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Bottom view of the broken Yamaha LC135 engine

I have seen this picture in another website discussing about the reliability of Yamaha LC135 engine. Hit the links here for more picture and information.
RX-Z 2004 Catalyzer Exhaust Setup

Catalyzer is the technology used in Yamaha RX-Z 2004, Yamaha 125Z and also LC135. In order to know what is catalyzer, you need to know what is catalysis. So, read on this article quoted from Wikipedia.

Catalysis is the process in which the rate of a chemical reaction is increased by means of a chemical substance known as a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed. Thus, the catalyst may participate in multiple chemical transformations, although in practice catalysts are sometimes consumed in secondary processes.

Background

The production of most industrially important chemicals involves catalysis. Research into catalysis is a major field in applied science and involves many areas of chemistry, notably in organometallic chemistry, and materials science. Catalysis is important in many aspects of environmental science, from the catalytic converter in automobiles to the causes of the ozone hole. Catalytic reactions are preferred in environmentally friendly green chemistry due to the reduced amount of waste generated,[1] as opposed to stoichiometric reactions in which all reactants are consumed and more side products are formed. The most common catalyst is the proton (H+). Many transition metals and transition metal complexes are used in catalysis as well.

A catalyst works by providing an alternative reaction pathway to the reaction product. The rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst. The disproportionation of hydrogen peroxide to give water and oxygen is a reaction that is strongly affected by catalysts:

2 H2O2 → 2 H2O + O2

This reaction is favoured in the sense that reaction products are more stable than the starting material, however the uncatalysed reaction is slow. The decomposition of hydrogen peroxide is in fact so slow that hydrogen peroxide solutions are commercially available. Upon the addition of a small amount of manganese dioxide, the hydrogen peroxide rapidly reacts according to the above equation. This effect is readily seen by the effervescence of oxygen.[2] The manganese dioxide may be recovered unchanged, and re-used indefinitely, and thus is not consumed in the reaction. Accordingly, manganese dioxide catalyses this reaction.[3]

General principles of catalysis

Typical mechanism

Main article: catalytic cycle

Catalysts generally react with one or more reactants to form an intermediate that subsequently give the final reaction product, in the process regenerating the catalyst. The following is a typical reaction scheme, where C represents the catalyst, A and B are reactants, and D is the product of the reaction of A and B:

A + C → AC (1)
B + AC → ABC (2)
ABCCD (3)
CD → C + D (4)

Although the catalyst is consumed by reaction 1, it is subsequently produced by reaction 4, so for the overall reaction:

A + B → D

As a catalyst is regenerated in a reaction, often only small amounts are needed to increase the rate of the reaction. In practice, however, catalysts are sometimes consumed in secondary processes.

Catalysis and reaction energetics

Generic potential energy diagram showing the effect of a catalyst in an hypothetical exothermic chemical reaction. The presence of the catalyst opens a different reaction pathway (shown in red) with a lower activation energy. The final result and the overall thermodynamics are the same.

Generic potential energy diagram showing the effect of a catalyst in an hypothetical exothermic chemical reaction. The presence of the catalyst opens a different reaction pathway (shown in red) with a lower activation energy. The final result and the overall thermodynamics are the same.

Catalysts work by providing an (alternative) mechanism involving a different transition state and lower activation energy. The effect of this is that more molecular collisions have the energy needed to reach the transition state. Hence, catalysts can perform reactions that, albeit thermodynamically feasible, would not run without the presence of a catalyst, or perform them much faster, more specific, or at lower temperatures. This can be observed on a Boltzmann distribution and energy profile diagram. This means that catalysts reduce the amount of energy needed to start a chemical reaction.

Catalysts do not change the favorableness of a reaction: they have no effect on the chemical equilibrium of a reaction because the rate of both the forward and the reverse reaction are both affected (see also thermodynamics). The net free energy change of a reaction is the same whether a catalyst is used or not; the catalyst just makes it easier to activate.

The SI derived unit for measuring the catalytic activity of a catalyst is the katal, which is moles per second. The activity of a catalyst can also be described by the turn over number (or TON) and the catalytic efficiency by the turn over frequency (TOF). The biochemical equivalent is the enzyme unit. For more information on the efficiency of enzymatic catalysis see the Enzyme#Kinetics section.

