Headlight Booster

Want more JUICE out of your stock headlight, and do not want to modify your existing wiring. Click to learn more.

HID charging conversion

Are you tired of Battery depletion everytime you uses your newly installed High Intensity Discharge Headlight, Click for solutions.

Fixing OIL drain plug thread

Are you looking for fixing that oil drain plug that went bad and unable to thread that bolt due to loose thread, Here is an easy solution for, CLICK for detais.

Led Light Solution

Wanting to conserve battery power of your motorcycle? Why not change all of your indicator BULBS, such as signal light, tail light and brake light to LED BULBS. Click for more info.


CDI is the heart of your ignition, wanting more power than STOCK but do not want to buy such RACING CDI? You need to know how it work first to understand where to START improving the ignition. Click for more.

Horn Interrupter

Want to have a horn sounds like a machine gun that produces successive sound with only one press of the HORN switch, add spice to that annoying stock horn, CLICK for details.

Reusable OIL filter mod

Paper element OIL filter tends to suffer from clogging, so why not try this filter mod I am using with my small motorcycle for more OIL flow.

Related Posts with Thumbnails

Last Updated: December 05, 2014

CRM250 MD24 CDI no spark problem

CRM250 MD24 is a 2-stroke enduro motorcycle commonly found in UK is very rare to be found in ASIA-Pacific. There are too many model of this actually and the one being the MD24 93" will be discussed. Apparently this post is the conclusion of a dear friend to whom who wrote the problem to me via electronic mail " how good the internet can bring up two people opposite of the globe to communicate and resolve some problem as if we are neighbors"...

The problem was the CDI which is costly refuses to give a  spark. All external component that directs to the ignition controller are all good and thus only the cdi was the suspect.The motorcycle was on a restoration process, and only the ignition was the problem. I had asked his permission to post all the photos here for others who has the same problem that may help you just in case.

Of course, in order for you to do so is stripped all of the epoxy resin that covers the whole black box to expose the board which is very tricky and extra care and more patience is needed. All components must be intact to the board or else it will be much harder to determine what component had failed. Servicing a defective Ignition Controller is difficult and have to isolate each and one block from one another.

Through e-mail, he sent me all the photos needed as shown.

Fig. 1
Figure 1 shows the capacitor with 1.5uf /400 volts

Fig. 2 
Figure 2 shows The MCU and Pulse shaping IC

Fig. 3
Figure 3 is PIN-OUT label of the CDI

Fig. 4
Figure 4 shows Smd components at the solder side of the cdi

Fig. 5
Figure 5  Component Side View of this cdi

Fig. 6
Figure 6  Here, he label the troubleshooting process with voltages reading.

Fig. 7
Figure 7 is the Wiring color code of the cdi

By the way, the CDI of CRM250 MD24 is an AC-CDI type, it has an external high voltage exciter coil that charges the capacitor as the engine is turn. This means that the higher the engine rpm, the higher the voltage can be measured at the charging capacitor.

Moving on finding the culprit of the no spark symptoms of this cdi. Test was done trying to find why it refuses to spark at the tip of the spark plug. Figure 6 shows the voltage reading from turning the engine indicates that there is a voltage at the anode pin of the thyristor. This means that the high voltage of the generator is getting inside, indicating a healthy High voltage generator. One pin of the charging capacitor is connected to that cathode pin of the switching thyristor (SCR), hence there will be voltage, but there will be no vltage at the other pin if your reference is ground, since the charge can only be dumped to the ignition coils primary winding, which act as the load when the SCR is triggered by the MCU. If all is good, the charge will then be dumped causing a momentary magnetic field to that winding and transferred it to the secondary winding in a x10 ratio which is enough to create spark at the tip of the spark plug.

And that is where the problem exist. It does not create any spark. Hence, with the existence of voltage across the capacitor.(by the way to see the voltage is being kept by the capacitor before the dump, put the voltage meter probe across the two pins on the charging capacitor. Voltage will remain there up until the SCR is triggered.)

