A forum for owners of Yamaha TTR250 trail and enduro bikes!

These specs are based on the lowest TTR250 specs and some models may have a rating than specified below.

If your model specs are different to below refer to those specs for maximum Headlight/tail-light capacity.

I would not recommend running more than two Tail-light bulbs: 12V 5W/21W (or the equivalent) from the CDi as burnt wires or burnt out CDi may be the result. You can however run four addition tail-light bulbs by using two bulbs on each wire fitted to the CDi ''blank'' fitted, provided there are two blanks available to fit the two wires needed at the CDi unit.

I would not reccomend running more than one Headlight bulb:12V 35W/21 W off the additional CDi wire.

If you want to use a headlight bulb over 12V 35W/21 W, I would recommend buying a WR light switch & running a 10-15-amp wire from your CDi to the light switch feed wire. If you are wanting to do this, remember to upgrade the high/low wires (yellow & green) to 10-15-amp & run these wires from the high/low switch to the headlight, SEE HERE for more info & also read the ''Upgrading'' section.

There is a reason YAMAHA have specs and a good rule is to always adhere to it!

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For your reference the specs are:

Fuse:15A

Headlight bulb:12V 35W/21 W

Tail-light bulb: 12V 5W/21W

Note: If your model specs are different to below refer to those specs for maximum headlight/tail-light wattage.

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Section One:

Fitting additional lights & accessories

This section is for anyone wanting to fit items below 12V 35W/21. If you want to fit an item with a higher capacity than this, scroll down to ''Upgrading Electrical Components'' after reading this section.

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1.You can fit additional electrical components to each ''blank'' provided that you are not exceeding the maximum wattage. 

2. If you want to fit a headlamp bulb up to 100W you will have to run it through your ''WR'' light switch and to headlight. This is so you can use high/low beam.

3. I would advise to use a fuse for high wattage or delicate items but most accessories should come with them.

First thing is to find the blank (plug) in the Cdi connection under seat. You will have to take your seat off to find it..

This diagram should help find the blank (plug).

NOTE: This is looking from the outside of Cdi connection with clip at the top...

Also you should be able to see the two ''blanks'' (plugs) in this pic but looking at your Cdi connection should be enough...

Now that you found it (hopefully) unplug the Cdi connection and take out the blank N1. shown in diagram above. Either one will do but I'd use the one at the top right blank N1. first.

Note: Some models may be using blank N1., but not common.

You can remove the ''blank N1.'' by using the right size needle (blunt side) and pushing it through from the inside of the Cdi connection.

Next find a tiny spade connector with the rubber grommet on it. You can find these in good electrical stores or just use an old Cdi (black box) and take the wire out.

• Note: If it is like the TTR one you will have stick a needle or similar down the side of the connection to depress the retaining clip, then push the connector through.

Now that you have a ''tiny'' spade connector it should easily push straight in, making sure the rubber grommet is all the way in. No force should be needed!

Next..

Find a good place on the frame to mount an earth wire and once it is mounted fit to lights/accessories.Now make sure you have all wires insulated with shrink wrap (or taped) and check they will not rub through when seat is put back on and are not sticking out.

First... ''YES'' the power will run through the additional wire when the ignition is on. You could fit whatever you like provided it does not go over the specified headlight bulb capacity Headlight bulb:12V 35W/21 W on the ''one Blank plug''. Gps's and mobiles will be fine to run.

NOTE: If fitting Gps's and mobiles I would definately advise that you use that you use a spark plug with a resistor built in.

Note: If using the TTR250 standard NGK CR9E it has a resistor in it.

If you want to fit an accessory or headlamp bulb over 12V 35W/21W (E.g.. 100W) you will need to upgrade the standard wire to 10-15-Amp from your CDi to the accessory fitted. You can do this without Upgrading electrical components but I wouldn't recommend fitting any other ''additional'' electrical accessories or light(s) without upgrading electrical components or a flat battery may be the result.

If you want fit a headlamp bulb up to 100W, you will have to run 10-15-Amp wires from the CDi through a WR light switch and to headlight. This is so you don't burn out your wires and can use high/low beam.

If you are confident enough that you are not going to exceed the maximum voltage, you can go ahead & fit the additional light or accessory, if not see below.

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So you can understand better.

