Cam Follower Kit – Fits Mercury/Mariner/Force 30-125 HP Outboards (Replaces 850315A1, 12239A1)
Cam Follower Kit – Fits Mercury/Mariner/Force 30-125 HP Outboards (Replaces 850315A1, 12239A1) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Cam Follower Kit – Fits Mercury/Mariner/Force 30-125 HP Outboards (...
Product Details
This Cam Follower Kit fits a wide range of Mercury, Mariner, and Force outboards. Applications include Mercury/Mariner 3 & 4 cylinder 50–125 HP 2-Stroke models (1987-current), 30–150 HP 4-Stroke models, and Force 75–120 HP outboards from 1996–1999.
It is a direct replacement for Mercury/Mariner OEM part numbers 850315A1 and the superseded part 12239A1.
- Installation Location: Lower Unit/Gearcase
- Primary Fuel Type: Gasoline
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket suppliers.
| Brand | Part Number | Notes |
|---|---|---|
| Mercury/Mariner | 850315A1 | Current Part |
| Mercury/Mariner | 12239A1 | Superseded by 850315A1 |
Engine & Model Compatibility
Confirm your engine model and year in the tables below to ensure proper fitment.
This kit is designed for various Mercury and Mariner 2-stroke and 4-stroke outboard models, as well as select Force outboards.
| Brand | Model | Rated HP | Stroke | Years | OEM Part No. | Notes |
|---|---|---|---|---|---|---|
| Mercury/Mariner | Outboard | 30 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 40 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 45 BODENSEE | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 45 JET | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 50 | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 50 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 50 BIGFOOT | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 50 EFI | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 55 | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 60 | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 60 BIGFOOT | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 60 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 60 EFI | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 65 JET | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 75 | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 75 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 75 DFI | 2-Stroke | 1987–current | 850315A1 | 3 cyl (1.5L) |
| Mercury/Mariner | Outboard | 80 JET | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 80 JET | 2-Stroke | 1987–current | 850315A1 | 3 cyl (1.5L) |
| Mercury/Mariner | Outboard | 90 | 2-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 90 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 90 DFI | 2-Stroke | 1987–current | 850315A1 | 3 cyl (1.5L) |
| Mercury/Mariner | Outboard | 100 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 115 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 115 DFI | 2-Stroke | 1987–current | 850315A1 | 3 cyl (1.5L) |
| Mercury/Mariner | Outboard | 115 EFI | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 115 Pro XS | 2-Stroke | 1987–current | 850315A1 | 3 cyl (1.5L) |
| Mercury/Mariner | Outboard | 125 | 4-Stroke | 1987–current | 850315A1 | Supersedes 12239A1 |
| Mercury/Mariner | Outboard | 125 DFI | 2-Stroke | 1987–current | 850315A1 | 3 cyl (1.5L) |
| Force | Outboard | 75 | 2-Stroke | 1999 | 850315A1 | |
| Force | Outboard | 90 | 2-Stroke | 1996–1999 | 850315A1 | |
| Force | Outboard | 120 | 2-Stroke | 1996–1999 | 850315A1 |
Technical Specs
- Product Type
- Cam Follower Kit
- Installation
- Lower Unit/Gearcase
- Fuel Type
- Gasoline
- Dimensions
- 13.0" L x 10.0" W x 1.5" H
What’s in the Box
- 1 x Cam Follower Kit (replaces 850315A1)
Installation Notes
- Safely disconnect the engine's battery and ignition system.
- Position a suitable container and drain the gearcase lubricant completely.
- Carefully detach and remove the lower unit (gearcase) from the outboard's midsection.
- Following your service manual, access the shift linkage area to locate the existing cam follower.
- Remove the old cam follower and any associated hardware, noting their orientation.
- Clean the area and install the new cam follower kit components.
- Reassemble the lower unit, ensuring all seals and gaskets are correctly seated.
- Refill the gearcase with the manufacturer-specified lubricant to the correct level.
- Reconnect the battery and test the shifting operation on the water.
Troubleshooting & FAQ
Will this kit fit my 150 HP Mercury 4-stroke engine?
While the product title notes a range up to 125 HP, specific application data confirms compatibility with certain 4-stroke models up to 150 HP. Please use the detailed compatibility table and cross-reference your specific engine model and year to ensure this is the correct part for your motor.
What is the difference between part 850315A1 and 12239A1?
Part number 850315A1 is the current OEM part number from Mercury Marine. It supersedes, or replaces, the older part number 12239A1. They are functionally identical, and this kit serves as a direct replacement for both.
How do I know if my cam follower is failing?
Common symptoms of a worn or failed cam follower include difficulty shifting into forward or reverse, grinding noises during shifting, or the drive popping out of gear. A visual inspection during a lower unit service may also reveal visible wear or damage to the part.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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