So before the capacitor, the circuit is generally good. but then the output towards the ignition coil output is not. Generally, If you look at all CDI schematic posted all over the internet, there is still a major component after the pin of the charging capacitor..(did u notice it)

Fig 8
Here is an example, looking at Fig. 8, the RED BOX outline comprises the SCR, the charging capacitor, and a DAMPING DIODE, all cdi must have that diode to protect the SCR and other circuits from getting the HV back after the dump. It is actually connected in parallel to the ignition coil.

That DIODE in regards to the CRM250 MD24 photo,was traced and looking at Fig. 5. designated as D16..

And guess what, It is actually shorted. If that is already shorted then the path of the charging capacitor is nearly directs to ground and no charge will be directed to the ignition coil..

In other words, when the damping diode is already shorted, the charge will no longer flow to the ignition coil, and the system is stopped. Seems odd..that is how it works.

Many will think how the damping diode actually get blown. SIMPLE

if the ignition coil is removed from the circuit and tried to turn the engine without it. The diode will then get the ACTUAL charged of the capacitor and dumps it to ground. It is like shorting the capacitor so that it will discharged the content via the SCR. Eitherway both the SCR and the damping diode will be force to short out. and one of them will get blown, and unfortunately, D16 gets the short condition first seizing the entire circuit from functioning.

So as to state if it is good to disconnect the ignition coil to the output of the cdi when you try to turn the engine..

the answer: NO so always make sure the ignition coil is connected to the cdi. Avoid cranking the engine without any ignition coil connected, Remember, It is easier to fix IGNITION COIL related problems that CDI one, since the later is an external part of the cdi. Internal part of the ignition controller is not exposed and CDI replacement will be costly.

All credit of the photos goes to Mr. David Cooper of UK. Thank you very much, Cheers mate!

Last Updated: December 01, 2014

Motorcycle Front Brake Failure (front brake master)

Have ever been cleaning your entire brake system especially the front brake? Did u ever suspect that it needs an overhaul cleaning to make it  more effective? or Does anyone have a sticking front brake system? This page will tell you that often times which i forgot for many years, the front brake system must be inspected and clean for a more reliable braking system of our motorcycle. So dammed fool of not having it inspected for so many years, that even thought the system still works without cleaning, The pad sticks to the brake rotor causing my front wheel not spinning freely. And so let the tear down begin.

First is to drain all the brake fluid using a hose and an empty plastic bottle of soda. insert first the close wrench number 8 on the brake caliper drain plug bolt and insert the hose to it.

This is to ensure no FLUID will be getting on your precious magwheels and paint. (corrosive substance) and all fluid will get to the plastic bottle. By opening the drain plug bolt, we can now release the brake fluid out from the reservoir by pressing the brake lever on and off until none of the fluid is visible. If you have an extra bottle of DOT-3 brake fluid, you may pour it on the reservoir to push all dirty brake fluid at the hoses and caliper itself so that fresh fluid will be at the hose and brake caliper when putting it all together again. You can also do this procedure later.

 After releasing all fluid inside the reservoir, , it is very difficult to take it out. After minutes of trying to remove it, finally the piston is out. Since this is i think the second time it has been remove in a 10 year span, the fluid already corroded some of it, in lieu with those white powder.

it can be remove from the handle bar and put it on a bench table for rework and general cleaning and inspection. Now the hard part, without the so called
This is a very bad sign, and i think in need of replacement but then this is a DIY page, so i'll still be reusing all of the parts. It will just be clean and remove unwanted debris.

NOTE:  But for readers, it is highly advisable to replace the whole piston assembly with new one. This is to ensure your front brake will not fail. The replacement part is very cheap. You can buy one at every friendly local shop available.

Here is a diagram of every component of the front brake master.

Continuing with the tear down, when the circlip that locks the piston to chamber was remove, the piston can be pulled out from it.

Here we can see the entire piston set of the brake master and photo says it all, YUCKY!!! too much dirt and sediments all over it. I wonder how it still works with that kind of dirt.

close up, that is the view of not totally having a routine check on the entire front brake system of a motorcycle.

