1. Antique, Vintage, Historic Motorcycle Parts For Sale
  2. sku: 20640365625734633
  3. YAMAHA 3R4-18101-01

YAMAHA 3R4-18101-01 Nos Shaft

fits model: Yz465, It250. make: Yamaha. year: 1980–1981.

3r4-18101-01 Yamaha Nos Oem Shift Shaft Assembly 1980 Yz465 1981 It250

( Manufacturer Part Number: 3R4-18101-01 ), ( Part Type: Shaft ), ( Unit Type: Unit ), ( Machine Type: Dual Sport Motorcycle ), ( Vintage Part: Yes ), ( Compatible Year: 1978 ), ( Country Of Origin: Japan ), ( Performance Part: No )

Review YAMAHA Nos Oem Shift Shaft Assembly fits YZ465 IT250 1980–1981

The **Yamaha 3R4-18101-01 NOS (New Old Stock) Shaft** from the early 1980s is a highly sought-after, meticulously preserved component that embodies the raw mechanical elegance of Yamaha s legendary two-stroke racing heritage. Originally designed for the **1980 YZ465** and later adapted for the **1981 IT250**, this shaft represents a critical piece of the engine s drivetrain, responsible for transmitting power from the crankshaft to the rear wheel with precision and efficiency. Crafted from high-grade steel, the shaft is forged to exacting tolerances, ensuring durability and reliability under the extreme stresses of high-revving, high-performance racing applications. Its polished, matte finish reveals subtle machining marks and the faintest traces of wear, evidence of its authentic vintage origins, while the overall condition remains pristine free from rust, bends, or signs of modification, making it a true NOS specimen. The shaft s design reflects Yamaha s engineering prowess of the era, featuring a tapered profile and balanced weight distribution to optimize power delivery and reduce vibration, a hallmark of the brand s commitment to performance. Whether integrated into a restored classic race bike or a modern project seeking authenticity, this shaft offers a tangible connection to a pivotal moment in motocross history, where Yamaha dominated the sport with its innovative and fearless engineering. For collectors, restorers, and enthusiasts, this NOS shaft is not merely a functional part but a piece of mechanical art, embodying the spirit of an era when speed and craftsmanship were inseparable.

### **Pros and Cons of Buying a 1980 Yamaha 3R4-18101-01 (NOS Shaft) and a 1981 YZ465/1981 IT250**

#### **Yamaha 3R4-18101-01 (1980, NOS Shaft)**

The **3R4-18101-01** is a classic **Yamaha 3R4** carburetor, known for its reliability and performance in vintage Yamaha engines. Since it is listed as **"NOS shaft"** (new old stock or near-original condition), it retains much of its original integrity.

**Pros:**

1. **Authentic and Rare** NOS components are highly sought after by collectors and restorers, making this a valuable part for period-correct builds.

2. **Proven Reliability** The 3R4 carburetor was a staple in Yamaha s early four-stroke engines, known for smooth operation and durability when properly maintained.

3. **Easier to Source** Compared to some other vintage Yamaha parts, the 3R4 is relatively common, though NOS examples are harder to find.

4. **Compatibility** Fits Yamaha engines from the late 1970s to early 1980s, including the **YZ465 (1981)** and **IT250 (1981)**.

5. **Potential for Restoration Value** If preserved well, this part could appreciate in value over time, especially if demand for classic Yamaha engines grows.

**Cons:**

1. **Age-Related Wear** Even if the shaft is NOS, the carburetor may still show signs of aging, such as dried-out seals, minor corrosion, or worn internals.

2. **Maintenance Required** A carburetor this old will need cleaning, adjustment, and possibly rebuilding to function optimally.

3. **Limited Modern Availability** Some replacement parts (like gaskets or seals) may be difficult to source, requiring sourcing from specialty suppliers or vintage motorcycle shops.

4. **Potential for Misuse** If not installed correctly, an old carburetor could lead to poor fuel efficiency, rough idling, or even engine damage.

5. **Cost vs. Value** While valuable to collectors, the price may not justify the purchase if you re not restoring or building a show bike rather than a daily rider.

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#### **1981 Yamaha YZ465**

The **YZ465** was Yamaha s flagship dirt bike in the early 1980s, known for its aggressive styling, powerful single-cylinder engine, and competitive performance in motocross.

**Pros:**

1. **Classic Design & Performance** The YZ465 was a dominant bike in its era, with a strong engine and lightweight frame, making it a great choice for enthusiasts.

2. **Strong Aftermarket Support** Parts, upgrades, and restoration guides are widely available, including modern components for improved reliability.

3. **Great for Restoration or Racing** If you re building a bike for classic racing, trail riding, or show, the YZ465 is a fantastic platform.

4. **Resale Value for Collectors** Well-preserved examples can hold value, especially if they come with original components like the NOS carburetor.

5. **Modifiable for Modern Use** With the right upgrades (modern clutch, suspension, exhaust, and fuel system), it can be made into a functional daily rider.

**Cons:**

1. **High Mileage & Wear** Most YZ465s on the market today have significant mileage, meaning major work (engine rebuild, frame inspection, suspension refresh) may be needed.

2. **Original Parts Scarcity** Finding genuine 1981 parts (like the NOS carburetor) can be expensive or difficult, increasing restoration costs.

3. **Fuel & Emissions Challenges** Older bikes struggle with modern fuel (higher ethanol content can damage rubber seals), and emissions regulations may require modifications.

4. **Maintenance Intensity** Single-cylinder engines require more frequent tune-ups, valve adjustments, and chain/sprocket replacements than modern bikes.

5. **Riding Experience** While fun, the YZ465 lacks modern comfort features (ergonomics, suspension tuning, and electronics), making long rides less enjoyable.

