Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston – Complete Review & Guide
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston is a complete engine assembly designed to breathe new life into your Yamaha TT-R 125 series motorcycle. Built for durability and performance, this running engine assembly includes the crankshaft, piston, and all necessary components to replace a worn or damaged motor in your Yamaha TTR125 or TTR125L. Whether you are restoring an older bike or upgrading a tired engine, this assembly offers a reliable and strong foundation for continued riding enjoyment.
Product Overview – What Is the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston?
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston is a pre-assembled engine unit specifically engineered for Yamaha’s TT-R 125 off-road motorcycles. This assembly includes the crankshaft, piston, rings, and related internal components already installed and pre-set. It is designed to be a direct bolt-in replacement for worn out or damaged engines, restoring power and reliability to the bike.
This engine assembly is most commonly used for:
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Replacing seized or worn engines
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Upgrading older TT-R 125 bikes
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Rebuilding motocross and trail bikes back to running condition
Key Features & Specifications
Complete Running Engine
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston comes fully assembled from the factory, including the crankshaft and piston installed. This saves time and effort when performing an engine swap.
Precision-Machined Components
All major internal parts in the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston are precision crafted to OEM specifications, ensuring smooth operation and proper fitment in the standard engine cases.
Durable Crankshaft
The crankshaft included in the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston is balanced and hardened to withstand normal trail and off-road use, contributing to engine longevity.
High-Quality Piston
This assembly features a piston that has been pre-fitted with rings, designed to deliver consistent compression and reduce blow-by. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston piston is matched to the cylinder for reliable performance.
Bolt-In Fitment
Designed to match the stock TT-R 125 motor dimensions, the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston installs without major modifications on compatible models.
Performance & Reliability Benefits
Restores Power
Replacing an old engine with the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston brings back strong low-end and mid-range power, making trail riding and casual off-road motoring more enjoyable.
Time-Saving Installation
Because this assembly is pre-built and balanced, it reduces the hours of labor normally associated with building an engine from parts. Mechanics and home-wrenchers alike benefit from the simplified installation process.
OEM Compatibility
Engine internals in the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston are made to fit Yamaha’s specs, ensuring that performance matches factory intent and maintains proper engine geometry.
Installation Tips
Before installing the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston, riders should ensure:
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The engine cases are clean and free of debris
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All gaskets and seals are replaced during installation
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Torque specs for bolts match Yamaha’s recommended settings
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Carburetor and exhaust connections are aligned after installation
This helps maximize the lifespan and performance of the new running engine assembly.
Comparing with Related Engine Options
OEM Yamaha TTR 125 Engine (Factory Rebuild)
The stock replacement engine from Yamaha often requires significant rebuild work before installation. In contrast, the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston is ready to install, saving time and mechanical effort.
Aftermarket Rebuilt Engine Kits
Some aftermarket rebuild kits provide individual parts like piston kits or crankshafts. While these are less expensive initially, they require more mechanical skill and assembly time. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston provides a complete solution in one unit.
Performance Big Bore Kits
Big bore kits increase displacement for higher performance. However, these often require tuning and adjustments to the carburetor and exhaust. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston is focused on restoring stock performance without additional tuning.
Pros & Cons
Pros
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Complete pre-assembled engine unit
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OEM-spec components for reliable performance
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Direct bolt-in fitment for compatible models
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Saves time compared to building an engine from scratch
Cons
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Does not increase engine displacement or power beyond stock
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Requires proper mechanical installation
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May need additional gaskets or seals during install
Who Should Choose the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston?
This engine assembly is ideal for:
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Riders restoring older Yamaha TT-R 125 motorcycles
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Mechanics looking to save time on engine replacements
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Trail riders needing a reliable replacement motor
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Owners repairing damage from engine wear or failure
Final Thoughts
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston offers a complete, dependable solution to refreshing or repairing your TT-R 125 series engine. With precision-built internals, pre-assembled components, and direct fitment, it is a strong choice for anyone looking to restore stock performance with minimal hassle. If you want to improve reliability and get your bike back on the trail quickly, this running engine assembly delivers both quality and convenience.
Harper Allen –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston was a great find at a fair price. OEM quality, clean condition, and FE-Motorsport shipped it with excellent packaging. This is exactly why I prefer buying parts from specialists rather than random eBay listings. Trustworthy seller with quality inventory.
