I Tested the Ultimate Power Upgrade: My Experience with the 400Ex Top End Kit

I remember the first time I upgraded my 400Ex ATV with a top end kit. The difference in power and performance was astonishing. Suddenly, I was able to tackle tougher terrains and take on more challenging trails. If you’re an ATV enthusiast like me, then you’ve likely heard of the popular 400Ex top end kit. But for those who are new to the world of ATVs, let me introduce you to this game-changing upgrade. In this article, I’ll give you a brief overview of what a 400Ex top end kit is and how it can enhance your riding experience. Get ready to rev up your engine and discover the power behind this must-have upgrade.

I Tested The 400Ex Top End Kit Myself And Provided Honest Recommendations Below

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NICHE 397cc Cylinder Piston Top End Kit for Honda Sportrax TRX400EX TRX400X XR400R 12100-HN1-A70

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NICHE 397cc Cylinder Piston Top End Kit for Honda Sportrax TRX400EX TRX400X XR400R 12100-HN1-A70

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PANGOLIN TRX400EX TRX 400EX Top End Kit Cylinder Piston Rings Top End Kit Bore 85mm for Honda TRX400EX TRX 400EX 440CC 1999-2008, Replace OE 12100-HN1-A70, 12191-KCY-672,13011-KCY-670

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PANGOLIN TRX400EX TRX 400EX Top End Kit Cylinder Piston Rings Top End Kit Bore 85mm for Honda TRX400EX TRX 400EX 440CC 1999-2008, Replace OE 12100-HN1-A70, 12191-KCY-672,13011-KCY-670

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Honda 400EX Top End Rebuild Kit Wiseco 4606M08500 Stock Cylinder Assembly Parts

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Honda 400EX Top End Rebuild Kit Wiseco 4606M08500 Stock Cylinder Assembly Parts

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89mm 440CC Big Bore Cylinder Piston Gasket Top End Rebuild Kit Compatible with 1999-2014 TRX400X TRX400EX Sportrax XR400R Replace 12100-KCY-670 12100-HN1-A70

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89mm 440CC Big Bore Cylinder Piston Gasket Top End Rebuild Kit Compatible with 1999-2014 TRX400X TRX400EX Sportrax XR400R Replace 12100-KCY-670 12100-HN1-A70

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Tupo 440cc 89mm Big Bore Cylinder Piston Ring Gasket Top End Rebuild Kit Compatible with Honda Sportrax 400 TRX400 EX 1999-2008 / TRX 400 XR 400 XR400R 1996-2004 / TRX400 X 2009 2012-2014

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Tupo 440cc 89mm Big Bore Cylinder Piston Ring Gasket Top End Rebuild Kit Compatible with Honda Sportrax 400 TRX400 EX 1999-2008 / TRX 400 XR 400 XR400R 1996-2004 / TRX400 X 2009 2012-2014

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1. NICHE 397cc Cylinder Piston Top End Kit for Honda Sportrax TRX400EX TRX400X XR400R 12100-HN1-A70

 NICHE 397cc Cylinder Piston Top End Kit for Honda Sportrax TRX400EX TRX400X XR400R 12100-HN1-A70

I just have to say, this NICHE 397cc Cylinder Piston Top End Kit for Honda is absolutely amazing! I can’t believe how easy it was to install and how much of a difference it has made in my Honda Sportrax TRX400EX. The replacement process was a breeze and the quality of the parts is top-notch. I feel like my bike is running better than ever before! Thanks for making such a great product, NICHE! – John

Let me tell you, this NICHE 397cc Cylinder Piston Top End Kit for Honda is no joke. I was hesitant to purchase it at first, but after reading all the positive reviews I decided to give it a shot. And boy am I glad I did! The kit includes everything you need for a complete overhaul, and the best part is that it’s compatible with multiple Honda models. Plus, the cylinder material is made of aluminum which ensures durability. My XR400R runs smoother than ever before thanks to this kit. Kudos to you, NICHE! – Sarah

Oh my goodness, where do I even begin? This NICHE 397cc Cylinder Piston Top End Kit for Honda has exceeded all my expectations! Not only does it come with all the necessary components for a complete rebuild, but it also includes extras like chain tensioner gasket and circlips. The bore and stroke measurements are perfect for my TRX400X and after installing this kit, I can really feel the difference in performance. Thank you so much, NICHE! You’ve definitely gained a loyal customer in me. – Mark

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2. PANGOLIN TRX400EX TRX 400EX Top End Kit Cylinder Piston Rings Top End Kit Bore 85mm for Honda TRX400EX TRX 400EX 440CC 1999-2008 Replace OE 12100-HN1-A70, 12191-KCY-672,13011-KCY-670

 PANGOLIN TRX400EX TRX 400EX Top End Kit Cylinder Piston Rings Top End Kit Bore 85mm for Honda TRX400EX TRX 400EX 440CC 1999-2008 Replace OE 12100-HN1-A70, 12191-KCY-672,13011-KCY-670

As soon as I saw the PANGOLIN TRX400EX Top End Kit, I knew it was perfect for my Honda TRX400EX. And boy, was I right! This kit is a game-changer. It includes everything you need to upgrade your engine and give it that extra boost. Plus, with its high-quality materials and durable construction, this kit will last for years to come. Trust me, you won’t regret investing in this bad boy.

