YAMAHA 1T9-15111-00-00 Crankcase Set Left Right Engine Crank

( Manufacturer Part Number: 1T9-15111-00-00 ), ( Part Type: Engine Crank Case ), ( Placement On Vehicle: Left ), ( Country Of Origin: Japan )

Review YAMAHA Crankcase Set Left Right Engine Crank Case fits DT100 MX100 RT100

The **Yamaha 1T9-15111-00-00 DT100/MX100/RT100 Crankcase Set (Left & Right)** is a precision-engineered, high-performance replacement component designed exclusively for Yamaha s iconic 125cc air-cooled single-cylinder engines, found in the legendary DT100 dual-sport, MX100 motocross bike, and RT100 adventure-touring motorcycle. This meticulously crafted crankcase set features a robust, cast-aluminum construction, ensuring durability and resistance to the rigors of off-road use, high-speed riding, or extended touring. The left and right crankcase halves are engineered to fit seamlessly with Yamaha s original crankshaft, connecting rod, and piston assembly, maintaining optimal power delivery, smooth operation, and long-term reliability. The crankcase set includes precision-machined oil passages and sealing surfaces, guaranteeing proper lubrication and minimizing internal friction for extended engine life. Whether you're restoring a classic Yamaha to its original glory or upgrading an older model for enhanced performance, this crankcase set is built to meet the demanding standards of both performance enthusiasts and mechanics seeking OEM-level quality. Its compatibility with the DT100 s rugged off-road design, the MX100 s high-revving motocross capabilities, and the RT100 s touring endurance makes it a versatile choice for riders who demand both performance and longevity from their engines. With its tight tolerances and Yamaha s reputation for engineering excellence, this crankcase set is an essential upgrade for anyone looking to preserve or revitalize the mechanical integrity of their bike s powerplant.

### **Pros and Cons of buying a Yamaha 1T9-15111-00-00 DT100/MX100/RT100 Crankcase Set (Left & Right Engine Crank)**

1. **Direct OEM Fitment** This is a genuine Yamaha crankcase set designed specifically for the DT100, MX100, and RT100 engines. It ensures proper alignment, sealing, and performance without modifications.

2. **High-Quality Materials** Yamaha uses durable aluminum alloys and precision machining, which improves engine longevity and reliability compared to aftermarket knockoffs.

3. **Complete Set** The package includes both the left and right crankcases, eliminating the need for separate purchases and ensuring balanced installation.

4. **Enhanced Engine Protection** A fresh crankcase set can help prevent oil leaks, reduce internal wear, and improve cooling efficiency, especially if the original casing was damaged or worn.

5. **Compatibility with Upgrades** If you plan to modify your engine (e.g., porting, cylinder head work, or performance tuning), a new crankcase provides a clean base for these upgrades.

6. **Warranty Coverage** Purchasing directly from Yamaha or an authorized dealer may include warranty protection, offering peace of mind against manufacturing defects.

7. **Improved Resale Value** A well-maintained engine with original or high-quality parts retains better resale value compared to one with neglected or mismatched components.

8. **Reduced Risk of Failure** If the original crankcase was cracked, warped, or leaking, replacing it prevents catastrophic engine failure, which can be costly to repair.

1. **High Cost** Genuine Yamaha parts are premium-priced, making this a significant investment compared to aftermarket alternatives, which may offer similar performance at a lower cost.

2. **Installation Complexity** Replacing crankcases requires disassembling the engine, removing the cylinder, and carefully aligning the new parts. This is a labor-intensive job best left to experienced mechanics unless you have mechanical expertise.

3. **Potential for Overkill** If the original crankcase is still structurally sound (no cracks, leaks, or excessive wear), replacing it may be unnecessary, making the upgrade a costly precaution.

4. **Limited Availability** Depending on your location, genuine Yamaha parts may not be readily available at local dealers, requiring online purchases or shipping delays.

5. **Time-Consuming** The installation process can take several hours, depending on your skill level and the condition of surrounding components (e.g., gaskets, seals, or bearings that may need replacement).

6. **No Performance Gains** Unlike performance upgrades (e.g., bigger carburetors, exhaust systems, or high-compression pistons), a crankcase replacement does not improve horsepower or throttle response it primarily addresses structural integrity and reliability.

7. **Risk of Damage During Removal** If the engine is not properly supported or if components are stripped during disassembly, additional repairs may be needed, increasing costs.

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The Yamaha **1T9-15111-00-00 crankcase set** is a high-quality, OEM-replacement part that is ideal for owners who prioritize reliability, longevity, and peace of mind. It is particularly justified if the original crankcase is damaged, leaking, or showing signs of wear. However, the cost and labor involved make it less appealing for routine maintenance or cosmetic upgrades.

- **Restoring a damaged engine** (e.g., after an accident or oil leak).

- **Preparing the engine for major modifications** (e.g., porting, cylinder work).

- **Ensuring long-term durability** if the bike is used aggressively or in harsh conditions.

If your crankcase is still in good condition, an aftermarket alternative (e.g., from reputable brands like **Kawasaki, Honda, or high-quality third-party manufacturers**) may offer a more cost-effective solution without sacrificing quality.

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- Your original crankcase is cracked, warped, or leaking.

- You are undertaking a full engine rebuild or major modification.

- You value OEM quality and warranty coverage.

- You have the mechanical skills or access to a trusted mechanic for installation.

- The original crankcase is still functional but worn (e.g., minor surface corrosion).

- You are on a tight budget and can find a high-quality aftermarket set with good reviews.

- You are not planning engine modifications and only need a replacement for cosmetic or minor reliability concerns.

For best results, pair this purchase with a **full engine service**, including new gaskets, seals, and bearings, to ensure optimal performance. Always verify compatibility with your specific model year and consult a Yamaha technician if unsure.

Details:

DT100 1977 - 1983. RT100 1990 - 2000. MX100 1979 - 1983. THERE IS 1 SMALL BROKEN PIECE ON LEFT CASE BELOW CLUTCH ARM.

part #: 1t9151110000 prices

• $119.00-$585.00

specifications cyclevintagee:

• for models: Dt100, Mx100, Rt100
• for makes: Yamaha
• mpn: 1t9-15111-00-00
• part type: Engine Crank Case
• placement on vehicle: Left
• country of origin: Japan

payments cyclevintagee:

• other
• credit card: Discover
• wallet: Paypal

offer cyclevintagee:

• options: Ship-to-home
• started: February 17, 2026
• sold: 0
• availability: In Stock
• quantity: 1

returns cyclevintagee:

• policy: No Returns

shipping cyclevintagee:

• carrier: USPS
• type: Fixed
• transit: 3-8 Days
• class: Standard
• service: USPS Ground Advantage
• cost: $17.00

general cyclevintagee:

• condition: Used
• Parts Accessories > Motorcycle Scooter Parts Accessories > Other Motorcycle Scooter Parts Accessories

seller cyclevintagee:

• city: Lancaster, Pennsylvania
• # reviews: 2400
• rating: 100.0%

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