The required tightening values for the fasteners securing the cylinder head on a small-displacement, four-stroke engine generally present in all-terrain autos manufactured in China, particularly these with a 125cc engine measurement, are essential for correct engine operate and longevity. These values, usually expressed in Newton-meters (Nm) or foot-pounds (ft-lbs), dictate the quantity of rotational pressure to be utilized when tightening the pinnacle bolts. An instance can be tightening the bolts in a sequence, beginning on the middle and dealing outwards, to a primary go of 10 Nm, adopted by a second go of 20 Nm.
Adhering to the proper specs is paramount for a number of causes. Inadequate torque can result in combustion gasoline leaks, lowered engine energy, and potential overheating. Conversely, extreme torque can harm the cylinder head, strip the bolt threads, or distort the cylinder head, leading to related efficiency points and dear repairs. Understanding these specs ensures optimum sealing between the cylinder head and the engine block, thereby sustaining correct compression and environment friendly combustion. Traditionally, producers have usually used related engine designs, however delicate variations in supplies and manufacturing processes necessitate adherence to the exact torque settings for a particular engine.
Due to this fact, finding and precisely making use of the proper tightening values is important when servicing or rebuilding this explicit engine sort. This includes consulting the producer’s service handbook or dependable on-line sources to acquire the exact figures and tightening sequence. Utilizing a calibrated torque wrench can be crucial to make sure correct utility of the required rotational pressure throughout the tightening course of. Ignoring or misapplying these specs can result in vital engine harm and lowered efficiency.
1. Correct Tightening
Within the realm of inner combustion, a single oversight can cascade into mechanical calamity, particularly throughout the unassuming structure of a Chinese language 125cc ATV engine. Correct tightening, the meticulous utility of rotational pressure, is the linchpin connecting the pinnacle bolt torque specs to the engine’s operational well being. It’s not merely about turning a wrench; it is about orchestrating a symphony of stress and compression, important for the engine’s very survival.
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The Dance of Pressure: Sealing the Combustion Chamber
The first function of correct tightening is to create an hermetic seal between the cylinder head and the engine block. Insufficient torque permits combustion gases to flee, resulting in energy loss, overheating, and potential detonation. Think about the engine as a strain cooker; a defective seal renders all the system ineffective and doubtlessly harmful. This leak is a direct results of failing to stick to the pinnacle bolt torque specs. A correctly tightened head, nonetheless, ensures that every one the facility generated is channeled via the piston, driving the ATV ahead. Actual-world penalties embrace engine failure throughout operation.
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Even Distribution: The Artwork of Sequencing
Tightening the pinnacle bolts within the right sequence is as crucial as making use of the proper torque worth. This ensures that the clamping pressure is distributed evenly throughout the cylinder head, stopping warping or distortion. Image a bridge; if the helps should not uniformly burdened, all the construction will collapse. Likewise, uneven tightening can harm the pinnacle gasket and result in catastrophic engine failure. Producers usually suggest a criss-cross sample, tightening the bolts in phases to progressively compress the gasket and create a uniform seal. Ignoring sequence results in sizzling spots, and stress factors that will result in engine failure.
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Past Torque: Contemplating Bolt Integrity
Correct tightening is not solely in regards to the numbers on a torque wrench; it includes assessing the situation of the bolts themselves. Stretched or broken bolts can compromise all the tightening course of. Such bolts can yield prematurely, even when tightened to the required torque, resulting in a lack of clamping pressure over time. Changing outdated or questionable bolts with new ones is a small funding that may forestall vital engine harm. This step is especially essential for engines which have been beforehand disassembled or overheated, as these circumstances can weaken the bolts. Utilizing the correct bolt materials is paramount to move bolt torque specs.
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The Precision of Calibration: The Torque Wrench’s Story
A torque wrench is just not merely a software; it is an instrument of precision. A poorly calibrated torque wrench can present deceptive readings, resulting in over- or under-tightening. Over-tightening can strip the threads within the engine block or harm the cylinder head, whereas under-tightening may end up in combustion leaks. Common calibration of the torque wrench is important to make sure accuracy. This straightforward act can save an engine from untimely failure and untold frustration. Counting on really feel, as an alternative of the correct torque specs, will end in engine failure.