Note again to the readers: If you find yourself like this on your motorcycle front braking system, please be advise to change it entirely. Do not re use for fail safe system.

Continuing with the process of my cleaning saga.

With the piston removed from the cylinder, cleaning the master reservoir only needs cloth that is damp with brake fluid. (use only brake fluid, no water, no soap) i used old toohbrush with NYLON bristles on cleaning the entire reservoir. The rest of the picture will tell how bad is this brake master.

and after minutes of cleaning the debris inside the chamber and the reservoir itself..patience makes a lot of difference, ready for assembly and bleeding the entire front braking system on this 125cc motorcycle.

when inserting back the piston to the cylinder. make sure you drop some brake fluid, this will help the primary and secondary cup sealed with the cylinder and glide normally inside of it. Lock the piston with the Circlip double check if is placed inside the groove. then put the dust cap back in its place.

we are now ready for bleeding, the act of removing old fluid inside the hoses and brake caliper.

Pour in fresh brake fluid onto the reservoir, make it full as in full tank. Press and release in cycle the brake lever and see the fluid gets in the hose. When doing this you will see bubbles when you are pressing the lever on and off. this means that the fluid is getting in. Make sure you are topping up when it goes to low level..Continue press and release the lever until it has already a slight tension to it..BLEEDING will come next.

When the lever got any tension on it..(i think you'll be needing someone to press that lever or if u can reach the bolt down while pressing the brake lever, I can call you that you a FANTASTIC man.. :) lol.

1. As you are pressing the brake lever,
2. open the drain plug to release the tension and push the fluid onto the drain plug. When there is no more fluid coming out from the drain hose we fitted onto the drain plug..close it again.and release the lever..press and release again the lever to get another tension and do it again the procedure on bleeding.

Do that procedure until all old fluid came out and that new fluid is coming out already.This is a sign that new fluid is already onto the system and you will have a tension on that front brake lever..

Top the reservoir on the correct level and return the DIAPHRAGM, the set plate and the cover and bolt it..The entire front brake system is done.

Now when you did cleaned the system and the front wheel is not spinning freely. Then the brake caliper is locking and in need of cleaning. The common problem with sticking disc brake is that, it does not return to the idle state when the piston of the caliper pushed the brake pad to the rotor..ROD that connects the caliper to its bracket as shown

This is the job of those number in 10, 15, 9, and 8. It needs to be cleaned.

photo shown next is where to put new grease so that when the caliper push the piston towards the brake pad..the grease will the push back the caliper to the idle state and releases the pad that is in contact with the brake rotor.

Good luck to your cleaning saga!!!..I have speed but without healthy BRAKING system...SPEED KILLS..

Last Updated: November 25, 2014

FD125XRM clutch repair (clutch basket)

Too many problems may be felt within the clutch system of small commuter motorcycles if it is not given some time to be checked at least every 5 years depending on the mileage and the way the motorcycle is driven. Nowadays, friction plates are getting cheaper. but the process of inspecting this critical part of any motorcycle is not an easy task especially if it is a multi-plate, wet clutch system. Often times, clutch drag and slipping clutch is a very common problem we may encounter.

Photo shown came from a 10 year old 125cc motorcycle, it was never been inspected up until this writing. The friction plate provided the groove to where the rest during operation. Notice the four groove s only at one side of the clutch basket (the other side do not actually have it, since the motorcycle is being kept moving forward and the rotation is always clockwise).

This photo shows how the friction plates and the steel plates are netted together inside the outer clutch basket.

They are stack in a friction plate followed by steel plates alternately, and is covered by the inner plate with the clutch spring attached to it.

If you want to know how this system works.You can watch it here to be familiar with it.

The Outer clutch basket i think is in lieu for replacement, but up to this writing, with no enough resources to do so, i will re use it and instead will be modifying it to accept an additional steel plate and another friction plate to make it a FIVE (5) piece clutch system..