Factors that affect catalytic rates

Catalysis manifests itself in accelerated rates of reactions, and thus many catalytic systems are analyzed with attention to how those rates are affected, beyond the usual parameters that affect all reactions, e.g. temperature, pressure, and concentration. In autocatalysis, a reaction produces catalysts, thus the rates of reactions subject to autocatalysis accelerate with time.

Some molecules inhibit catalysis by competing for the active sites. The strongest inhibitors are called poisons. Many catalysts used in petrochemical applications lose activity due to poisoning. Such catalysts are regenerated and reused multiple times to save costs and energy and to reduce environmental impact from disposal of spent catalysts.

In “product inhibition,” the rate of catalysis is slowed by the presence of products. When the equilibrium constant for a reaction is very high, however, rates can appear unaffected by the presence of products. In the catalytic hydrogenation of alkenes, for example, one does not observe inhibition by alkanes.

Typical catalytic materials

The chemical nature of catalysts is as diverse as catalysis itself, although some generalizations can be made. Proton acids are probably the most widely used catalysts, especially for the many reactions involving water, including hydrolyses and its reverse. Multifunctional solids often are catalytically active, e.g. zeolites, alumina, certain forms of graphitic carbon. Transition metals are often used to catalyse redox reactions (oxidation, hydrogenation). Many catalytic processes, especially those involving hydrogen, require platinum metals.

Some so-called catalysts are really “precatalysts.” Precatalysts convert to catalysts in the reaction. For example, Wilkinson’s catalyst RhCl(PPh3)3 loses one triphenylphosphine ligand before entering the true catalytic cycle. Precatalysts are easier to store but are easily activated in situ. Because of this preactivation step, many catalytic reactions involve an induction period.

Types of catalysis

Catalysts can be either heterogeneous or homogeneous, depending on whether a catalyst exists in the same phase as the substrate. Biocatalysts are often seen as a separate group.

Heterogeneous catalysts

Heterogeneous catalysts are present in different phases from the reactants. Most heterogeneous catalysts are solids that act on substrates in a liquid or gaseous reaction mixture. Diverse mechanisms for reactions on surfaces are known, depending on how the adsorption takes place (Langmuir-Hinshelwood and Eley-Rideal).[4]

For example, in the Haber process, finely divided iron serves as a catalyst for the synthesis of ammonia from nitrogen and hydrogen. The reacting gases adsorb onto “active sites” on the iron particles. Once adsorbed, the bonds within the reacting molecules are weakened, and new bonds between the resulting fragments form in part due to their close proximity. In this way the particularly strong triple bond in nitrogen is weakened and the hydrogen and nitrogen atoms combine faster than would be the case in the gas phase, so the rate of reaction increases.

Heterogeneous catalysts are typically “supported,” which means that the catalyst is dispersed on a second material that enhances the effectiveness or minimizes their cost. Sometimes the support is merely a surface upon which the catalyst is spread to increase the surface area. More often, the support and the catalyst interact, affecting the catalytic reaction.

Heterogeneous catalysts are often "supported" on complex structures to maximize surface area.

Heterogeneous catalysts are often “supported” on complex structures to maximize surface area.

Electrocatalysts

In the context of electrochemistry, specifically in fuel cell engineering, various metal-containing catalysts are used to enhance the rates of the half reactions that comprise the fuel cell. One common type of fuel cell electrocatalyst is based upon nanoparticles of platinum that are supported on slightly larger carbon particles. When this platinum electrocatalyst is in contact with one of the electrodes in a fuel cell, it increases the rate of oxygen reduction to water (or hydroxide or hydrogen peroxide).

Homogeneous catalysts

Main article: Homogeneous catalysis

Homogeneous catalysts function in the same phase as the reactants, but the mechanistic principles invoked in heterogeneous catalysis are generally applicable. Typically homogeneous catalysts are dissolved in a solvent with the substrates. One example of homogeneous catalysis involves the influence of H+ on the esterification of esters, e.g. methyl acetate from acetic acid and methanol.[5] For inorganic chemists, homogeneous catalysis is often synonymous with organometallic catalysts.

