BARR MC-20-865996A3 Spacer Kit 1.7

( Brand: Barr ), ( Manufacturer Part Number: MC-20-865996A3 ), ( Part Type: Spacer ), ( Country Of Origin: United States )

Review BARR 1.7 Inch Spacer Kit fits MERCRUISER MARINE

The **Barr MC-20-865996A3 Marine 1.7" Spacer Kit for Mercruiser** is a meticulously engineered aftermarket solution designed to enhance the performance, reliability, and longevity of Mercruiser outboard and sterndrive applications, particularly those featuring the 1.7" (or 43mm) input shaft interface. This high-quality spacer kit is crafted from precision-machined, corrosion-resistant materials, ensuring durability in the harsh marine environment where saltwater, vibration, and constant motion can compromise standard components. The kit is specifically tailored to address common issues associated with Mercruiser drivetrains, such as excessive wear on input shafts, universal joints, and transmission housings, which often result from misalignment or inadequate spacing between the engine and the transmission. By providing a custom-fit, adjustable spacer assembly, this kit restores proper shaft alignment, reduces torsional stress on drivetrain components, and minimizes the risk of premature failure in critical areas like the input shaft yoke, splines, and transmission input bearings. Ideal for both new installations and retrofits, the Barr MC-20-865996A3 kit is compatible with a wide range of Mercruiser models, including but not limited to the 5.0L V8, 4.6L V8, and 4.3L V6 engines, as well as their corresponding Alpha, Beta, and Delta II sterndrive systems. Whether used to correct factory misalignment issues, accommodate aftermarket modifications, or extend the service life of an existing drivetrain, this spacer kit represents a cost-effective upgrade that professional marine technicians and DIY enthusiasts alike rely on for superior drivetrain performance. Its robust construction and ease of installation make it a trusted choice for those seeking to optimize power transfer, reduce vibration, and prevent costly repairs in their Mercruiser-powered vessels.

### **Pros and Cons of buying a Barr MC-20-865996A3 Marine 1.7L Mercruiser Spacer Kit**

The **Barr MC-20-865996A3 Marine 1.7L Mercruiser Spacer Kit** is designed to address timing chain stretch and excessive noise in older **Mercruiser 1.7L (170) engines**, particularly in boats with high-mileage or poorly maintained engines. Below is a detailed breakdown of its advantages and drawbacks.

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### **Pros**

1. **Addresses Timing Chain Issues**

The primary purpose of this spacer kit is to compensate for **timing chain stretch**, which can cause misfires, poor performance, and excessive engine noise. Installing the correct spacer restores proper timing, improving engine reliability and efficiency.

2. **Cost-Effective Alternative to Engine Replacement**

Replacing a severely worn 1.7L Mercruiser engine can cost **$3,000 $6,000 **, including labor. The spacer kit is a **fraction of that cost** (typically **$100 $200**), making it a practical solution for engines that would otherwise require a full rebuild or replacement.

3. **Minor Modification with No Major Engine Work Required**

Unlike a full engine overhaul, installing the spacer kit is a **relatively simple procedure** that can be done by a skilled mechanic in a few hours. It does not require disassembling the engine or replacing major components like the crankshaft or camshaft.

4. **Potential to Extend Engine Life**

If the engine s timing issues are due to chain stretch rather than internal wear (e.g., worn bearings, pistons, or rods), the spacer kit can **buy time** before a full rebuild becomes necessary. This is particularly useful for older boats where a full engine swap is impractical.

5. **Widely Available and Compatible**

The Barr kit is a **well-known aftermarket solution** for the 1.7L Mercruiser, meaning parts are easy to find, and installation guides are widely available. Many marine mechanics have experience working with it.

6. **May Reduce Oil Consumption (If Chain Slack Was Causing Leaks)**

In some cases, a stretched timing chain can cause **oil leaks** (e.g., from the oil pump or chain tensioner). Correcting the timing with a spacer may **reduce oil consumption** if the issue was chain-related.

7. **Good for High-Mileage Engines That Still Run Well**

If an engine has **150,000 miles** but is otherwise in decent condition, the spacer kit can **restore proper timing without requiring a full rebuild**, making it a viable option for keeping the boat operational.

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### **Cons**

1. **Does Not Fix Underlying Engine Wear**

The spacer kit **only addresses timing chain stretch** it does **not** repair worn bearings, pistons, rods, or cylinder walls. If the engine has **internal mechanical wear**, the spacer will not prevent future failures. A **compression test** or **engine analysis** is recommended before purchasing.