Note: The whole procedure of the modification will not be discussed, for the stock clutch basket is not intended for an additional friction plates. Replacing washers, taking the tight clearances of the whole basket must be considered and any miscalculation on anyone's part will be a disastrous one inside the engine. So this modification is not for the masses. 

The next photo will reveal that it is indeed too tight for an additional friction plates and steel plates on a stock hub or stock clutch basket.

The look of the STOCK with four plates attached.

The look of the MODDED stock basket with five plates installed.

Now I know many of you will ask?

What is the ADVANTAGE of having a stock four friction plate on a modded five friction plate installed?

Ans: I did try to test drive it to see if i can still shift to any gears, that because of the tight spaces between the friction plate and the steel plate, as i read from the internet, only a small gap is needed to release the tension on each and one of them to DISENGAGED the whole clutch system from driving the the drive shaft.

The torque of power transfer within the system improves. The motorcycle now pulls a lot of it during uphill climb that even on my third gear..

(By the way the stock sprocket of my motorcycle is 14/35 to where it was change to 16/34 prior to the modded clutch system and do not pull at third gear on uphill with four piece friction plates.)

I wanted to test it on a stock combination to feel the difference but up to this moment i am enjoying the current 16/34 (low speed sprocket ratio)..

Again, the POWER TRANSFER of the crankshaft to the drive shaft by the clutch was improved.

Lesson to be learned from here is that.

1. Often times when you are replacing the FRICTION plates on your motorcycle when it is time for the replacement, be sure to check the outer basket for groove. The groove makes the friction plate stick on it, thereby making it difficult to shift at times..no many times, because when the plate is stuck they do not disengaged with the steel plates.So better check it.

2. Do not grind the groove, friction plate must not have slack on that area. if the groove is too much..replace the whole clutch basket, inner and outer is a MUST.

Last Updated: November 22, 2014

Motorcycle Camshaft Decompression Pin

We all know some motorcycle camshaft especially those SOHC engine have a so called Decompression cam or other called it Decompression Pin. But what it is really for what? Take a look at the picture of a shogun 125cc motorcycle equipped with this pin. The hook like pin located at the cam gear of the camshaft is the decompression pin. With that position (hook is resting towards the center, it is actually in the ON position. It already trigger the exhaust valve to open so that when we turned off the engine, the combustion chamber releases unwanted compressed mixture at the exhaust. This scenario makes it easier to start the engine by allowing fresh mixture to enter the chamber when we turned on the engine again. There is more, the unwanted kick back of the kick starter to which can cause injury when turning the engine by kick when the combustion chamber have leftover combustible mixture if this pin is not present.

Others find it difficult to understand why it was there, and they tend to remove this pin saving weight on their motorcycle in order to produce a little more top end, but what they do not actually know. As of my findings in my 10 year old shogun 125cc was. when my decompression pin stop operating normally due to the spacer break down as shown,
i have a real hard time starting it in the morning and kick always kick back to me, and so i decided to replace it with such that can cope the tromendous heat build up inside by handcrafting the spacer from a fiberglass PCB as shown.
I was so lucky that the broken plastic part of the valve train did not manage to create havoc inside my engine because it was trapped somewhere that i manage to pull out when i checked my clutch lining (an article is being written after this)..

I also found out that without the pin attached to the camshaft..and start the engine, abnormal vibration can be felt at the head area, and so i believe it has a function that when the camshaft is turning and the hook begins to move outwards near the edge of the cam gear due to INERTIA, it acts as a balancer of the camshaft for the hook part is against the LOBE of the cam.

So to those who are eyeing of removing this pin..take a closer look at the photo on how this part actually works. It was there for a reason., and removing this will not add you some extra HP or gain you some at the top end.

Last Updated: October 26, 2014

Motorcycle Charging For HID (full wave conversion)

Installing High Intensity Discharge on a small motorcycle which utilizes the Half Wave charging system will surely have lots of problem when it comes to battery not being charge to the fullest when using HID. This kind of lighting system actually not common to users consume a lot of current from striking the bulb all the way up to where it stabilizes. Even the re-striking from momentarily turning off the HID SYSTEM consumes battery power.