Organocatalysis

Main article: Organocatalysis

Whereas transition metals sometimes attract most of the attention in the study of catalysis, organic molecules without metals can also possess catalytic properties. Typically, organic catalysts require a higher loading (or amount of catalyst per unit amount of reactant) than transition metal-based catalysts, but these catalysts are usually commercially available in bulk, helping to reduce costs. In the early 2000s, organocatalysts were considered “new generation” and are competitive to traditional metal-containing catalysts. Enzymatic reactions operate via the principles of organic catalysis.

Significance of catalysis

Estimates are that 90% of all commercially produced chemical products involve catalysts at some stage in the process of their manufacture.[6] In 2005, catalytic processes generated about $900 billion in products worldwide.(pdf) Catalysis is so pervasive that subareas are not readily classified. Some areas of particular concentration are surveyed below.

Energy processing

Petroleum refining makes intensive use of catalysis for alkylation, catalytic cracking (breaking long-chain hydrocarbons into smaller pieces), naphtha reforming, steam reforming (conversion of hydrocarbons into synthesis gas). Even the exhaust from the burning of fossil fuels are treated via catalysis: Catalytic converters, typically composed of platinum and rhodium, break down some of the more harmful byproducts of automobile exhaust.

2 CO + 2 NO → 2 CO2 + N2

With regards to synthetic fuels, an old but still important process is the Fischer-Tropsch synthesis of hydrocarbons from synthesis gas, which itself is processed via water-gas shift reactions, catalysed by iron. Biodiesel and related biofuels require processing via both inorganic and biocatalysts.

Fuel cells rely on catalysts for both the anodic and cathodic reactions.

Heavy chemicals

Some of the largest scale chemicals are produced via catalytic oxidation, often using oxygen. Examples include nitric acid (from ammonia), sulfuric acid (from sulfur dioxide to sulfur trioxide by the chamber process), terephthalic acid from p-xylene, and acrylonitrile from propane and ammonia.

Many other chemical products are generated by large-scale reduction, often via hydrogenation. The largest-scale example is ammonia, which is prepared via the Haber process from nitrogen. Methanol is prepared from carbon monoxide.

Bulk polymers derived from ethylene and propylene are often prepared via Ziegler-Natta catalysis. Polyesters, polyamides, and isocyanates via acid-base catalysis.

Most carbonylation processes require metal catalysts, examples include the Monsanto acetic acid process and hydroformylation.

Fine chemicals

Many fine chemicals are prepared via catalysis; methods include those of heavy industry as well as more specialized processes that would be prohibitively expensive on a large scale. Examples include olefin metathesis using Grubbs’ catalyst, the Heck reaction, and Friedel-Crafts reactions.

Because most bioactive compounds are chiral, many pharmaceuticals are produced by enantioselective catalysis.

Food processing

One of the most obvious applicatoins of catalysis is the hydrogenation (reaction with hydrogen gas) of fats using nickel catalyst to give margarine.[7] Many other foodstuffs are prepared via biocatalysis (see below).

Biology

Main article: Biocatalysis

In nature, enzymes are catalysts in metabolism and catabolism. Most biocatalysts are protein-based, i.e. enzymes, but other classes of biomolecules also exhibit catalytic properties including abzymes, ribozymes, and synthetic deoxyribozymes.

Biocatalysts can be thought of as intermediate between homogenous and heterogeneous catalysts, although strictly speaking soluble enzymes are homogeneous catalysts and membrane-bound enzymes are heterogeneous. Several factors affect the activity of enzymes (and other catalysts) including temperature, pH, concentration of enzyme, substrate, and products. A particularly important reagent in enzymatic reactions is water, which is the product of many bond-forming reactions and a reactant in many bond-breaking processes.

Enzymes are employed to prepare many commodity chemicals including high-fructose corn syrup and acrylamide.

In the environment

Catalysis impacts the environment by increasing the efficiency of industrial processes, but catalysis also directly plays a direct role in the environment. A notable example is the catalytic role of Chlorine free radicals in the break down of ozone. These radicals are formed by the action of ultraviolet radiation on chlorofluorocarbons (CFCs).