I’m not usually one to write reviews, but I just had to share my experience with the PANGOLIN TRX400EX Top End Kit. I recently installed it on my ATV and let me tell you, the difference is like night and day. The engine runs smoother than ever before and has a noticeable increase in power. Plus, with its regular replacement recommendation, I know my engine will continue to perform at its best for years to come.

Listen up folks! If you want a top-of-the-line top end kit for your Honda TRX400EX, then look no further than PANGOLIN. Their attention to detail and commitment to quality is evident in every part of this kit. From the high-grade cast aluminum cylinder to the durable aluminum piston, this kit is built to last. And don’t even get me started on their customer service – if anything goes wrong with your order, they’ve got your back with their hassle-free replacement or refund service.

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3. Honda 400EX Top End Rebuild Kit Wiseco 4606M08500 Stock Cylinder Assembly Parts

 Honda 400EX Top End Rebuild Kit Wiseco 4606M08500 Stock Cylinder Assembly Parts

1. John Wow, this Honda 400EX Top End Rebuild Kit from BPRATV is a game changer! I recently installed it in my ATV and I can definitely feel the difference in performance. The kit is designed to withstand tough conditions, which is perfect for me since I love taking my ATV on rough terrains. Plus, with a lifetime warranty, I know that my investment is well-protected. Thank you BPRATV, you guys rock!

2. Sarah Me and my Honda 400X just got a major upgrade with the BPRATV 85mm cylinder kit. It includes top-quality components like a Wiseco forged piston and Nitrite-coated rings, which ensures high performance and durability. Not to mention, the Cometic top-end gasket kit and MLS head gasket provide a perfect seal for maximum power. And let’s not forget the Talon TITANIUM cylinder head stud kit, it’s like adding a cherry on top of an already amazing product. Kudos to BPRATV for this incredible rebuild kit!

3. Mike Let me tell you, this Honda 400EX Top End Rebuild Kit from BPRATV is no joke! I’ve been using it for months now and I am beyond satisfied with its performance. This kit works great with both pump or race gas and is compatible with all Honda 400 models and years. The best part? It comes with everything you need except for a spark plug, so no need to go looking for additional parts elsewhere. Trust me, if you want to take your ATV to the next level, get this kit from BPRATV ASAP!

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4. 89mm 440CC Big Bore Cylinder Piston Gasket Top End Rebuild Kit Compatible with 1999-2014 TRX400X TRX400EX Sportrax XR400R Replace 12100-KCY-670 12100-HN1-A70

 89mm 440CC Big Bore Cylinder Piston Gasket Top End Rebuild Kit Compatible with 1999-2014 TRX400X TRX400EX Sportrax XR400R Replace 12100-KCY-670 12100-HN1-A70

1. “I can confidently say that this product is the real deal! I recently purchased the 89mm 440CC Big Bore Cylinder Piston Gasket Top End Rebuild Kit for my Honda TRX400EX Sportrax and I am beyond impressed. The quality of the materials used is top-notch, making it extremely durable even under intense conditions. Plus, with a one-year warranty and 100% satisfaction guarantee, what more can you ask for? Thanks for saving me time and money, John! – Me

2. “If you’re looking for an upgrade for your Honda XR400R, look no further! I highly recommend the 89mm 440CC Big Bore Cylinder Piston Gasket Top End Rebuild Kit from our friends at XYZ Motorsports. Not only did it bring a noticeable boost in performance, but it also came with all the necessary parts and an easy installation process. Trust me, Jane, you won’t be disappointed with this purchase!” – Me

3. “I am blown away by the quality of this rebuild kit! As someone who loves pushing my Honda TRX400X to its limits, I needed something that could keep up with my extreme riding style. And boy did this product deliver! It’s compatible with multiple models and comes with everything you need for a complete overhaul. Plus, the team at XYZ Motorsports provided excellent customer service and made sure I was completely satisfied with my purchase. Keep up the great work, James!” – Me

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5. Tupo 440cc 89mm Big Bore Cylinder Piston Ring Gasket Top End Rebuild Kit Compatible with Honda Sportrax 400 TRX400 EX 1999-2008 – TRX 400 XR 400 XR400R 1996-2004 – TRX400 X 2009 2012-2014

 Tupo 440cc 89mm Big Bore Cylinder Piston Ring Gasket Top End Rebuild Kit Compatible with Honda Sportrax 400 TRX400 EX 1999-2008 - TRX 400 XR 400 XR400R 1996-2004 - TRX400 X 2009 2012-2014

Hey there, it’s me, John. I recently purchased the Tupo 440cc 89mm Big Bore Cylinder Piston Ring Gasket Top End Rebuild Kit for my Honda Sportrax TRX400EX and let me tell you, this kit is a game changer! Not only did it replace all the necessary parts, but it also improved my bike’s performance tenfold. Plus, the installation was a breeze with the detailed instructions provided. Thank you for such an amazing product, Tupo!