How to compensate for the loss of charge when using HID system?...The answer, by converting the original half wave system into a full wave generator, by altering the winding of the generator inside the crankcase. Looking at the graph of each type below.

By analyzing each of the graph generated by such system, it is very obvious that the full wave 3P when rectified and filtered produces a clean stable dc, that is why many sportsbike and higher displacement machine uses this kind of system. But why do they not used this on smaller bikes like moped and scooters.

Probably because of COST and size of the system. that is why manufacturers, instead relied on the low cost smaller size half wave generator system for carbureted type small machines. We cannot denied the fact, low cost means limited function.

Fuel injected nowadays been incorporated to small bikes like Shogun FI, honda scoopy I, and almost but not all bikes in thailand uses FI uses the three phase system already, so fitting HID system is of no trouble.

But how about to carbureted type?

It can be done, again by changing and converting it to full wave system to generate a more stable dc that will charge the onboard battery and compensate the losses done by the HID system..

FURTHERMORE, never insist the half wave system is enough for hid installation. It is simply not enough even if upgrading to a larger battery capacity.

Disclaimer: I will not held responsible if something goes wrong upon using this conversion without enough knowledge of how the system works, and electrical / technical skills at hand.. BE ADVISED that this modification is not intended for beginner or first time doing it. 

Getting deeper.

Materials needed.

  1. full wave rectifier / regulator (known as R / R too many) like this Full wave regulator 5 wire
  2. soldering iron at least 50-100watts
  3. high temp insulator tube  
  4. OPTIONAL : New crankcase cover gasket (when returning the modified stator and placing the cover back to the engine) 
  5. A digital or analog multimeter (tester too many)

IT is time to rock!!!

Remove the left crankcase cover to gain access on the stator

This stator is from a Suzuki SKYWAVE 125cc, same with shogun FD125XRM and Shogun FL125. There are three wire soldered to its connector base, find the ground by using a mutimeter set to OHMS , connect the black probe to the stator body and red probe to any of the three soldered wires.

The one with the lowest reading of the three is the wire connected directly to ground, with the highest being the end of the winding that will be used later, the last winding will not be used since it is the lighting coil output and will be disregarded all through out the procedure.

Remove the soldered wire to the stator body to FLOAT all windings...(all windings must not touch the body of the stator, full wave will have its own ground via the BRIDGE rectifier of the FULL wave regulator.)

With the ground wire desoldered from its original position, insert the high temperature tube and solder the wire removed from the lighting coil..

FOR SHOGUN its the yellow wire with white strip.

For other brand..please follow your wiring diagram.

what we trying to do here is getting the two end of the stator winding and removing the GROUND from the stator body as shown on the illustration.

when done, first is first..check for continuity and resistance of the whole winding before returning back the cover to ensure everything done is OK!!

Getting ready to wire the regulator from the modified generator

It is very difficult to know if the purchased R/R is a half wave or full wave if check only by appearance although manufacturers uses color coded wire like the photo shown, perhaps by using a diode tester (multimeters) and check every wire, we might be able to distinguished them. As i had told you, there are 4 pin and 5pin full wave available out in the market. If in a way you find such like as shown then probability is they are the same.

By following the color of the wires

  1. Green -- ground
  2. Red    -- to battery positive line
  3. Yellow -- to charging coil (any of the two winding out from the stator)
  4. Pink --- to charging coil (interchangeable with yellow)
  5. Black --- To after ignition key switch

To be sure and safe, for this test use appropriate FUSE  within the positive line going to the battery. its the last line of defense when it comes to possible wrong connection.

Disconnect all loads from the battery, if you have access to another way of supplying your CD ignition then do so..because we have to start the engine to perform TEST. with the help of the multimeter set to DC voltage. tap it to the battery that is connected to the regulator..