In summation, correct tightening is just not an remoted activity however an built-in course of, inextricably linked to the pinnacle bolt torque specs of a Chinese language 125cc ATV engine. It encompasses right torque values, exact tightening sequences, bolt integrity, and the accuracy of the instruments used. Neglecting any considered one of these parts can have profound penalties, remodeling a dependable machine right into a supply of mechanical woes. The saga of a well-maintained engine is usually the story of correctly tightened bolts, a testomony to the facility of precision and a spotlight to element.
2. Torque Worth (Nm/ft-lbs)
Within the sprawling panorama of mechanical engineering, a humble quantity, the torque worth, usually measured in Newton-meters (Nm) or foot-pounds (ft-lbs), holds immense energy. Throughout the context of a Chinese language 125cc ATV engine, this quantity dictates the lifespan and efficiency of the machine. These values are a cornerstone of the pinnacle bolt torque specs, representing the exact rotational pressure required to safe the cylinder head to the engine block. This seemingly easy parameter is the important thing to making sure a gas-tight seal, stopping leaks, and sustaining optimum compression, that are all important for environment friendly combustion. With out correct torque values, the engine is a bet; a sport of probability with excessive stakes.
Think about the story of a rural mechanic, a veteran of numerous engine rebuilds. He acquired a Chinese language 125cc ATV engine with a blown head gasket, a standard downside in these smaller engines. The proprietor, an area farmer, had tried to restore it himself, utilizing “really feel” relatively than a torque wrench. The consequence was catastrophic: the pinnacle bolts have been erratically tightened, inflicting the gasket to fail inside just a few hours of operation. The mechanic, adhering strictly to the producer’s torque specs, meticulously tightened the pinnacle bolts within the right sequence. The engine roared again to life, performing reliably for years. This real-world state of affairs underscores the significance of adhering to the required torque worth; it isn’t only a quantity, it is a crucial aspect that protects the engine from untimely failure.
The problem lies in acquiring the proper torque worth for a particular engine mannequin. These values should not common; they range based mostly on engine design, supplies used, and the scale of the bolts. Accessing the producer’s service handbook or consulting dependable on-line sources is paramount. Moreover, understanding the restrictions of the instruments used, notably the torque wrench, is essential. A poorly calibrated torque wrench can result in disastrous outcomes, whatever the operator’s talent. The torque worth, due to this fact, isn’t just a quantity; it represents a fastidiously engineered parameter, demanding respect and precision. Appropriately making use of this worth unlocks the potential of the Chinese language 125cc ATV engine, guaranteeing years of dependable service.
3. Tightening Sequence
The engine stood silent, a metallic monolith awaiting resurrection. A Chinese language 125cc ATV engine, sufferer to a poorly executed restore. The mechanic, seasoned by years of wrestling with recalcitrant equipment, approached with a measured calm. The pinnacle bolt torque specs lay open on the workbench a testomony to the unforgiving precision demanded by inner combustion. Nevertheless it was not merely the numbers, the foot-pounds or Newton-meters, that held the important thing. It was the sequence. The tightening sequence, an often-overlooked aspect within the grand scheme of engine restore, was the silent conductor of this metallic orchestra.
The implications of ignoring the required sequence are profound. Image the cylinder head as a fragile plate, laid atop the engine block. Every bolt, when tightened, exerts a pressure. If these forces are utilized haphazardly, in a random or illogical order, the plate will warp, distort, and fail to seal correctly. Combustion gases will escape, compression will falter, and the engine will cough its final breath. The required sequence, usually a spiral sample emanating from the middle outwards, ensures that this pressure is distributed evenly, compressing the pinnacle gasket uniformly. This uniform compression creates a gas-tight seal, important for environment friendly combustion and engine longevity. There are quite a few tales in any engine store, the place mechanics lower the nook, and skip the tightening sequence. However the Chinese language 125cc ATV engine has unforgiving tolerances, and improper tightening sequence would spell catastrophe.
