Tuning and Modifications: How to change your reed valves


1.  Let me first start with the fact that I am NOT a mechanic.  I have been working on motorcycles and scooters for a long time and know a little about what I am doing.  I simply take pictures for other people to use as a guide line to help them modify their own motors.  Any modifications you perform are done completely at your own risk and liability.

2.  Tampering with your motor in any way may void your warranty.  Make sure this is a sacrifice you are willing to make before you begin working on your own vehicle.

3.  Before you begin, make sure you have a nice clean area to work in.  A small amount of dirt can be a big problem when working on the innards of your motor.  Keep your hands, motor, and any other parts you are handling very clean.

4.  This example was performed on a 2003 Aprilia Mojito.  All 2-stroke motors have reed valves.  This includes DiTech model scooters also.  The reeds are always located in the top of the crank case where the air intake goes into the motor.

5.  ALL bolts and socket head cap screws are in metric! Don't try to work on your vehicle if you don't have metric tools, you will just end up messing up the heads.


First start by removing the four screws that attach the intake from the carb to the motor. Your reed cage is located under this. 2 of the screws are safety screws which have a post sticking up out of the middle. You will need to get a 5mm allen head wrench with a hole in the center of it to remove these. I simply drilled a hole into the end of one of my allen bits. I have heard of people using vise grips to remove these also, although I wouldn't recommend doing this.
With the intake removed, the reed cage will now be exposed. Simply pull the reed cage out from the motor.
Now remove the screws that hold the reeds onto the reed cage.
You will notice the carbon fiber reeds have two holes for each screw. Lay the carbon fiber reed onto the old reed and determine which of the two you need to use compared to the old.

Also there is a notched corner at the top of each reed. I don't know why this is here, but I was sure to line them up. If you switch to the other side, all you have to do is turn the reed over and it will work on both sides. I installed my reeds with the Malossi facing toward the intake. I don't think it makes any difference as to which way you do this.
Once you have the new reeds attached, they should look like this. Now replace your reed cage back onto the motor and re-attach the intake.

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