--- product_id: 58725086 title: "Red Line (42904) V-Twin Primary Case Oil - Engine Oil (1 Quart Bottle)" brand: "red line" price: "¥13127" currency: JPY in_stock: true category: "Red Line" url: https://www.desertcart.jp/products/58725086-red-line-42904-v-twin-primary-case-oil-engine-oil store_origin: JP region: Japan --- # Friction-balanced for clutch & primary chain protection Operates across wide temperature range (Flash Point 232°C) Specifically for 1984+ V-Twin motorcycles Red Line (42904) V-Twin Primary Case Oil - Engine Oil (1 Quart Bottle) **Brand:** red line **Price:** ¥13127 **Availability:** ✅ In Stock ## Summary > ⚡ Ride smoother, shift stronger — the clutch oil your V-Twin deserves! ## Quick Answers - **What is this?** Red Line (42904) V-Twin Primary Case Oil - Engine Oil (1 Quart Bottle) by red line - **How much does it cost?** ¥13127 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/58725086-red-line-42904-v-twin-primary-case-oil-engine-oil) ## Best For - red line enthusiasts ## Why This Product - Trusted red line brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Wide Thermal Stability:** Maintains performance and protection from cold starts to high-heat conditions (Flash Point 232°C). - • **Clutch-Friendly Friction Balance:** Unique formula reduces clutch slip, delivering smoother engagement and enhanced power transfer. - • **Precision Engineered for V-Twins:** Tailored synthetic oil optimized for 1984-to-present American V-Twin engines and aftermarket equivalents. - • **Racing-Proven Synthetic Technology:** Developed by Red Line since 1979, trusted by enthusiasts for uncompromising performance gains. - • **Enhanced Wear & Temperature Control:** Reduces wear on primary chain and clutch components, extending engine life and reliability. ## Overview Red Line (42904) V-Twin Primary Case Oil is a full-synthetic, friction-balanced lubricant designed specifically for 1984 and newer American V-Twin motorcycle engines. Engineered to optimize clutch operation and protect the primary chaincase, it operates effectively across a wide temperature range with a high flash point of 232°C. Trusted since 1979 by racing enthusiasts, this oil reduces wear and heat while enhancing power delivery in both stock and modified engines. ## Description Everyone thinks about the transmission side, but the clutch and primary chain need love, too. POWERSPORTS GEAR OIL Full-synthetic formulations specific to the latest V-Twins, UTVs, ATVs and Sportbikes Red Line's V-twin primary case oil is designed specifically for 1984-to-present V-Twin American motorcycle engines, including aftermarket engines of similar designs. Similar to Red Line MTL, this product is for use in the primary chaincase with wet-diaphragm spring clutches. Designed to operate over a wide temperature range, V-twin primary case oil improves clutch operation while reducing wear and temperature. Where most synthetics are too slippery for clutch operation, this friction-balanced product is designed to provide less slip, smoother operation, and more power in modified engines. SINCE 1979 In 1979, Red Line Synthetic Oil began creating lubricants for the racing industry. Today, we manufacture more than 100 quality products, including motor oils, gear oils, assembly lubes, fuel additives and our popular WaterWetter cooling additive for the automotive, motorcycle, marine and industrial markets. TECHNOLOGY Using cutting edge technology, Red Line responds to the technical challenges of today's performance industry. We are enthusiasts that stay on top of each market niche, ensuring product recommendations that result in serious performance gains. We use this knowledge of racing to create high-performance products for track cars and street vehicles. Red Line products perform and protect better than any on the market. No compromises. Everyone thinks about the transmission side, but the clutch and primary chain need love, too. POWERSPORTS GEAR OIL Full-synthetic formulations specific to the latest V-Twins, UTVs, ATVs and Sportbikes Red Line's V-twin primary case oil is designed specifically for 1984-to-present V-Twin American