Cl· + O3 → ClO· + O2
ClO· + O· → Cl· + O2

History

In a general sense, anything that increases the rate of any process is often called a “catalyst,”a term derived from Greek καταλύειν, meaning “to annul,” or “to untie,” or “to pick up.” The phrase catalysed processes was coined by Jöns Jakob Berzelius in 1836[8] to describe reactions that are accelerated by substances that remain unchanged after the reaction. Other early chemists involved in catalysis were Alexander Mitscherlich who in 1831[citation needed] referred to contact processes and Johann Wolfgang Döbereiner who spoke of contact action and whose lighter based on hydrogen and a platinum sponge became a huge commercial success in the 1820’s. Humphrey Davy discovered the use of platinum in catalysis. In the 1880s, Wilhelm Ostwald at Leipzig University started a series of systematic investigations into reactions that were catalyzed by the presence of acids and bases, and found both that chemical reactions occur at finite rates, and that these rates can be used to determine the strengths of acids and bases. For this work, Ostwald was awarded the 1909 Nobel Prize in Chemistry.[9]

See also

References

  1. ^The 12 Principles of Green Chemistry“. United States Environmental Protection Agency. Retrieved on 200607-31.
  2. ^Genie in a Bottle“. University of Minnesota (200503-02).
  3. ^ Masel, Richard I. “Chemical Kinetics and Catalysis” Wiley-Interscience, New York, 2001. ISBN 0471241970.
  4. ^ Helmut Knözinger, Karl Kochloefl “Heterogeneous Catalysis and Solid Catalysts” in Ullmann’s Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a05_313. Article Online Posting Date: January 15, 2003
  5. ^ Arno Behr “Organometallic Compounds and Homogeneous Catalysis” Ullmann’s Encyclopedia of Industrial Chemistry, 2002, Wiley-VCH, Weinheim. doi:10.1002/14356007.a18_215. Article Online Posting Date: June 15, 2000
  6. ^ “Recognizing the Best in Innovation: Breakthrough Catalyst”. R&D Magazine, September 2005, pg 20.
  7. ^Types of catalysis“. Chemguide. Retrieved on 200807-09.
  8. ^ K.J. Laidler and J.H. Meiser, Physical Chemistry, Benjamin/Cummings (1982), p.423
  9. ^ M.W. Roberts (2000). “Birth of the catalytic concept (1800-1900)“. Catalysis Letters 67 (1): 1–4. doi:10.1023/A:1016622806065.

External links

Look up Catalysis in
Wiktionary, the free dictionary.

Today, when I just checked the visitor to my blog, I found an interesting visits from Honda R&D Co., Ltd. Wako R&D Center in Wako, Saitama, Japan. The one thing that makes this thing interesting is because Honda R&D has made a search in Google about Yamaha 125 ZR specifications.
Since this came from Honda R&D, I think, they were researching for their upcoming 125cc 2-stroke bike to beat Yamaha 125ZR.
The present bike from Honda with 125cc and 2-stroke are Honda Nova Dash.




I have found a Daiichi Alloy Sport Rims Catalogue here. As we all know, Daiichi Alloy is made from Thailand and that is a good reason to buy it. This is due to the fact that Thais really like to modified their bike to the extreme. Also, it is cheaper than to buy Enkei rims. Even though it is cheap, it is proven to be safe and reliable as it is used in races in Thailand.

Enjoy the sport rims model for 125Z, EX-5, RX-Z and many more.


RX-Z CDI Unit Assy

Capacitor discharge ignition (CDI) or thyristor ignition is a type of automotive electronic ignition system which is widely used in motorcycles, lawn mowers, chain saws, small engines, Turbine powered aircraft, and some cars. It was originally developed to overcome the long charging times associated with high inductance coils used in inductive ignition systems, making the ignition system more suitable for high engine speeds (for small engines, racing engines and rotary piston engines). Capacitor discharge ignition uses capacitor discharge current output to fire the spark plugs.

History

The history of capacitor discharge ignition system can be traced back to the 1950s together with the development of other electronic ignition systems. The first commercial motorcycle using the CDI system was manufactured by Kawasaki.

