STARTING LINE PRODUCTS 3725-S551291-35 Slp Exhaust Flange Grafoil Seal Cat 136

( Brand: Starting Line Products ), ( Manufacturer Part Number: 3725-S551291-35 ), ( Part Type: Seal Exhaust Flange )

Review STARTING LINE PRODUCTS Slp Exhaust Flange Grafoil Seal Arctic Cat 136 fits MOUNTAIN EFI 600 2003

The **Starting Line 3725-S551291-35 SLP Exhaust Flange Grafoil Seal** is a precision-engineered aftermarket component designed specifically for the **2003 Arctic Cat Mountain 600 EFI 136** engine, ensuring a secure, leak-free connection between the exhaust manifold and the catalytic converter or muffler assembly. Crafted from high-performance **Grafoil (graphite-based) sealing material**, this flange gasket is engineered to withstand the extreme heat, vibration, and pressure generated during high-performance operation, making it an ideal choice for both stock and modified setups. The **SLP (Super Low Profile) design** minimizes bulk while maintaining structural integrity, allowing for a cleaner, more streamlined exhaust flow without compromising on sealing efficiency. This gasket features a **perfectly contoured fit** to match the exact dimensions of the Arctic Cat s exhaust flange, preventing gaps that could lead to exhaust leaks, reduced power, or premature wear on the surrounding components. Whether you're restoring factory performance, upgrading to a high-flow exhaust system, or addressing a leak in an existing setup, this gasket provides a reliable, long-lasting solution that resists warping, cracking, or degradation under prolonged use. Its **universal compatibility** with OEM fasteners ensures a straightforward installation, while its **heat-resistant properties** guarantee consistent sealing performance even under demanding conditions, making it a trusted upgrade for enthusiasts and professionals alike.

### **Pros and Cons of buying a Starting Line 3725-S551291-35 SLP Exhaust Flange with Grafoil Seal for a 2003 Arctic Cat Mountain 600 EFI (136cc)**

1. **OEM Fitment and Compatibility** This flange is designed specifically for the 2003 Arctic Cat Mountain 600 EFI, ensuring a proper fit without modifications. The part number (3725-S551291-35) is a direct replacement for the stock flange, reducing the risk of installation issues.

2. **SLP (Super Lightweight Performance) Construction** The SLP designation suggests that this flange is made from lightweight materials, which can improve exhaust flow and reduce overall weight. This may contribute to better throttle response and fuel efficiency, though the impact will depend on the rest of the exhaust system.

3. **Grafoil Seal Included** The inclusion of a Grafoil gasket ensures a reliable seal between the flange and the exhaust pipe or muffler. Grafoil is durable, heat-resistant, and resistant to oil and fuel, which helps prevent leaks over time. This can save money compared to purchasing a separate gasket.

4. **Aftermarket Support and Availability** Starting Line is a well-known brand in the ATV and snowmobile aftermarket, meaning this part is likely available from multiple dealers, online retailers, and specialty shops. This makes it easier to find and replace if needed.

5. **Potential Performance Benefits** If the stock flange was restrictive or damaged, replacing it with this SLP version could improve exhaust flow, leading to better engine performance, especially in cold starts or high-altitude conditions.

6. **Durability** The flange is likely constructed from high-quality materials designed to withstand the stresses of off-road use, reducing the likelihood of premature failure.

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1. **Cost Compared to Stock or Generic Parts** While not excessively expensive, this SLP flange may be more costly than a basic aftermarket or generic replacement. If the stock flange is still functional, there may be no need for an upgrade.

2. **Mixed Performance Gains** The lightweight nature of the SLP flange may not provide significant performance improvements unless the rest of the exhaust system is optimized. If the rest of the exhaust is restrictive (e.g., stock muffler), the benefits may be minimal.

3. **Potential Installation Challenges** If the flange was previously damaged or warped, replacing it may require additional effort to ensure a proper fit. Some users may need to clean or resurface mating surfaces to avoid leaks.

4. **Compatibility with Non-OEM Exhausts** While this flange fits the 2003 Arctic Cat Mountain 600 EFI, if you plan to install a non-OEM exhaust system, you may need to verify that the flange dimensions match the rest of the aftermarket components. Mismatches could lead to leaks or improper fitment.

5. **Limited Longevity Claims** Like most aftermarket parts, the lifespan of this flange depends on usage conditions. Heavy use, off-road abuse, or exposure to extreme temperatures could accelerate wear, though Grafoil should help mitigate some of these issues.

6. **No Warranty on Performance** While Starting Line likely offers a warranty on manufacturing defects, there is no guarantee that the flange will improve performance beyond stock levels. Results vary based on other system components.

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### **Conclusion and Recommendation**

The **Starting Line 3725-S551291-35 SLP Exhaust Flange with Grafoil Seal** is a solid choice for a 2003 Arctic Cat Mountain 600 EFI if you are experiencing issues with the stock flange, such as leaks, rust, or performance limitations. The SLP construction and Grafoil seal provide a reliable upgrade with minimal risk of installation problems. However, the performance gains may be modest unless paired with other exhaust modifications.

- Your stock flange is damaged, leaking, or worn out.

- You want a lightweight alternative to improve exhaust flow slightly.

- You prefer a trusted aftermarket brand with good availability.

- You plan to keep the rest of the exhaust system stock or are unsure about further modifications.

- Your stock flange is still in good condition and not causing issues.

- You are on a tight budget and can find a cheaper generic replacement.

- You intend to install a full aftermarket exhaust system and need to verify compatibility with other components.

- You expect dramatic performance improvements without additional upgrades (e.g., muffler, headers).

**Final Verdict:** This is a **reliable and practical upgrade** for most owners, especially those looking for a direct replacement with slight performance and durability benefits. It is a low-risk purchase that could pay off in the long run if the stock flange is failing.

Details:

2004 - 2006 Arctic Cat F6 Fire cat EFI Son Pro Twin Pipe. 2003 - Arctic Cat Mountain 600 EFI 136 Twin Pipe. SLP Exhaust Flange Grafoil Seal for 2003 Arctic Cat Mountain 600 EFI 136: For Systems.: Brand: Starting Line Products, model Number: 3725-S551291-35.

Parts without fitment are to be assumed universal and may require vehicle modification. This is helpful if you are buying multiple items. I need to exchange an item.

part #: 3725s55129135 price

• $57.87

specifications exhaustsnowmobilee:

• for models: Efi, 600, Mountain
• for makes: Arctic, Arctic-cat
• for years: 2003
• brand: Starting Line Products
• mpn: 3725-s551291-35
• part type: Seal Exhaust Flange

seller exhaustsnowmobilee:

• city: Boise, ID
• rating: 99.9%
• # reviews: 84695

payments exhaustsnowmobilee:

• credit card: Mastercard
• other
• wallet: Apple-pay

offer exhaustsnowmobilee:

• availability: In Stock
• quantity: 3
• started: May 6, 2026
• sold: 0
• options: Ship-to-home

returns exhaustsnowmobilee:

• policy: Returns Accepted
• time: 30 Days
• paid by: Seller

shipping exhaustsnowmobilee:

• transit: 3-8 Days
• type: Fixed
• service: Standard
• cost: $0.00
• class: Standard

general exhaustsnowmobilee:

• condition: New
• Parts Accessories > Snowmobile Parts > Exhaust

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