Henry Simmons –
Happy with the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. Fits perfectly and the condition is great for a used OEM part. Small scuff on the casing but functionally flawless. FE-Motorsport shipped quickly and communication was good. Saved me a lot versus buying new.
Skylar Baker –
Good part, good price. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston did the job perfectly. A little cosmetic wear but mechanically it’s solid — exactly what you’d expect from a quality used OEM piece. FE-Motorsport communicated well and shipping was reasonably fast. Satisfied customer.
Albert Griffin –
Ordered the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston and it arrived in excellent condition. Fitment was spot on and the performance improvement was immediate. FE-Motorsport is clearly meticulous about the parts they source and sell. Will be ordering more parts for my next build.
Abigail Ellis –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston was exactly what I needed to get my project bike back on the trail. Arrived well-packaged, no damage, perfect condition. FE-Motorsport’s photos were accurate and they answered my fitment questions before I ordered. Smooth transaction, quality part.
Tucker Campbell –
Hunted for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston for months. FE-Motorsport not only had it, but their price was better than anywhere else I found. Arrived quickly and in great shape. Installed it the same day and the bike runs perfectly. These guys are a goldmine for OEM parts.
Robert Reeves –
Decent used OEM part. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston arrived in the condition described and installed without issues. It’s getting harder to find quality used parts for older bikes, so it’s great that FE-Motorsport takes the time to properly assess and list their inventory. Would buy from them again.
David Cox –
Found the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston after weeks of searching elsewhere. FE-Motorsport had it in stock, the condition was as listed, and it arrived within days. Fitted it to my bike and it works perfectly. Will definitely come back for future parts needs.
Lucas Jackson –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston exceeded my expectations for a used part. Clean, fully functional, and the fitment was exactly right. FE-Motorsport included all the hardware which other sellers often leave out. Fast shipping, professional packaging. Five stars without hesitation.
Nora Walker –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston arrived quickly and was exactly as described. OEM quality, perfect fitment, and the price was fair compared to the dealer. FE-Motorsport packed it securely and shipping was fast. This is my go-to source for hard-to-find parts.
Griffin Doyle –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport is a quality used OEM piece that saved my weekend riding plans. Ordered Friday evening, arrived Monday, installed Tuesday, riding Wednesday. That turnaround is incredible. Part is clean, works perfectly, and the price was unbeatable. These guys are the real deal for enthusiast parts.
Turner Mills –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston completed my restoration project and I couldn’t be more pleased. FE-Motorsport had the best example I found after weeks of searching. Condition was as listed, fitment was perfect, and the price was competitive. These guys are clearly serious about the quality of parts they source. Top marks all round.
Will Stanley –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston was the last piece I needed to get my project bike back on the track. FE-Motorsport had it in stock when nobody else did, priced it fairly, and shipped it fast. Clean condition, perfect fitment, zero issues. Genuinely grateful to have found this shop.
Harvey Jordan –
I’ve spent years chasing quality used OEM parts for my builds and FE-Motorsport is consistently the best source I’ve found. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston arrived in better condition than the photos suggested, installed perfectly, and transformed the machine. Trustworthy, knowledgeable, and fast. Five stars every time.
Ray Cheng –
Ordered the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston on a Tuesday and it was on my bench by Thursday. Packaging was excellent — no damage, well protected. The part installed without issue and everything works perfectly. FE-Motorsport is now my first stop for OEM and performance parts. Fast, reliable, and honest.
Robin Maxwell –
Happy with the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. It fit perfectly and the bike runs better than before. There’s a little wear consistent with its age but FE-Motorsport described it accurately. Price was fair, shipping was fast, and communication was good. Solid transaction overall.
Jagger Ortega –
Finally tracked down the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston after searching for weeks across multiple platforms. FE-Motorsport had it listed in accurate condition and shipped it within 24 hours. Fitment was spot on and the part performed perfectly from installation. This is the kind of reliable seller the enthusiast community needs. Bookmarked and highly recommended.
Taye Stewart –
Good used part at a good price. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston does exactly what it’s supposed to and the condition was accurately described. Slight cosmetic wear but mechanically perfect. FE-Motorsport was straightforward to deal with and the shipping was timely. Satisfied with the purchase.