An open voltage circuit is what your battery should be 12.8V or more at 20 degrees celcius

A closed voltage cuircut is what comes out from your cdi eg. 11.81V at 20 degrees celcius

• The AC magneto's job is to generate the power.

• The ressistor/rectifier's job is to lower the power, convert it from AC to DC and keep the voltage constant so it doesn't blow up the CDi (eg. voltage too high).

• The CDi has many jobs, but in this case it just helps lower the voltage further like a relay does.

• The power gets generated by the AC magneto, which then goes through the ressistor/rectifier.

• The ressistor/rectifier then converts it from AC to DC voltage and feeds the power to the CDi.

• The 15A fuse's job is just a ''back up'' measure to make sure the charging power does not go over 15 A

• The cdi then lowers the voltage further by going through an ''additional'' diode (see pic above)You now have a reliable source of power coming out of the cdi ''Blank plug'' .

• The ressistor's ''job'' (that comes standard with NGK CR9E spark plug) is to make sure there is interference with the electrical items fitted.

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Checking the voltage is not exceeding the maximum limit

Step 1. Battery test

1.

A few of you will know how to do this but it is as easy as putting a multimeter on the battery (positive~positive) (negative~negative).

 The voltage must be 12.8V or more at 20 degrees Celsius.

 If your battery is 12.8V or more at 20 degrees Celsius proceed to the next step, if not charge or replace battery, then move onto Step 2.

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Step 2. Closed circuit test

1.

Check the voltage at the ''additional'' wire from the CDi that you fitted from the ''blank'' with a multimeter while running all lights (high beam) and accessories with the blinker on. The voltage should be the same as a closed voltage cuircut eg.11.81V

If the voltage is the same as a closed voltage cuircut then then you can move onto Step 3.

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Step 3. Checking charging system

1.

Check your bike to see if you have a tachcometer installed

2.

If you found it move on to N5.

3.

If you did'nt find it, I'm not suprized as it's not fitted as standard lol, go to N4.

4.

Attach an inductive tachometer ref # YU-8036-A attach to the IGNITION coil

5.

Now attach a multimeter to the battery terminal (positive~positive) (negative~negative)

6.

Start the engine and accelerate to about 3,000 r/min

•The voltage should be 13.0~15.0V at 3,000 r/min

If the voltage is 13.0~15.0V at 3,000 r/min all is okay.

If not, move on to the next section of this thread.. Upgrading electrical components.

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Section Three:

Upgrading electrical components

This section is for anyone wanting to fit an item that is over 12V 35W/21 W.

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First of all, I would reccommend to buy an aftermarket, high crank Amp battery SEE HERE.

If wanting to fit HEAPS of lights & accessories, in addition to the high crank amp battery, I would reccommend an aftermarket AC magneto to have more ''power'' charge your battery. Something like THIS would be okay, but there would be better brands?

I would advise that you use that you use a 20-AMP 3-PHASE regulator / rectifier, rather than the Standard OEM 10-AMP rectifier if wanting to fit HEAPS of additional lights or accessories or high wattage items over 100W.

If you want to fit an accessory or headlamp bulb over 12V 35W/21W (E.g.. 100W) you will need to upgrade the standard wire to 10-15-Amp from your CDi to the accessory fitted. You can do this without Upgrading electrical components but I wouldn't reccomend fitting any other ''additional'' electrical accessories or light without upgrading electrical components or a flat battery may be the result.

If you want fit a headlamp bulb (up to 100W) you will have to run it through a WR light switch and to the headlight. This is so you don't burn out your wires and can use high/low beam.

If you want to fit an accessory or headlamp bulb over 12V 35W/21 W E.g.. 100W you will need to upgrade the standard wire from your CDi to the accessory fitted. I would recommend using either 10A/15A wire ran from the Cdi to the WR light switch.

You will have to buy a WR head light switch if you don't want to solder the standard one (if fitting a headlight) click here

I would advise to have a fuse for high wattage or delicate items but most accessories should come with them.

•Use a fuse the same amps as the specified additional light or accessory for high wattage or delicate items (see item for info).

Also you may want to get an aftermarket CDi unit something like THIS.

Once you have upgraded the electrical components, go through the steps above again keeping in mind that your charging power should nearly double (if fitting upgraded Ac magneto ) and battery power may be slightly higher.

You should now have all the info you need to do the job properly. Hope this helps someone and is easy to understand?

If you have any questions let me know.