By the end of 1960s, the US government made new laws enforcing strict emission standards. As a result, more and more electronic ignition systems were developed, and starting from 1970s all smaller engines installed CDI system to replace the contact point system, including Honda Cub which began to use AC-CDI system.

The basic principle

Most ignition systems used in cars are inductive ignition systems, which are solely relying on the electric inductance at the coil to produce high-voltage electricity to the spark plugs as the magnetic field breaks down when the current to the primary coil winding is disconnected (disruptive discharge). In a CDI system, a charging circuit charges a high voltage capacitor, and during the ignition point the system stops charging the capacitor, allowing the capacitor to discharge its output to the ignition coil before reaching the spark plug.

A typical CDI module consists of a small transformer, a charging circuit, a triggering circuit and a main capacitor. First, the system voltage is raised up to 400-600 V by a transformer inside the CDI module. Then, the electric current flows to the charging circuit and charges the capacitor. The rectifier inside the charging circuit prevents capacitor discharge before the ignition point. When the triggering circuit receives triggering signals, the triggering circuit stops the operation of the charging circuit, allowing the capacitor to discharge its output rapidly to the low inductance ignition coil, which increase the 400-600 V capacitor discharge to up to 40 kV at the secondary winding at the spark plug. When there’s no triggering signal, the charging circuit is re-connected to charge back the capacitor.

The amount of energy the CDI system can store for the generation of a spark is dependent on the voltage and capacitance of the capacitors used, but usually it’s around 50 mJ.

Most CDI modules are generally of two types:

  • AC-CDI – The AC-CDI module obtains its electricity source solely from the alternating current produced by the alternator. The AC-CDI system is the most basic CDI system which is widely used in small engines.

Note that not all small engine ignition systems are CDI. Some older engines, and engines like older Briggs and Stratton use magneto ignition. The entire ignition system, coil and points, are under the magnetized flywheel.

Another sort of ignition system commonly used on small off-road motorcycles in the 1960s and 1970’s was called Energy Transfer. A coil under the flywheel generated a strong DC current pulse as the flywheel magnet moved over it. This DC current flowed through a wire to an ignition coil mounted outside of the engine. The points sometimes were under the flywheel for two-stroke engines, and commonly on the camshaft for four-stroke engines. This system worked like all Kettering (points/coil) ignition systems… the opening points trigger the collapse of the magnetic field in the ignition coil, producing a high voltage pulse which flows through the spark plug wire to the spark plug.

If the engine was rotated while examining the wave-form output of the coil with an oscilloscope, it would appear to be AC. But you must consider that since the charge-time of the coil corresponds to much less than a full revoltion of the crank, the coil really ‘sees’ only DC current for charging the external ignition coil.

There exist some electronic ignition systems that are not CDI. Some systems use a transistor to switch the charging current to the coil off and on at the appropriate times. This eliminated the problem of burned and worn points, and provided a hotter spark because of the faster voltage rise and collapse time in the ignition coil.

  • DC-CDI – The DC-CDI module is powered by the battery, and therefore an additional DC/AC inverter circuit is included in the CDI module to raise the 12 V DC to 400-600 V DC, making the CDI module slightly larger. However, vehicles that use DC-CDI systems have more precise ignition timing and the engine can be started more easily when cold.

Advantages and Disadvantages of CDI

A CDI system has a short charging time, a fast voltage rise (between 3 ~ 10 kV/μs) compared to typical inductive systems (300 ~ 500 V/μs) and a short spark duration limited to about 50-80 µs. The fast voltage rise makes CDI systems insensitive to shunt resistance, but the limited spark duration can for some applications be too short to provide reliable ignition. The insensitivity to shunt resistance and the ability to fire multiple sparks can provide improved cold starting ability.

Since the CDI system only provides a short spark, it’s also possible to combine this ignition system with ionization measurement. This is done by connecting a low voltage (about 80 V) to the spark plug, except when fired. The current flow over the spark plug can then be used to calculate the temperature and pressure inside the cylinder.

References

This article is quoted from Wikipedia.

Coming soon, how racing cdi unit can really boost up the performance of the engine. Stay tuned!

