# Parts Sourcing — Yamaha YL1

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## Parts Philosophy

The YL1 is a 1964–1968 motorcycle. Many OEM parts are no longer available from Yamaha dealers. Sourcing requires patience and multiple channels. **Buy parts when you find them** — availability changes daily.

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## OEM Part Number Structure

Yamaha part numbers follow the format: `XX0-XXXXX-XX-XX`

For the YL1:
- Prefix `116` or `137` appears on many YL1 parts (varies by year).
- When searching, enter the base 10-digit number (drop the last 4 digits if searching cross-references).

Record the OEM number for every part you order, whether you end up using it or not — it builds a reference library for future work.

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## Sourcing Channels

### New Old Stock (NOS)
The most desirable option — original Yamaha parts, never installed.

| Source | Notes |
|---|---|
| eBay | Largest single source; search by part number. Set up saved searches. |
| Vintage Yamaha parts dealers | See list below |
| Yahoo Japan Auctions | Excellent source for Japanese-market parts; use a proxy buyer service (Buyee, From Japan, Zenmarket) |
| Motorcycle swap meets / autojumbles | AHRMA events, Barber Vintage Festival, regional swap meets |

### Reproduction / Aftermarket
Quality varies enormously. Acceptable for non-critical parts (gaskets, seals, fasteners); use caution for engine internals and safety-critical parts (brake shoes, wheel bearings).

| Source | Notes |
|---|---|
| Cmsnl.com | OEM parts lookup and sales; ships internationally |
| Partzilla.com | OEM cross-reference and aftermarket |
| MikesXS / similar vintage Japanese vendors | Electrical components, carb kits |
| Vintage Connections | YL1/AS1/HS1 specialist |
| SirParts (Japan) | Japanese NOS warehouse; proxy buyer needed |

### Salvage
Complete parts bikes, engine cores, and used assemblies.

| Source | Notes |
|---|---|
| eBay "parts or not running" listings | Filter for YL1, YL2, AS1, YJ1 — many share components |
| Cycle Exchange / vintage bike dealers | In-person inspection advised for engine cores |
| Old Bike Mart (UK) | Strong vintage Japanese parts market in UK |
| CycleTrader / Facebook Marketplace | Occasional parts bikes locally |

### Machine work
- **Cylinder boring:** Any competent machine shop can bore to +0.25/+0.50mm oversize. Bring the piston so they can establish correct clearance.
- **Crank truing/pressing:** Requires a specialist. Kawasaki and 2-stroke racing shops often have crank truing stands. Do not attempt without the equipment.
- **Valve seats (N/A for 2-stroke).**

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## Cross-Reference — Compatible Models

The YL1 shares many components with related Yamaha models. When YL1-specific parts are unavailable, check:

| Model | Years | Note |
|---|---|---|
| Yamaha YL2 | 1968–1972 | Direct descendant; many parts interchange |
| Yamaha AS1 / AS2 | 1969–1972 | 100cc twin; many engine internals compatible |
| Yamaha HS1 | 1970–1971 | 90cc twin; close but not all internals interchange |
| Yamaha YJ1 | 1964–1968 | 55cc single; some chassis parts |

**Always verify dimensions before swapping cross-reference parts into a critical assembly.**

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## Key Consumable Parts to Order First

Before beginning disassembly, order these items — they will be needed regardless of what you find:

| Part | OEM or equivalent | Notes |
|---|---|---|
| Crank seal set (complete, both cylinders) | `93101-20070` (LH), verify | Critical — do not skip |
| Head gaskets (set of 2) | YL1-specific | New at reassembly — never reuse |
| Base gaskets (set of 2) | YL1-specific | New at reassembly |
| Crankcase gasket / sealant | Three Bond 1215 | Seals case mating surfaces |
| Points set (×2) and condensers (×2) | Points: `131-81621-00` (verify) | Replace as set |
| Spark plugs (×2) | NGK B7HS | Standard heat range |
| Fuel petcock rebuild kit | Diaphragm + O-rings | If vacuum-operated petcock |
| Carburetor rebuild kit (×2) | Mikuni VM16SS kits | Jets, needle, O-rings, float valve |
| Brake shoes (front and rear) | Verify drum diameter | |
| Fork seals (×2) | Per fork tube OD | |
| Fork oil | SAE 10W | Per fork specification |
| All fuel lines | 6mm ID fuel hose | Replace all rubber |
| Battery | 6V AGM, 4–6 Ah | |

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## Budget Planning

A realistic budget breakdown for a thorough YL1 restoration (US prices, 2025–2026):

| Category | Estimated range |
|---|---|
| Engine rebuild (parts only, no machine work) | $150–$350 |
| Machine work (bore, crank true if needed) | $100–$400 |
| Carburetor rebuild (×2) | $60–$150 |
| Electrical (points, condensers, rectifier, battery) | $80–$180 |
| Tires (×2) | $100–$200 |
| Wheel bearings, fork seals, brake shoes | $80–$160 |
| Fastner hardware replacement | $30–$60 |
| Gaskets, seals throughout | $80–$200 |
| **Subtotal (mechanical)** | **$680–$1,700** |
| Paint/powder coat (frame, tins) | $300–$1,200+ |
| Chrome replating (if any) | $200–$600+ |
| **Total estimated** | **$1,200–$3,500+** |

Prices vary widely with condition of the original parts. A cleaner donor bike reduces consumable spend significantly.

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## Keeping Records

Log every part ordered in `02_Engine_L1-47603/Parts_Log.md`:
- OEM part number
- Supplier and order date
- Price paid
- Condition on receipt
- Whether it was installed

This data is invaluable if the bike is ever sold, and prevents re-ordering parts you already have.