The tightening sequence, due to this fact, is just not a mere suggestion, however a crucial part of the pinnacle bolt torque specs. It’s the roadmap that guides the mechanic via the method, guaranteeing that every bolt performs its half in concord with the others. A torque wrench alone is inadequate. The sequence supplies the essential context, remodeling a group of numbers right into a fastidiously orchestrated tightening process. With out it, the engine stays susceptible, a testomony to the significance of element and precision. It’s in these exact steps that the center of the engine involves life.
4. Bolt Situation
The weathered engine block, a relic from numerous off-road excursions, stood as a somber reminder of mechanical neglect. A Chinese language 125cc ATV engine, its destiny hanging within the stability. The pinnacle bolt torque specs, printed on a grease-stained sheet, provided a path to redemption. However the numbers alone couldn’t assure success. The essential, usually neglected, issue lay within the situation of the bolts themselves. Every bolt, a silent witness to the engine’s historical past, possessed a narrative etched in its very metallic. Have been they fatigued, stretched, corroded? Their situation instantly impacted the accuracy and effectiveness of any torque utilized. These information have been additionally impacted by head bolt torque specs chinese language 125cc atv engine.
Think about the story of two engines, almost an identical in age and utilization. Within the first, the mechanic meticulously cleaned and inspected every bolt, discarding any that confirmed indicators of damage or harm. He then utilized the pinnacle bolt torque specs with precision, assured within the integrity of the fasteners. The engine purred to life, its future shiny. Within the second engine, the mechanic, pressed for time, reused the outdated bolts with out correct inspection. He utilized the identical torque specs, however the outcomes have been disastrous. The stretched bolts yielded prematurely, failing to offer the required clamping pressure. Combustion gases leaked, the engine overheated, and the restore proved futile. This narrative illustrates a basic fact: the pinnacle bolt torque specs are solely as dependable because the bolts themselves. Their situation dictates their potential to resist the utilized pressure and preserve the essential seal between the cylinder head and the engine block. The fitting specs are wasted on worn bolts.
Due to this fact, understanding and addressing the situation of the pinnacle bolts is just not merely a finest observe; it’s a necessity. Changing questionable bolts with new ones, guaranteeing they’re of the proper grade and size, is a small funding that may forestall vital engine harm. The pinnacle bolt torque specs present the blueprint, however the bolt situation determines the structural integrity of the engine. Collectively, they kind a symbiotic relationship, important for the dependable operation of a Chinese language 125cc ATV engine. Neglecting this relationship is akin to constructing a home on a weak basis: the results are inevitable. Appropriate bolt situation is paramount with the proper head bolt torque specs chinese language 125cc atv engine.
5. Thread Lubrication
The veteran mechanic, a person whose arms bore the map of numerous engine rebuilds, paused, a drop of oil clinging to the tip of his index finger. Earlier than him lay a Chinese language 125cc ATV engine, stripped naked, awaiting reassembly. The pinnacle bolt torque specs, meticulously researched and printed, have been close by. Nevertheless it wasn’t the numbers etched on the web page that commanded his speedy consideration; it was the threads. Clear, dry threads. The absence of lubrication, a seemingly minor element, may unravel essentially the most exact torque calculations.
The connection between thread lubrication and the required torque values for these engines is just not merely educational; it is a basic facet of correct bolt tightening. Torque, as a measure of rotational pressure, is used to create clamping pressure – the pressure that holds the cylinder head firmly towards the engine block. Nonetheless, a good portion of the utilized torque is expended overcoming friction between the bolt threads and the threads throughout the engine block. Dry threads generate considerably extra friction than lubricated threads. Consequently, if a torque worth is utilized to dry threads, the ensuing clamping pressure will likely be decrease than meant, doubtlessly resulting in combustion leaks and engine harm. An area ATV restore store found this firsthand when a collection of rebuilt engines started experiencing untimely head gasket failures. Investigation revealed that the technicians, in an effort to “be clear,” had skipped the lubrication step. The following value in elements and labor was a stark lesson within the significance of lubrication. It’s why the pinnacle bolt torque specs chinese language 125cc atv engine should all the time be carried out with the proper lubricant.