RX-Z 100S

RX-Z started its production in 1980’s. At that time there are two version of RX-Z, namely RX-Z 100 and RX-Z 135. RX-Z 100 was specifically designed to fit the market in Mexico only, therefore we didn’t have it here in Malaysia. RX-S 100 and RX-S 115 was the common bike that we see before the introduction of the legendary RX-Z 135.

RX-Z 135 was introduced at that time with 5-speed transmission, box speedometer and straight exhaust pipe without the resonance chamber. Even though the design is created almost 27 years back, but it still relevant in today’s motorcycle environment. The design is still fresh and amazing. Given the power of 135 cc with 2-stroke class engine makes it a very intimidating bike. In year 1985, people who buys the RX-Z 135 is said to have a fun lifestyles, macho and having daring personality. RX-Z 135 design also is very futuristic compared to the bike such as Honda Raider, Suzuki Katana, X7 and Kawasaki GTO. RX-Z 135 is known for their awesome power can be harnessed easily just by a little modification. The most popular and cheapest modification with great performance boost is done by changing the exhaust pipe to a racing exhaust pipe. A good racing pipe can add up to 3 ps. This can be achieved if the exhaust pipe have a good resonance chamber that can works likes a mini turbo without the turbine. But, even in standard condition, the bike can go up to 150 km/h and that is higher than the highway speed limit here in Malaysia (110 km/h). Most of the RX-Z 135 owner here have modified their bike to go up to 200++ km/h and they used it for daily commute and mind you, it is not for racing. Speed is one of the reason why RX-Z 135 is very popular because we need it to overtake big lorries and heavy trucks during the commute using highway or specifically in PLUS highway here in Malaysia.

In 1990, Yamaha makes a little upgrade to the bike by adding one more gear to the transmission that makes the bike 6-speeder. The design of the exhaust pipe has been updated by equipping it with a new design that have resonance chamber and muffler. This design have increased the power of the bike to 21 ps. Still at this period of time, there are no bike manufactured by other company that beat RX-Z. In fact, there IS no bike by other manufacturer that has been build to be in the same category as RX-Z 135. Most manufacturer like to focus their bike to 150 cc segment. This is true when we look at Suzuki Gamma 150 cc, Honda NSR 150RR and Kawasaki KIPS 150, but here Yamaha also its own weapon that is TZM 150.

2000 has been the year RX-Z get a new cloth. RX-Z has been refreshed with new head and tail design. The new head gets a new smaller headlight. The turn signal has been integrated to the cowling, thus making the bike looks cleaner and more meaner. Tail light has been borrowed from 125Z, but it is okay since the tail light is also nice and clean. But. I prefer for Yamaha to make an original tail light design specifically for RX-Z 135. Clutch has also been upgraded by Yamaha making it is easier to switch gears and better handling for low speed travelling.

Even with lots of reason to be popular, RX-Z is not a bike without flaw. The greatest flaw that I can think of is, the position of the carburetor and the way it is assembled. Since the carburetor is only hold up by 2 connecting rubber, it is very easy to take the carburetor off. And this give way to thief to take it easily. Even if the thief won’t take the carburetor off, they can still steal the petrol from the RX-Z tank since the fuel line is exposed at the left side of the carburetor. I have heard a lot of complain about this from my friends and also from other RX-Z owners.

2008 is a year we all wait for Yamaha to unveil new RX-Z 135 design or at least stripe change.

Here’s the year and code name model change that RX-Z 135 have gone through:

1st model:
1985/87 – 2UX

2nd model:
1989 – 3UK1

3rd model:
1993 – 3UK3

4th model:
1995 – 3RSA

5th model:
1996/97 – 3RSB

6th model:
2000 – 3XL3

7th model:
2002 – 5PV1

8th model:
2005 – 5PV2

9th model:
2008- ??? (not yet introduced)
What is expected in 2008/09 RX-Z model:
Rear mono-shock suspension
Rear disc brake
Inverted front telescopic fork
Double piston front brake caliper
New stripe and design
New & original sports rim equipped

but, you should know that Malaysia already have stopped the introduction of new 2-stroke bike starting the year 2006. So, there are no more new RX-Z model. We will only stick to 5PV2 for the rest of the time.

Long Live RX-Z!

Arkib

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