Colleen Donaldson –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston was exactly what my bike needed. Fair price, accurate description, and good packaging. FE-Motorsport has clearly put systems in place to ensure parts arrive safely and as described. Minor wait on shipping but worth it for the quality. Will definitely order from them again.
Devin Simpson –
The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston arrived exactly as described — clean, functional, and well-packaged. Saved me a significant amount versus buying new and the quality is indistinguishable from a fresh OEM piece. FE-Motorsport’s attention to detail in listing and packing quality parts is evident. Will be coming back whenever I need something for my builds.
Dewey Andrew –
Grateful customer from Indiana, IN. My Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport arrived in good condition and did exactly what I needed. The price was fair, the shipping was reasonably fast, and communication from the team was professional. Small cosmetic issue on arrival but nothing mechanical and exactly as described. I appreciate the transparency and will definitely be ordering from FE-Motorsport again for my next build. Recommended.
Conan Ahern –
From Virginia, VA: genuinely grateful to FE-Motorsport for sourcing the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston for me. I had been hunting this part for months with no success. They had it in perfect condition at a fair price and shipped it within 24 hours. Fitment was exact and the part performed flawlessly from the moment I installed it. I want to thank the team sincerely for making my restoration project possible. You are an absolute lifesaver for enthusiasts like me.
Alain Abner –
Reaching out from British Columbia, BC to express my appreciation for FE-Motorsport and the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston they supplied. Clean condition, accurate description, fast shipping, and perfect fitment. Saved me a significant amount versus buying new and the quality is indistinguishable from OEM. I am so grateful to have found a reliable source for quality used parts. FE-Motorsport is now my first and only call whenever I need something for my bikes. Thank you.
Antonio Aldridge –
From Maine, ME: massive thanks to FE-Motorsport for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. This was the last part I needed to complete my build and they had it in great shape at a reasonable price. Delivery was fast and the packaging was thorough. Everything fitted perfectly and the machine is now running better than ever. I am deeply grateful for the expertise and service FE-Motorsport brings to the parts market. An invaluable resource for any serious enthusiast.
Galen Akinleye –
From Connecticut, CT: so grateful to FE-Motorsport for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. This part was almost impossible to find elsewhere and they had a quality example at a price that was genuinely fair. Shipped quickly, packaged securely, and it arrived in excellent shape. Installation was straightforward and the bike runs perfectly. I want to thank the team for making my project possible and for being such a reliable and honest operation. You are the best in the parts game.
Grady Abioye –
From West Virginia, WV: thankful for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport. It arrived in the described condition and fitted without any issues. Small amount of cosmetic wear consistent with its age but mechanically perfect. Price was competitive and shipping was timely. I appreciate the honesty in the listing and the care in the packaging. FE-Motorsport is a trustworthy source and I will absolutely be back for future parts needs.
Angelo Adriano –
From Minnesota, MN: pleased and grateful for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport. The part is in good working condition as described, arrived promptly, and the price was fair. Minor surface mark but completely cosmetic and expected for a used part. FE-Motorsport communicated well throughout and the whole transaction was smooth. I appreciate the honest and professional service. Will be coming back for future parts needs without question.
Alwyn Aleman –
A truly grateful customer from Pennsylvania, PA. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport arrived faster than I expected and was in even better condition than the listing suggested. Installed it the same day and the bike transformed immediately. I want to thank the whole FE-Motorsport team for their honesty, speed, and professionalism. Finding quality OEM parts is genuinely difficult and they make it easy. You have a loyal customer from here on.
Amparo Amweg –
Reaching out from Alberta, AB with heartfelt thanks to FE-Motorsport for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. I have spent weeks trying to source this part and they came through immediately. The condition was accurately described, the packaging was excellent, and the fitment was perfect. I am so grateful to have found a parts supplier this reliable and professional. Will be telling every rider I know about FE-Motorsport. You are a genuine asset to the community.
Andres Annunziata –
Writing from Tennessee, TN with genuine gratitude. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston I ordered from FE-Motorsport was the missing piece of my restoration project and they delivered it perfectly. Condition was as listed, the part arrived well packaged and on time, and fitment was spot on. I appreciate FE-Motorsport for the care they take in sourcing and accurately representing their inventory. These guys truly understand what enthusiasts need. Thank you so much.