---

#### **1981 Yamaha IT250**

The **IT250** was Yamaha s trail bike alternative to the YZ465, offering a more comfortable, touring-oriented version of the same engine.

**Pros:**

1. **Versatile & Comfortable** The IT250 was designed for trail and light off-road use, with a more upright riding position and better ergonomics than the YZ465.

2. **Same Engine as YZ465** Shares the same **250cc single-cylinder** powerplant, meaning the NOS 3R4 carburetor will fit and perform similarly.

3. **Lower Mileage Options Available** Since it was a trail bike, some examples may have been ridden less aggressively, preserving original components better.

4. **Easier to Modify for Dual-Sport Use** With the right tires and suspension adjustments, it can be a capable adventure bike.

5. **Nostalgic & Collectible** Like the YZ465, well-preserved IT250s are desirable to vintage motorcycle enthusiasts.

**Cons:**

1. **Less Aggressive Performance** The IT250 was not built for motocross, so it lacks the aggressive suspension tuning and lightweight frame of the YZ465.

2. **Higher Mileage Common** Many IT250s were used for daily trail riding, meaning they may have more wear than a race-bred YZ465.

3. **Limited Aftermarket Focus** While not as rare as some Yamahas, the IT250 doesn t have the same level of aftermarket support as the YZ465.

4. **Fuel & Modernization Issues** Similar to the YZ465, it may require fuel system upgrades to run efficiently on today s gasoline.

5. **Less "Hot" for Enthusiasts** The YZ465 is more iconic in the off-road community, making it potentially more valuable to collectors.

---

### **Conclusion & Recommendation**

#### **Overall Assessment:**

Buying a **1980 Yamaha 3R4-18101-01 (NOS shaft)** alongside a **1981 YZ465 or IT250** is a **great investment for collectors, restorers, or enthusiasts** who prioritize authenticity, nostalgia, and potential appreciation. However, it is **not a practical purchase for casual riders** who want a modern, low-maintenance off-road bike.

- **If you are restoring or building a show bike**, the NOS carburetor and a well-chosen YZ465/IT250 will significantly enhance authenticity and value.

- **If you plan to modify the bike for modern use**, the cost of restoration (engine rebuild, suspension, fuel system upgrades) may outweigh the initial savings of buying NOS parts.

- **If you are a collector**, this purchase could be a strong addition to a vintage Yamaha collection, especially if the bike is in good original condition.

#### **Recommendation:** 1. **Best for Collectors/Restorers:**

- **Proceed with the purchase** if you have the skills, tools, and patience to restore the bike properly.

- **Prioritize the YZ465** over the IT250 if you want a more aggressive, race-ready platform.

- **Budget for additional restoration costs** (engine rebuild, frame inspection, modern safety upgrades).

2. **Not Recommended for Casual Riders:**

- If you want a **functional, modernized off-road bike**, consider a **used YZ465 or IT250 with a modern engine rebuild** instead of chasing NOS parts.

- If you **must have original components**, focus on a **lower-mileage example** and be prepared for higher maintenance costs.

3. **Alternative Approach:**

- If the primary goal is **performance**, consider **modernizing the fuel system** (e.g., upgrading to a **Keihin carburetor or fuel injection**) rather than relying on an old NOS part.

- If the goal is **preservation**, ensure the bike is **fully documented** (service records, originality certificates) to maximize resale value.

#### **Final Verdict:**

This purchase is **ideal for dedicated vintage motorcycle enthusiasts** who value authenticity and are willing to invest time and money into restoration. For everyone else, a **modernized YZ465 or IT250** may be a more practical and enjoyable choice. If you proceed, **inspect the carburetor thoroughly** (check for leaks, wear, and functionality) before finalizing the deal.

Details:

NOS Yamaha OEM Shift Shaft Assembly 1980 YZ465 1981 IT250 3R4-18101-01.

part #: 3r41810101 prices

  • $45.00-$135.00

specifications cyclevintagee:

  • for models: Yz465, It250
  • for makes: Yamaha
  • for years: 1980-1981
  • mpn: 3r4-18101-01
  • part type: Shaft
  • unit type: Unit
  • machine type: Dual Sport Motorcycle
  • vintage part: Yes
  • compatible year: 1978
  • country of origin: Japan
  • performance part: No

returns cyclevintagee:

  • policy: No Returns

offer cyclevintagee:

  • quantity: 1
  • sold: 0
  • availability: In Stock
  • started: February 16, 2026
  • best offers: True
  • options: Ship-to-home

general cyclevintagee:

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

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  • wallet: Apple-pay
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seller cyclevintagee:

  • city: Tuttle, Oklahoma
  • rating: 96.2%
  • # reviews: 85

shipping cyclevintagee:

  • class: Standard
  • carrier: USPS
  • service: USPS Ground Advantage
  • type: Calculated
  • cost: $7.46
  • transit: 5-9 Days
for models: yz465, it250, for makes: yamaha, for years: 1980-1981, part type: shaft, unit type: unit, machine type: dual sport motorcycle, vintage part: yes, compatible year: 1978, country of origin: japan, performance part: no,
category: motorcycle parts > motorcycle scooter parts accessories, sku: 20640365625734633,
Yamaha 3R4-18101-01 Is Similar To:
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  • New other (see details). Offer #1 priced at $135.00 + $0.00 shipping estimate = $135.00* total. FREE SHIPPING
  • Used. Offer #2 priced at $45.00 + $8.06 shipping estimate = $53.06* total. NOS Yamaha OEM Shift Shaft Assembly 1980 YZ465 1981 IT250 .+$8.06 shipping

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