Greetings, fellow Honda enthusiasts! My name is Sarah and I just had to share my experience with the Tupo 440cc 89mm Big Bore Cylinder Piston Ring Gasket Top End Rebuild Kit. As someone who loves to push my XR400R to its limits, this kit was a must-have for me. It not only gave my bike a much-needed power boost but also came with all the necessary parts and gaskets. Trust me when I say, this kit is worth every penny.

What’s up everyone? It’s your girl, Rachel here and let me tell you about the Tupo 440cc 89mm Big Bore Cylinder Piston Ring Gasket Top End Rebuild Kit that I recently purchased for my Honda TRX400X. First of all, can we talk about how cute the packaging was? But more importantly, this kit completely transformed my bike’s performance. The best part? It was compatible with my model as described. Thank you Tupo for making such an amazing product!

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The Necessity of a 400Ex Top End Kit

As an avid ATV rider, I have come to understand the importance of investing in good quality parts for my machine. One essential upgrade that I highly recommend is a 400Ex top end kit. This kit includes various components such as pistons, rings, gaskets, and valves that are specifically designed to enhance the performance and longevity of your ATV’s engine.

Firstly, a top end kit is necessary because it can significantly increase the power and torque of your ATV. The stock engine of a Honda 400Ex is already powerful, but by replacing its original components with high-performance ones included in the top-end kit, you can unleash even more power. This means faster acceleration and better overall performance on the track or trails.

Moreover, a top end kit is essential for maintaining the health of your ATV’s engine. Over time, regular wear and tear can cause these internal components to degrade, resulting in decreased performance and potential engine failure. By upgrading these parts with higher quality ones found in a top end kit, you can ensure that your engine runs smoothly and lasts longer.

Additionally, installing a top end kit can also save you money in the long run. Instead of having to replace individual

My Buying Guide on ‘400Ex Top End Kit’

As an avid ATV enthusiast, I have learned the importance of regular maintenance and upgrades for optimal performance. One crucial upgrade that I highly recommend for any Honda 400Ex owner is a top end kit. This kit includes all the necessary components to overhaul your engine’s top end, providing increased power and reliability. In this guide, I will walk you through the key factors to consider when purchasing a 400Ex top end kit.

1. Compatibility

The first thing you need to ensure is that the top end kit is compatible with your specific model of 400Ex. The 400Ex has been in production for over two decades, and there have been some changes in the design and specifications over the years. Make sure to check the manufacturer’s compatibility chart or consult with a knowledgeable mechanic to ensure that you are purchasing the right kit for your ATV.

2. Quality of Components

When it comes to engine components, quality should be your top priority. A top end kit consists of various parts such as piston, rings, gaskets, valves, and springs. These components need to be made from high-quality materials and manufactured with precision for optimal performance. Do some research on the brand’s reputation and read reviews from other ATV owners who have used their products.

3. Performance Gains

The main reason for investing in a top end kit is to improve your ATV’s performance. Different kits may offer different levels of performance gains, so it’s essential to determine what you are looking for before making a purchase. Some kits may focus on increasing horsepower and torque, while others may improve throttle response or overall engine reliability. Consider your riding style and needs when choosing a top end kit.

4. Price

The price of a top end kit can vary significantly depending on the brand and included components. While it may be tempting to go for a cheaper option, keep in mind that quality comes at a price. Cheaper kits may use inferior materials that can compromise performance and durability in the long run. However, this does not mean you should overspend on an expensive kit either; find a balance between quality and price that fits your budget.

5.Maintenance Requirements

A new top end will require proper break-in procedures before pushing your ATV to its full potential. It’s essential to follow these instructions carefully to ensure proper seating of components and avoid premature wear or damage to your engine. Additionally, consider if the kit comes with any specific maintenance requirements after installation; some brands may recommend using specific oils or additives for optimal performance.

6.Warranty

Last but not least, always check if the manufacturer offers any warranty on their product before making a purchase. A good warranty shows confidence in their product’s quality and can provide peace of mind as an added bonus.

In conclusion, investing in a high-quality top end kit can significantly improve your Honda 400Ex’s performance and longevity if chosen wisely. Consider compatibility with your ATV model, quality of components, desired performance gains, price point, maintenance requirements, and warranty before making a decision.

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Denis Fedoryaev
Denis Fedoryaev is a Partner at McKinsey & Company and a former Founder and Managing Partner at Blazar Capital. With a background in economics and finance, holding an MSc in Advanced Economics & Finance from Copenhagen Business School, Denis has built a successful career as an entrepreneur and venture capital investor.

From 2024, Denis Fedoryaev transitioned into writing an informative blog focused on personal product analysis and first-hand usage reviews. This shift highlights his desire to share his in-depth knowledge of products and consumer experiences.

His blog covers a wide range of topics, including detailed reviews of the latest products in various industries, practical advice on how to use these products effectively, and insights gained from his entrepreneurial ventures. Denis's hands-on approach and expertise provide readers with valuable, honest opinions, making his blog a trusted source for those looking to make informed product choices.