three sensors on the left side of the throttle body. They are all different sizes and numbers, so you shouldn’t make a mistake when installing them.
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Remove the throttle pulley cover and remove the throttle wire from the pulley. Loosen the nut on the cable that is inserted into the holder to loosen the wire.
Remove the injector at the front, then lift the throttle body up to remove it.
The throttle body can be removed by removing the two bolts connecting it to the intake manifold.
Throttle body sensors transplanted
The removed throttle body also has sensors attached. These will be transplanted and reused in the SP Takegawa throttle body, so remove the sensors and other parts from the original throttle body. The sensors use O-rings, which will also be reused, so be careful not to lose them.
Remove the cable holder from the throttle body and remove the throttle opening sensor and idle solenoid.
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The opening sensor uses a Torx screw, so you will need a Torx tool to remove and install it, so make sure you have one on hand.
The opening sensor and idle solenoid removed from the original parts are transplanted into the big throttle body.
The throttle opening sensor is installed by aligning the recess on the inside with the minus-shaped protrusion on the body. In this state, the fixing position will not be aligned, so after installing it, turn it to position it.
In addition to the sensor, we also transplanted the idle air screw from the factory throttle body. Stop tightening it halfway before fully tightening it, restart the engine, and then adjust the idle speed.
Installing the big throttle body
Once the sensor and idle air screw have been transplanted, it’s time to finally install the big throttle body onto the engine. The important points to note here are summarized below, and will be explained with the accompanying photos. The other various sensors and hoses will be installed by reversing the removal procedure, so no photos are included.
Attach the rubber gasket that comes with the big throttle body kit to the intake manifold, then combine it with the dedicated intake manifold.
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Pull out the original blow-by hose and replace it with the long hose included in the kit.
Temporarily fasten the throttle body to adjust the length of the blow-by hose. After installing the power filter, set the original insulator in the direction shown in the photo above, and then install the big throttle body to the engine side.
Align the temporarily fastened big throttle body with the long hose, cut off the excess, then secure the big throttle body with the specified torque and connect the hose. After this, simply connect the various sensors and hoses by reversing the removal procedure.
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