Due to this fact, thread lubrication is just not non-obligatory; it is an integral a part of the pinnacle bolt torque specs for these engines. The kind of lubricant used can be crucial. The producer usually specifies a selected sort of oil or anti-seize compound, and deviations from this advice can have an effect on the ultimate clamping pressure. By decreasing friction, the proper lubricant ensures {that a} higher proportion of the utilized torque is transformed into clamping pressure, making a stronger, extra dependable seal. Ignoring this element can rework a seemingly easy activity right into a recipe for mechanical catastrophe. Guaranteeing the bolt’s threads have the proper lubrication goes hand in hand with right head bolt torque specs chinese language 125cc atv engine, or the job is finished incorrectly.
6. Torque Wrench Calibration
The small engine, a Chinese language 125cc ATV powerplant, represented each alternative and peril. Alternative for dependable transportation, peril if the reassembly, now imminent, was executed with something lower than surgical precision. On the coronary heart of that precision lay the torque wrench, a software promising accuracy. However a software, like all instrument, can deceive. The pinnacle bolt torque specs chinese language 125cc atv engine demanded respect, however respect began not simply with realizing the numbers, however with trusting the software delivering them, that’s, realizing the torque wrench calibration.
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The Unseen Drift: The Perils of Uncalibrated Instruments
A torque wrench, over time and use, undergoes a delicate, insidious drift. Springs weaken, mechanisms put on, and the digital show glints with uncertainty. This drift introduces error, remodeling the prescribed torque worth from a exact instruction right into a mere approximation. The anecdote of a seasoned mechanic rebuilding a fleet of ATVs serves as a cautionary story: satisfied of his torque wrench’s accuracy, he routinely skipped calibration. A collection of untimely head gasket failures adopted, every traced again to inadequate clamping pressure ensuing from the instruments diminished precision. With out calibration, the wrench’s promise of accuracy is a phantom, undermining essentially the most meticulous effort.
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The Chain of Accuracy: Linking Calibration to Engine Longevity
Correct calibration establishes a sequence of accuracy, connecting the producer’s torque specs to the precise pressure utilized to the pinnacle bolts. This chain is simply as robust as its weakest hyperlink, and a poorly calibrated wrench turns into that weak hyperlink. The method of calibration includes evaluating the wrench’s output to a recognized commonplace, adjusting its inner mechanisms to make sure its readings are correct. This painstaking course of closes the loop, guaranteeing that the engine receives the exact clamping pressure required for optimum efficiency and longevity. Within the absence of this course of, the pinnacle bolt torque specs chinese language 125cc atv engine turns into a random suggestion, as an alternative of particular instruction.
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The Price of Neglect: Untimely Failures and Wasted Sources
Neglecting torque wrench calibration carries a hidden, however vital, value. Over-tightening, born from an inaccurate wrench, can strip threads, warp cylinder heads, and harm costly elements. Underneath-tightening results in combustion leaks, lowered engine energy, and potential overheating. Each eventualities end in untimely engine failures, requiring pricey repairs and downtime. The value of calibration, a comparatively small funding, pales compared to the potential monetary burden of neglecting this significant step. Common and well timed torque wrench calibration helps scale back value. Failing to stick to the pinnacle bolt torque specs chinese language 125cc atv engine results in harm.
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The Ritual of Verification: Establishing a Tradition of Precision
Torque wrench calibration shouldn’t be considered as a chore, however as a ritual an important step in establishing a tradition of precision inside any engine restore course of. Common calibration intervals, documented data, and clear procedures reveal a dedication to high quality and accuracy. This dedication instills confidence, guaranteeing that the reassembly is carried out to the very best requirements. It transforms the straightforward act of tightening a bolt right into a acutely aware affirmation of engineering ideas, a respect for tolerances, and a dedication to lasting efficiency. Torque Wrench Calibration reveals that you already know head bolt torque specs chinese language 125cc atv engine.
Ultimately, the mechanic, reassured by the freshly calibrated torque wrench, tightened every head bolt with unwavering confidence. The engine, a testomony to precision and care, roared again to life. This was not merely a restore, however an illustration of the facility of accuracy, the significance of calibration, and the enduring worth of respecting the pinnacle bolt torque specs chinese language 125cc atv engine.
Regularly Requested Questions
These often requested questions deal with widespread issues and misconceptions concerning the crucial strategy of correctly torquing the cylinder head bolts on Chinese language-manufactured 125cc ATV engines. Misunderstanding can result in catastrophic engine failure; therefore, meticulous consideration to element is paramount.