motorcycle engines, including aftermarket engines of similar designs. Similar to Red Line MTL, this product is for use in the primary chaincase with wet-diaphragm spring clutches. Designed to operate over a wide temperature range, V-twin primary case oil improves clutch operation while reducing wear and temperature. Where most synthetics are too slippery for clutch operation, this friction-balanced product is designed to provide less slip, smoother operation, and more power in modified engines. SINCE 1979 In 1979, Red Line Synthetic Oil began creating lubricants for the racing industry. Today, we manufacture more than 100 quality products, including motor oils, gear oils, assembly lubes, fuel additives and our popular WaterWetter cooling additive for the automotive, motorcycle, marine and industrial markets. TECHNOLOGY Using cutting edge technology, Red Line responds to the technical challenges of today's performance industry. We are enthusiasts that stay on top of each market niche, ensuring product recommendations that result in serious performance gains. We use this knowledge of racing to create high-performance products for track cars and street vehicles. Red Line products perform and protect better than any on the market. No compromises. ## Features - For best performance, follow the manufacturer's recommendations in your vehicle owner’s manual. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0053O9EUA | | Automotive Fit Type | Vehicle Specific Fit | | Best Sellers Rank | 238,059 in Automotive ( See Top 100 in Automotive ) 1,569 in Car Engine Oils | | Brand Name | Red Line | | Compatible with Vehicle Type | Motorcycle | | Container Type | Bottle | | Customer Reviews | 4.8 4.8 out of 5 stars (2,531) | | Flash Point | 232 Degrees Celsius | | Global Trade Identification Number | 00083522429047 | | Included Components | Red Line (42904) V-Twin Primary Case Oil - Engine Oil (1 Quart Bottle) | | Item Type Name | Motor Oils | | Item Weight | 771 g | | Liquid Volume | 32 Fluid Ounces | | Manufacturer | Red Line | | Manufacturer Part Number | 42904 | | Model Number | 42904 | | Number of Packs | 1 | | Part Interchange Info | 42904 | | Size | 1 Quart | | UPC | 083522429047 | | Unit Count | 946.3529 millilitre | ## Product Details - **Brand:** Red Line - **Flash point:** 232 Degrees Celsius - **Liquid volume:** 32 Fluid Ounces - **Package information:** Bottle - **Vehicle service type:** Motorcycle ## Images ![Red Line (42904) V-Twin Primary Case Oil - Engine Oil (1 Quart Bottle) - Image 1](https://m.media-amazon.com/images/I/71pFEcmeYZL.jpg) ## Available Options This product comes in different **Size** options. ## Questions & Answers **Q: What color is the fluid?** A: The primary case fluid is amber colored. You may be thinking about the Heavy Shockproof Transmission fluid which is pink. **Q: Can this be used in a can am outlander atv?** A: this is for a wet clutch where the transmission and primary do not share the same fluid **Q: Any compatibility issues removing amsoil from primary and replacing with red line?** A: Don't know I was running HD primary oil but I don't think there would be any issues it doesn't circulate through the engine or tranny. **Q: What computer part on my Harley-Davidson can I put on and hook up to the computer to get in more rapid response from my throttle** A: You need a tuner from Harley, or another maker,TTS3 , etc. and program to be able to talk to your CPU . The connection is under my seat,it differs with year and model bike. ## Frequently Bought Together - Red Line 42904 V-Twin Primary Case Oil, for use with UTVs, ATVs and Sportbikes - 1 Quart - Red Line 42804 V-Twin Transmission Oil with Shockproof - 4 Quarts - K&N Motorcycle Oil Filter: High Performance, Premium, Designed to be used with Synthetic or Conventional Oils: Fits Select Harely Davidson Motorcycles, KN-171B --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/58725086-red-line-42904-v-twin-primary-case-oil-engine-oil](https://www.desertcart.jp/products/58725086-red-line-42904-v-twin-primary-case-oil-engine-oil) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-10-19*