Ezgo Kymco EX1 150cc EFI Engine

[Michael Eddie]

I'll include the wiring diagram here to kickstart this thread. Check back regularly for updates as we gather more information on the all new Ezgo Kymco EX1 150cc EFI Engine and continue to expand this thread.

Ezgo Valor EX1 TXT EFI 19, 20, 21, 22, 23, 24 (Gas) Wiring Diagram

Looking forward to sharing more insights with you soon!

Table of contents:

Post #1: Introduction
Post #2: Ezgo Gas Engine Types
Post #3: From Moped to Golf Cart
Post #4: Drive Belt & Engine/Trans/Axle Pairing
Post #5: Starter vs Stator
Post #6: The Brains Behind the Engine
Post #7: Consumer Reviews

[Michael Eddie]

Ezgo Gas Engine Types

Refer to this chart to determine whether you have the all new Kymco EX1 150cc EFI engine. Different engine types require specific maintenance procedures and all have their unique quirks. Here, we'll be discussing the Kymco EX1.

[Michael Eddie]

From Moped to Golf Cart

The all new EZGO Kymco EX1 engine draws its inspiration from the GY6 platform, which is renowned for its four stroke single cylinder engine design in a near horizontal orientation.

Originating in Asia, the GY6 engine has evolved into a widely adopted technology. Kymco, recognized for producing Honda clones like the Pulsar CB125 to Honda standards, played a significant role in refining the GY6 platform with Ezgo.

Under Honda's guidance, Kymco modified the Honda KCW125, also known as the "Spacy," into the GY6 standard model, which saw emulation and minor modifications by various Chinese manufacturers in other applications over the years. The GY6 engine gained popularity, especially in the southern coastal regions of China, after being imported from Taiwan by multiple manufacturers and traders.

The all new EZGO Kymco EX1 engine features a chain driven overhead camshaft with a crossflow hemi cylinder head. Fuel metering is achieved through an EFI system, typically a Keihin CVK clone or similar variant. Ignition is managed by capacitor discharge ignition (CDI) with a magnetic trigger located on the flywheel, allowing ignition firing on both the compression and exhaust strokes, also known as a "wasted spark" ignition. An integrated magneto provides power to the CDI system, while also rectifying and regulating AC power to 12V DC for chassis accessories and battery charging.

We've got it out on the bench for a thorough examination. From the top down view in the first picture, you can see the engine's layout, including the cylinder head and intake manifold, giving us a good overall perspective.

The engine incorporates a centrifugally controlled continuously variable transmission (CVT) with a rubber belt, sometimes referred to as a VDP. At the rear, a centrifugal clutch connects the transmission to a simple gear reduction unit. Notably, there is a drive clutch on the crankshaft between the CVT.

Engagement occurs via a driven clutch at the rear pulley, akin to scooter models like Vespa and Honda Camino/Hobbit. These detailed images provide insight into the engine's various components and can be used to help guide diagnostic and repair efforts.

While I appreciate the innovative approach EZGO has taken with the Kymco EX1 platform, I must admit that I have reservations about its long term durability and reliability. Traditionally, EZGO has relied on robust remote belt driven starter/generators for their engines, providing a tried and tested solution for starting reliability. The shift to integrating a stator with a start feature represents a departure from this established approach and introduces a new Taiwanese technology into the mix. While this innovation is intriguing, only time will tell how well it holds up, especially when subjected to the demands of real world usage and potential modifications that users may make, which could place additional strain on the power system. As such, while I'm open to embracing new technologies, I remain cautious and will be keen to see how this new system performs over time. More on this later.

Our discussion is ongoing, and we're actively exploring various aspects of this engine's design. We've taken a close look at some of its components, assessing overall health and identifying areas of concern. We're not done just yet. Be sure to check back soon on this fascinating discussion for further updates as we uncover more!

[Michael Eddie]

Drive Belt & Engine/Transmission/Axle Pairing

The diagram provided showcases how the drive belt is positioned on the EZGO EX1 engine. As you can see, the belt wraps around the pulleys on the engine which basically transmits power from the engine to the transmission/axle assembly. In the second half of the picture, you'll notice how the engine mounts to the transmission/axle assembly. This setup demonstrates how the engine's power is transferred.