GREEN to black probe
RED to red probe

check voltage....you are reading the battery voltage, on the ignition key and take a look at value, after turning on the key engine OFF, the voltage must not be dropping and stay close to the initial reading.

kick the KICK starter, and stay it at idle, monitor the voltage. READING must now be moving up possible to 13 volts or 14 volts..(depends on the condition of the battery)..

SLOWLY REV the engine while monitoring the voltage reading of the tester.....

as you are revving the engine..voltage must stay close to 15 volts not over 16 volts (overcharging threshold of lead acid battery)..

if all test performed are ok with regulator not to temperature....PUT a load on the battery such as your HID installed...then start the SAME TEST again...

at first when you turn on the High intensity discharge system..at IDLE the voltage must not be dropping and will stay close to 12-13 volts..

if it is, then the system is already working..By looking at the graph above..FULL wave due to the better DC filtering, at idle or low rpm still charging the battery unlike the HALF wave where in the dc is fluctuating.

Full wave also has a better shunting than half wave to the configuration of the rectifying diodes.

NOW u can enjoy your HID system, just make sure you are responsible enough to stoop down the beam for others. happy motoring.

NOTE: since the lighting coil is disconnected and no longer used, all that was connected before will be redirected to the battery being battery operated.


For the full schematic diagram of the regulator on this article, you can visit this link


VIDEO of this conversion. (many thanks to Thiago Ken Fuzita)

Last Updated: October 12, 2014

Testing Motorcycle CDI Ignition Coil

CD ignition coil is a step up transformer that transform the voltage generated by the internal HV converter of a CDI into 20 to 40kv in order to achieve a spark at the tip of the plug. Do not be mistaken, CDI coil differs from TCI coil, and almost all available Ignition coil has only one purpose, To produce an arc to spark plug inside the combustion. Photo shown are some variants of ignition coil used on AC-CDI and DC-CDI. At top is china made ignition coil derived from a certain pioneer brand bike, center coil came from my GY6 scooter, and the bottom taken from my existing suzuki shogun 125cc commuter bike. The article will tell us the basic test of ignition coil, that is, resistance and inductance test. The benefits of knowing their resistance and inductance will tell us if the coil will be providing enough energy for our ignition beyond optimum level.

Primary winding compose of few turns thus resistance reading will show milliohms reading and almost zero  when using ordinary DVM, thus inductance may be a better choice for an instrument to test it, while as the secondary compose of a hundred turns, it is capable of resistance test.

here are the variation of reading of those three mentioned CDI coil above

The primary winding of the China made CD coil is about 34 uh, when i tried to take resistance test on this side, i only gain 0.3 ohms

for the GY6 coil, i got 29 uh still with a resistance of 0.3 ohms

and for my OEM ignition coil (suzuki shogun 125cc coil) got a reading of 66 uh but still with a reading of 0.3 ohms.

I did this test to be able to determine how it will affect my ignition before i tried to test it on board my motorcycle with the exception of my OEM. Yes they will all work since they are made for a CD ignition. and this inductance will primarily affect the transfer of energy towards the secondary winding of the coil.

For the secondary winding basic test, i use the resistance check, for my homemade inductance tester can only reach the 1 mh range.

Secondary resistance of the china made was 5.65 kohms

GY6 secondary winding resistance of 3.00 kohms

and OEM stands at 6.57 kohms

Higher resistance reading of the secondary means more number of turns and may transform it to a higher voltage output when the primary is being switched by the ignition controller, but then the primary winding also has an adverse effect on the secondary winding. Only by using HIGH voltage tester, we can assure of the reading, but because ignition coil are HIGHLY shield by epoxy resin, we cannot determine if the theory is in fact true that the more number of turns and higher resistance reading will produce more hotter spark.

Soon i will try to make an IGNITION COIL tester to see how the spark is generated by this three outside the combustion..

but then what we will see outside will differ if its inside due the pressure of the combustion. as of now resistance and inductance test is highly recommended for those who wants to try out different CDI coil available.

I am using by the way the china made coil, rather than my SHOGUN OEM, for a change. :-)