Query 1: Why are the tightening values for the cylinder head bolts so essential on these explicit engines?
Think about the destiny of a younger fanatic who disregarded these values. Lured by the attract of a fast repair, he tightened the pinnacle bolts “by really feel” on his Chinese language 125cc ATV. The consequence? A catastrophic engine failure inside every week, the threads stripped, the cylinder head warped past restore. These engines, whereas inexpensive, possess tighter tolerances, rendering correct torque utility non-negotiable. The required tightening values are the very basis upon which the engine’s integrity rests.
Query 2: How does one get hold of the proper tightening values, and is there a common worth for all Chinese language 125cc ATV engines?
The hunt for the proper values resembles a treasure hunt. There isn’t any common key; every engine variant possesses its personal distinctive code. One should seek the advice of the producer’s service handbook, a doc usually neglected however indispensable. On-line boards and skilled mechanics can provide steerage, however warning is suggested; confirm data meticulously. Counting on generic values is a bet with doubtlessly dire penalties; what could seem proper may very well be the prelude to catastrophe.
Query 3: What occurs if the bolts are tightened past the required values?
Think about a blacksmith, hammering metallic with extreme pressure. The metallic yields, deforms, and in the end cracks. Over-tightening head bolts inflicts related trauma. The threads within the engine block, designed to resist a particular pressure, are stretched and weakened. The cylinder head itself can warp, compromising the crucial seal. The result’s usually a stripped thread, rendering the engine block unusable. Restraint and precision are virtues, not weaknesses, on this endeavor.
Query 4: Is the tightening sequence really vital, or can the bolts be tightened in any order?
The tightening sequence is just not merely a suggestion; it’s an orchestration of pressure. Visualize a spiderweb, every strand contributing to the general construction. Tightening the pinnacle bolts out of sequence is akin to plucking the strands haphazardly, disrupting the net’s integrity. The cylinder head, a fragile plate, requires even distribution of clamping pressure. A correct sequence, usually a spiral sample emanating from the middle, ensures that this pressure is utilized uniformly, stopping warping and guaranteeing a gas-tight seal.
Query 5: Does the situation of the bolts matter, or can the outdated bolts be reused indefinitely?
Think about the analogy of a rubber band, stretched repeatedly over time. It loses its elasticity, its potential to return to its authentic form. Head bolts, subjected to excessive warmth and strain cycles, expertise related fatigue. Reusing outdated, stretched bolts is a bet. They could seem sound, however their potential to keep up clamping pressure is compromised. Changing them with new, high-quality bolts is a small worth to pay for peace of thoughts.
Query 6: Is lubrication of the bolt threads vital, and in that case, what sort of lubricant needs to be used?
Friction is the enemy of correct torque utility. Dry threads generate vital friction, skewing the readings of the torque wrench and leading to inaccurate clamping pressure. Lubricating the threads reduces friction, permitting the torque wrench to ship the exact pressure required. The producer’s service handbook specifies the suitable lubricant; deviating from this advice is ill-advised. A lightweight coating of fresh engine oil or a specialised thread lubricant is often adequate to make sure easy and correct tightening. As with the opposite torque parts, head bolt torque specs chinese language 125cc atv engine is crucial.
These often requested questions underscore a basic fact: attaining optimum engine efficiency and longevity hinges on meticulous adherence to the proper head bolt torque specs. This requires data, precision, and a deep respect for the engineering ideas that govern these small, but highly effective, engines.
Shifting ahead, the dialogue will discover widespread troubleshooting strategies for figuring out and resolving points associated to improper torque utility.
Important Steerage
The next steerage, born from hard-won expertise and solemn reflection, goals to light up the trail in direction of correctly securing these engines utilizing acceptable head bolt torque specs. These should not merely solutions, however classes realized from the echoes of mechanical failures, whispers of seized pistons, and the somber silence of engines silenced prematurely.