Pro tip: If you take a close look, you'll spot an extra filter in the setup called the CVT filter. This filter is important for the Continuously Variable Transmission (CVT) system. It serves a vital purpose: providing clean air to the clutch system. When it gets clogged, it's like putting a wrench in the works, it can lead to overheating and potentially damage the enclosed clutch components. Keep an eye on it every 125 hours and clean it as needed.

The all new EZGO Kymco EX1 engine is air cooled, which means it doesn't rely on any liquid coolant system like typical car engines do. Instead, it uses airflow to dissipate heat and keep things running cool. The primary cooling mechanism is the flywheel fan, positioned on the engine's flywheel. We'll demonstrate this in detail later on. For now, there's a clutch fan showcased in the pic that assists in this process. It engages with the engine, increasing airflow and further cooling the engine and clutch components. Together, these fans work to regulate the engine's temperature and prevent overheating.

[Michael Eddie]

Starter vs Stator

Traditionally, EZGO has relied on a belt driven starter/generator. This item serves a dual purpose, both starting the engine and generating power for accessories. Its external design, located outside the engine, has made maintenance and replacement relatively straightforward. Over the years, this design has become familiar to technicians and golf cart owners, offering a sense of reliability and dependability.

Despite its advantages, the belt driven starter/generator is not without some drawbacks. One significant issue is belt wear. Over time, the belt can deteriorate, necessitating replacement and potentially leading to downtime for the cart. Additionally, the belt drive mechanism introduces energy losses, reducing overall efficiency. Furthermore, its external location exposes it to potential damage from debris or environmental factors, posing a risk to its reliability.

The all new EZGO Kymco EX1 engine features an internal stator that also cranks to start the engine, representing a departure from traditional designs. The integration of the stator directly into the engine offers several benefits. Firstly, it simplifies the design, reducing complexity and potential points of failure. Additionally, without the need for a belt drive, energy losses are minimized, resulting in improved overall efficiency. Moreover, the compact internal design not only saves space but also reduces the risk of external damage.

However, this innovative approach also presents some challenges. While effective for starting the engine, its unknown how limited its functionality might be compared to the belt driven starter/generator. Moreover, integrating the stator into the engine requires precise engineering, making repairs or replacements potentially more challenging. Furthermore, the introduction of new technology may necessitate a learning curve for users and technicians, requiring additional training or support for smooth operation. The incorporation of an internal stator in the EZGO Kymco EX1 powertrain represents a rare and novel technological advancement. EZGO and Kymco collaborated closely to develop this feature exclusively for the EX1 powertrain, marking a significant departure from traditional GY6 design.

So how does this innovative stator work?

As you can see in the attached images, the stator is integrated directly into the engine, eliminating the need for an external starter/generator. (Highlighted in red, also visible in item number 27 in attached 'ex1-break-down.pdf'). When the engine needs to be cranked, the stator engages with the crankshaft to initiate the engine's rotation, thus kickstarting the ignition process. During operation, it's normal for the stator to generate heat, especially when cranking the engine or under heavy loads. This heat generation is a natural byproduct of the electrical and mechanical processes involved in powering the engine. However, excessive heat buildup can accelerate wear and tear over time. Components like the stator coils and wiring may degrade faster under sustained high temperatures, potentially leading to premature failure.

Additionally, wiring within the stator assembly is susceptible to heat related insulation breakdown or solder joint failure. Over time, these cumulative effects of excessive heat can significantly impact the stator's reliability and longevity, potentially leading to unexpected failures and costly repairs depending on its long term quality.

Upon examination, the most striking observation is the stark contrast in size between the traditional starter/generator and the innovative new stator. Indeed, the traditional starter/generator appears substantial and bulky in comparison to the sleek and compact design of the new stator. The stator's performance under real world conditions remains untested and uncertain. While initial impressions may be favorable due to its compact size and streamlined integration, questions linger about its ability to withstand the rigors of prolonged use and potential stresses associated if upgrading carts with enhanced power demands. While the compact size and innovative design of the stator are commendable, reservations remain regarding its long run durability and performance, especially in scenarios involving elevated power requirements.