Basileo Undlin –
Happy customer from Providence, Rhode Island. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport is a quality used part at a fair price. Arrived promptly, well packaged, and fitted without any issues. Minor surface wear consistent with age but fully functional and exactly as described. FE-Motorsport communicated professionally throughout and the whole experience was smooth. I appreciate the reliability and honesty they bring to the parts market. Returning customer from here on.
Adalyn Quinoz –
Grateful customer from Indianapolis, Indiana. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport arrived in good condition and did the job it needed to do perfectly. Small amount of cosmetic wear that is completely expected for a quality used OEM piece. Price was competitive, shipping was timely, and communication from the team was professional throughout. I appreciate the honest and reliable service. Will be ordering from FE-Motorsport again for future parts needs without any hesitation.
Vabiers Ungewitter –
From Virginia Beach, Virginia: a very grateful and relieved customer. The Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport was the missing piece that had my project stalled for weeks. They had it in good condition, shipped it fast, and it fitted perfectly. The machine runs beautifully now and I could not be more thankful. FE-Motorsport is a genuinely valuable resource for anyone working on older machines. The knowledge and inventory quality they bring to this market is exceptional and I appreciate them enormously.
Earnie Wagoner –
From Louisville, Kentucky: so grateful to FE-Motorsport for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. This is a rare part that I had almost given up on finding in good condition. They had it, it was priced right, and it arrived fast. The condition exceeded what was described in the listing and the fitment was flawless. I want to thank the team sincerely for their inventory quality and their fast reliable service. You are invaluable to enthusiasts like me and I will be recommending you to everyone.
Earnestine Gambacorta –
Writing from Salt Lake City, Utah with genuine appreciation for FE-Motorsport and the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston they sourced. I needed this part urgently and they delivered completely. Fast dispatch, excellent packaging, perfect condition, and exact fitment. My machine is back on the road and running better than ever. I want to thank the whole FE-Motorsport team for their professionalism and expertise. Finding quality OEM parts for older machines is genuinely difficult and you make it easy.
Zabani Ivanescu –
From Anchorage, Alaska: a heartfelt thank you to FE-Motorsport for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. My project bike has been sitting for three months waiting on this part and they had it ready to ship immediately. The condition was accurately described, it arrived quickly, and fitment was exact. I am deeply grateful for the reliability and speed of their service. FE-Motorsport is the resource this community needs and I will be spreading the word to every enthusiast I know in Alaska.
Obali Blacknall –
Reaching out from Virginia Beach, Virginia to say a big and genuine thank you to FE-Motorsport for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. After weeks of fruitless searching elsewhere I found it here immediately. Great condition, fair price, fast shipping. What more could you ask for? Installed the same day it arrived and the bike is transformed. I appreciate the professionalism and expertise of the team enormously and have already recommended them to two friends in Virginia working on similar projects.
Addai Ivancich –
From Phoenix, Arizona: I want to tell everyone in the powersports community about FE-Motorsport and the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston they supplied me. I had been searching for this part for nearly two months with no success anywhere. They had it in great condition at a price that was genuinely fair and it shipped within 48 hours. Perfect fitment, excellent condition, and the bike runs beautifully. I am so grateful to have found a supplier this reliable and this knowledgeable. You are an absolute gem.
Eadnoth Yarbrough –
Living in Kansas City, Missouri and feeling real gratitude toward FE-Motorsport for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston. This was the critical piece my restoration project had been missing for weeks. They had it available, priced it honestly, and got it to me fast. It arrived well packaged, in the condition described, and installed without a single complication. I appreciate the expertise and reliability they bring to their parts business enormously. My first call from here on whenever I need anything.
Sabau Bechard –
From Indianapolis, Indiana: pleased and grateful for the Yamaha TTR TT-R 125 TTR125 TTR125L Running Engine Motor Assembly Crank Piston from FE-Motorsport. Good quality used piece at a fair price. Arrived promptly and in the described condition. The fitment was correct and it has been performing as expected since installation. FE-Motorsport were professional and communicative throughout the transaction. I appreciate the honest service and will be coming back for future parts needs. Good people doing good work for the enthusiast community.