Tip 1: Seek the advice of the Oracle: The Producer’s Service Handbook. This seemingly mundane doc holds the secrets and techniques, the exact sequence of steps and values essential to awaken the engine. Ignore it at your peril, for generic values are siren songs that lead solely to mechanical shipwreck. The producer’s service handbook has the pinnacle bolt torque specs chinese language 125cc atv engine. It should be consulted.
Tip 2: Embrace Persistence: Divide and Conquer. The tightening course of is just not a race; it’s a deliberate dance. Apply the torque in phases, step by step growing to the ultimate worth. This enables the pinnacle gasket to compress evenly, minimizing the chance of distortion and guaranteeing a gas-tight seal. A rushed tightening is a recipe for catastrophe; haste makes waste, particularly within the delicate world of inner combustion.
Tip 3: Really feel is a Liar: Belief the Wrench, Calibrate Religiously. The human hand, nonetheless skilled, is an unreliable instrument. A torque wrench, correctly calibrated, is the one arbiter of fact. Guarantee it’s calibrated commonly, for a wrench that lies is extra harmful than no wrench in any respect. Its very purpose for current is to offer an exacting head bolt torque specs chinese language 125cc atv engine.
Tip 4: The Threads Converse: Heed Their Situation. The bolts, silent witnesses to the engine’s historical past, bear the scars of their labor. Stretched, corroded, or broken threads are an invite to failure. Discard them with out sentiment, for his or her weak spot will undermine all the endeavor. All the time examine and, when unsure, substitute.
Tip 5: Lubrication is Key: A Mild Contact, the Proper Method. Friction is the enemy, a pressure that distorts the interpretation of torque into clamping pressure. A lightweight coating of the proper lubricant, as specified by the producer, ensures a easy and correct tightening course of. Use it sparingly, for an excessive amount of will be as detrimental as too little. By no means carry out the pinnacle bolt torque specs chinese language 125cc atv engine with out lubrication.
Tip 6: The Sequence Issues: Comply with the Sample, Keep away from Distortion. The tightening sequence, usually a spiral sample emanating from the middle, is just not arbitrary. It’s a fastidiously engineered technique to distribute clamping pressure evenly throughout the cylinder head. Deviate from it, and the engine will punish your negligence. The sequence needs to be fastidiously adopted for head bolt torque specs chinese language 125cc atv engine.
Tip 7: Hearken to the Engine: Put up-Tightening Vigilance. After the tightening course of, take heed to the engine. A easy, constant idle is an indication of success. Uncommon noises, leaks, or overheating are warnings that one thing is amiss. Vigilance is the worth of mechanical reliability.
The following pointers should not mere directions; they’re the distilled knowledge of numerous hours spent wrestling with these engines. Heed them, and chances are you’ll keep away from the pitfalls which have claimed so many others.
Having explored the basic steps, the ultimate part will present a concluding assertion.
The Silent Guardians
The journey via the intricacies of correct engine upkeep, notably regarding head bolt torque specs chinese language 125cc atv engine, has been a path fraught with peril, but illuminated by the promise of reliability. Every aspect the exact torque worth, the sacred tightening sequence, the vigilant inspection of bolt situation, the even handed lubrication, and the unwavering accuracy of a calibrated torque wrench represents a vital safeguard towards mechanical misfortune. The consequence of neglecting any considered one of these parts reverberates via all the engine, resulting in diminished efficiency, untimely put on, and, in the end, catastrophic failure. This isn’t merely a technical train; it’s an act of mechanical stewardship, a recognition of the inherent fragility and the latent energy contained inside these small engines.
Think about the numerous untold tales of engines silenced prematurely, victims of neglect, indifference, or misinformation. These mechanical ghosts function stark reminders of the significance of diligence, precision, and a profound respect for the engineered parameters that govern the engine’s operate. The decision to motion is evident: strategy every engine reassembly with a reverence for element, a dedication to accuracy, and a unwavering adherence to the producer’s specs. In doing so, one not solely prolongs the lifetime of the machine, but additionally honors the engineering ingenuity that introduced it to life. Let future engines not turn out to be cautionary tales, however relatively, testaments to the enduring energy of data, talent, and a steadfast dedication to doing issues proper. When rebuilding an engine, it is extra than simply placing elements collectively. It is respecting the pinnacle bolt torque specs chinese language 125cc atv engine.