2. **May Not Work on Severely Damaged Engines**

If the engine has **excessive play in the crankshaft, worn camshaft lobes, or severe cylinder wear**, the spacer will not resolve those issues. In such cases, a **full rebuild or engine swap** is necessary.

3. **Requires Professional Installation**

While the installation is **not extremely difficult**, it **must be done correctly** to avoid **timing issues, oil leaks, or damage to the engine**. A **skilled marine mechanic** should perform the work to ensure proper alignment and torque specifications are met.

4. **Potential for Increased Oil Consumption (If Not the Root Cause)**

If the engine s oil consumption is due to **worn piston rings, valve seals, or a leaking PCV system** rather than the timing chain, the spacer kit will **not fix that**. In some cases, it might even **mask the real problem**, leading to further damage if unaddressed.

5. **Limited Longevity**

The spacer kit **does not prevent future chain stretch** it only compensates for existing wear. Eventually, the timing chain will stretch further, and the spacer may need to be **upgraded or replaced** with a thicker one. Some owners report needing **multiple spacers** over time.

6. **May Void Some Warranties (If Applicable)**

If the boat is under warranty, installing an aftermarket spacer kit **may void coverage**, especially if the manufacturer considers it an unauthorized modification. Always check warranty terms before proceeding.

7. **Not a Permanent Fix for All Engines**

Some 1.7L Mercruiser engines **develop other issues** (e.g., oil pump failure, rod bearing wear) that the spacer does not address. A **pre-purchase inspection** is strongly recommended to assess the engine s overall condition.

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### **Conclusion**

The **Barr MC-20-865996A3 Marine 1.7L Mercruiser Spacer Kit** is a **cost-effective, relatively simple solution** for addressing **timing chain stretch** in older Mercruiser 1.7L engines. It is best suited for **high-mileage engines that still run well but have excessive noise or timing issues** due to chain wear.

However, it is **not a cure-all** it **does not fix internal engine wear**, and improper installation or reliance on it without addressing other issues can lead to **further damage**. Before purchasing, **a thorough engine inspection** (including compression test, oil analysis, and timing check) is essential to determine if the spacer is the right solution.

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### **Recommendation**

The engine has **timing chain stretch** (confirmed by a mechanic).

The engine **runs well otherwise** (no major internal wear).

You are **prepared for potential future chain stretch** (may require additional spacers).

You have a **reliable mechanic** to install it correctly.

The engine has **severe internal wear** (worn bearings, pistons, or rods).

The engine **consumes excessive oil** due to other causes (e.g., piston rings, valve seals).

You are **unable to verify the exact issue** (always get a professional diagnosis first).

The boat is **under warranty**, and the modification may void coverage.

1. **Get a professional inspection** (compression test, timing check, oil analysis).

2. **Confirm that timing chain stretch is the primary issue.**

3. **If approved, have a mechanic install the spacer kit.**

4. **Monitor engine performance** if noise or misfires persist, further diagnostics are needed.

5. **Consider a full engine rebuild or swap** if internal wear is significant.

For most **older, high-mileage 1.7L Mercruiser engines with timing issues but no major internal damage**, the spacer kit is a **smart, budget-friendly upgrade** that can **restore reliability and extend the engine s life**. However, it should **never be considered a replacement for proper maintenance or a full engine overhaul** when necessary.

Details:

Spacer plate height 1.7 inches For use with raw water cooled RWC applications msrp $650.00.

part #: mc20865996a3 prices

• $546.24-$2066.49

specifications ouboaen:

• for models: Marine, Mercruiser
• brand: Barr
• mpn: Mc-20-865996a3
• part type: Spacer
• country of origin: United States

returns ouboaen:

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

general ouboaen:

• condition: New
• Boat Parts > Outboard Engines Components > Exhaust Systems

shipping ouboaen:

• transit: 4-9 Days
• class: Standard
• carrier: UPS
• cost: $22.12
• type: Calculated
• service: UPS Ground

seller ouboaen:

• # reviews: 151
• rating: 100.0%
• city: Pasadena, Maryland

payments ouboaen:

• other
• wallet: Paypal
• credit card: Mastercard

offer ouboaen:

• quantity: 1
• sold: 0
• availability: In Stock
• options: Ship-to-home
• started: March 7, 2026

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