For Many of the CRF electric owners or anyone who has used the X model taillight, it has probably gone out on you. Well I have an easy fix to save the cost of a new one just by replacing the resistor's in the lights.
By my judgement, Honda used two 100 ohm resistors to create the necessary resistance which is about 20 ohms too little by calculations. They would burn out and make the light useless. I have an easy, inexpensive fix for about 5 dollars, and if your LED's are still good it's only about 1 dollar. There are two ways to do this, one is two go with the stock system with 2 100ohm resistors, or you can just use 1 220ohm resistor. If you do the stock system you will need four 100 ohm 1/8 watt resistors. If you do the other choice you need two 220 ohm resistors.
What You Will Need:
All of these parts you can get at RadioShack which is the only place I know of to get stuff like this
1) 4 White LED's 3.3V 25mA (If LED's still work you won't need them
2) Option A) 4 100ohm 1/8watt resistors Option 2 220ohm 1/4watt resistors
5)Rosin Core Solder
6)Philips Screw Driver
1) Here are the resistors and LED's you can buy from radioshack. Choose which way you want to go with on the resistor's and you'll buy just those. Each pack of resistor's is only 99 cents and the LED's are 2 dollars for a pack of 2.
2) Set your Light out on your work area. You will want to remove the terminals from the clip and slide the protective tubing down or completely off of the wires. Take a utility knife and not going anymore than about 1/8" down seperate the black pastic from the clear red lens. It's not going to pop off just by cutting it because there is a lip that goes into the housing.
3) Hopefully you can do this step without breaking the plastic. I had no problems and hopefully you won't either. Take a couple pair of pliers (preferably crescent wrenches) and position them about how I have them. Pry one pair of pliers in a scissors action and hopefully you can separate the two pieces.
4) Now the pieces are separated. You can see the lip I was talking about. Hopefully you were able to make it to this step with no breaking.
5) Now remove the two screws that hold the board onto the housing.
6) As You can see the two resistor's are burnt to a crisp. There's also melted plastic pegs that they use to help hold the board down even more. You will need to break the board away from the housing.
7) Take a screwdriver and pry the board up to break the board away from the housing but don't break anything. Using your soldering iron to melt the plastic and then pry it off might be a safer way.
8) Now pull the board away and pull the wires thru the grommet to get yourself some more room to work with.
9) Here's the back of the board. If you look closely you can see how the routing goes. It uses two series, using two LED's in a series. The positive volts goes in thru the diode (the black device in the very middle of the board) thru one LED to the next LED than thru the resistor's and to the ground. If anyone wants a good drawing of the routing just ask and I'll get one.
10) Now take your soldering iron and start removing the resistor's. Heat up the solder on one side and use needle nose pliers to work it free.
11) Make sure you pay attention to how the LED's are sitting in the board. You want to install the new one's in the same direction.
12) Here's everything out on one side. I recommend doing one side so you don't mess up how the LED's are sitting in the board.
13) I'm using the single 220 ohm resistor so my replacement will be different. If you do the double 100 ohm resistor's just install them just how they were originally
14) Get the solder hot enough and mess with a bit to get the holes to open back up. This will be much easier than trying to heat up the solder and push the resistor and LED through while keeping the solder warm.
15) Here's the one new LED and the 220ohm resistor installed. Since I'm using the larger resistor you will need to leave enough wire so you can twist it enough to be just as wide as the board. If it sticks out further than the board then it will hit the lens when you reassemble it.
16) Here's two new LED's Installed on one side and the resistor.
17) I hooked up the wire's to a power source and TADA!!!! It has lights!!!
18) Finish up the other side and now you should have all four lights working
19) Pull the wire's back through the grommet and screw the board back into the housing. You can try to melt the plastic pins back to the board if possible but probably not necessary. If you did a nice clean job it should look just like it's factory.
20) Like I said make sure if the resistor isn't wider than the board so it will clear the lens.
21) Super glue the lens back on. The lens has a slight curve to it so it has only one way to go back on so it's hard to get it back together wrong. Use rubber bands to hold it together or some sort of clamps that won't break it. Once your done it should look good as new.