Stay tuned for the next update, where we'll journey into the brain technology that drives the EX1 engine. Then, brace yourselves for the exciting moment you've all been waiting for: Firsthand experiences, problems and honest feedback from hands on encounters with the EX1. From common problems reported since its debut to candid critiques, we're offering a window into the true performance and reliability of this groundbreaking engine. We'll also dive deep into common challenges faced and triumphs celebrated, providing invaluable insights for current and prospective owners. You don't wanna miss this!

[Michael Eddie]

The Brains Behind the Engine

Let's dive into the intricacies of the all new EZGO Kymco EX1 engine and its electronic control unit (ECU) and Integrated Starter Generator (ISG) modules. The ECU and ISG modules are engineered to work specifically with the EX1 engine. The ECU serves as the brain of the engine, orchestrating the operation of various sensors and components from the fuel injector to the key switch. It continuously monitors engine parameters and adjusts fuel delivery for smooth operation. Similarly, the ISG module plays a role in controlling the starter generator system, managing power delivery between the engine, battery, and electrical system.

However, despite their sophisticated software architecture, the physical placement of these modules raises legitimate concerns. (Images attached below). Mounted directly to the engine, both the ECU and ISG modules are exposed to increased heat and vibration which can potentially compromise their reliability and longevity. Now, speaking of heat and vibration, have you ever tried golfing on a volcano? Okay, maybe not quite that extreme, but, imagine the thrill of teeing off while feeling the earth rumble beneath your feet! Thankfully the Valor's sturdy construction creates a smooth ride, even on some of the most adventurous golf courses. But, lets get back to the topic at hand.

Vibration, caused by engine and terrain, can lead to loosening of various wire harness connections, potentially resulting in erratic behavior or complete shutdown of the cart. Heat, on the other hand, poses a different set of challenges. Excessive heat can degrade electronic modules causing them to malfunction or fail prematurely. Heat can also lead to thermal expansion and contraction, further stressing delicate circuitry and solder joints.

Recognizing these potential issues, EZGO has recently taken proactive steps to address them. As of 5/10/2024, shopezgo.com has been advertising the ISG as "A new, more reliable ISG controller, with a larger heat sink and improved sealing & potting around the connectors." By issuing updates to the physical design of the ISG unit, such as increased heat sinks for better cooling, EZGO aims to enhance its original design. However, the placement of these modules directly above the engine remains a concern. Heat generated by the engine can easily penetrate, exacerbating heat-related issues and potentially compromising performance.

In the event of a complete golf cart shutdown or glitch, a simple reset of the computer system may be all that's needed to restore functionality. By locating the main 10A fuse near the battery, removing it for fifteen seconds, and then replacing it, you can effectively reset the ECU and ISG modules, potentially resolving computer blips without the need for more extensive troubleshooting or repairs. Shout out to benthere for mentioning this fix in this thread.

So, what can owners of EZGO EX1 golf carts do to mitigate risks? Checking that all connectors are tight, clean, and properly seated can help. Loose connections are a known issue and can exacerbate vibration related issues and compromise electrical conductivity. Additionally, performing regular maintenance checks and inspections including visual inspection of the modules for signs of heat damage or vibration induced wear, can help identify potential issues before they escalate.

But what if you want to mitigate these risks right now? Several proactive measures can be considered. Firstly, relocating the modules to a cooler location, if feasible within the existing wiring harness constraints, could potentially improve their longevity. By moving the modules away from direct exposure to engine heat, the risk of heat related issues can be mitigated in a variety of operating conditions. Installing a heat shield between the engine and the modules can provide an extra layer of protection against heat transfer, further safeguarding sensitive electronics from thermal stress and degradation.

Additionally, mounting the ECU and ISG modules to the frame rather than directly to the engine could help minimize the effects of fine vibrations on their operation. Engine vibrations, while inevitable during operation, can be dampened more effectively when the modules are mounted to a sturdy frame structure. This reduces the risk of internal component damage due to vibration induced stress.

Feel free to check out the attached Ezgo EX1 Engine Service Manual