Dowel Pin – Fits Mercury/Parsun 4-6 HP Outboards (Replaces Mercury 16155)
Dowel Pin – Fits Mercury/Parsun 4-6 HP Outboards (Replaces Mercury 16155) is backordered and will ship as soon as it is back in stock.
Couldn't load pickup availability
Worry-free returns
Worry-free returns
You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).
You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Dowel Pin – Fits Mercury/Parsun 4-6 HP Outboards (Replaces Mercury ...
Product Details
This Dowel Pin – Fits Mercury/Parsun 4-6 HP Outboards (Replaces Mercury 16155) is a crucial component for the water pump assembly in Mercury and Parsun 2-stroke outboard engines from 4 to 5 HP, as well as 4-stroke models from 4 to 6 HP (1 cylinder). It ensures the impeller is securely locked to the driveshaft for optimal cooling performance.
Serves as a direct replacement for Mercury part number 16155 and Parsun part number PAT5-03000009.
- Installs in the lower unit as an impeller dowel pin.
- Used within the water pump impeller assembly.
- Weight: 0.0045 kg (0.01 lbs).
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Mercury | 16155 |
| Parsun | PAT5-03000009 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
This part is compatible with select 4-6 HP Mercury outboard engines. Please verify that your OEM part number is 16155.
This part is compatible with select 4-6 HP Parsun outboard engines. Please verify that your OEM part number is PAT5-03000009.
| Brand | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Mercury | 4 HP | 2-Stroke | 16155 | |
| Mercury | 5 HP | 2-Stroke | 16155 | |
| Mercury | 4 HP | 4-Stroke | 16155 | 1 Cylinder |
| Mercury | 5 HP | 4-Stroke | 16155 | 1 Cylinder |
| Mercury | 6 HP | 4-Stroke | 16155 | 1 Cylinder |
| Parsun | 4 HP | 2-Stroke | PAT5-03000009 | |
| Parsun | 5 HP | 2-Stroke | PAT5-03000009 | |
| Parsun | 4 HP | 4-Stroke | PAT5-03000009 | 1 Cylinder |
| Parsun | 5 HP | 4-Stroke | PAT5-03000009 | 1 Cylinder |
| Parsun | 6 HP | 4-Stroke | PAT5-03000009 | 1 Cylinder |
Technical Specs
- Product Type
- Dowel Pin
- Installation
- Impeller dowel pin
- Fitting Type
- Pin
- Technical Role
- Used in the water pump impeller assembly
- Dimensions
- Height: 0.3; Width: 10.0; Length: 8.0;
- Weight
- 0.0045 kg (0.01 lbs)
What’s in the Box
- 1x Dowel Pin
Installation Notes
- Disconnect the engine's battery and shift the outboard into neutral.
- Drain the gearcase oil from the lower unit.
- Remove the bolts securing the lower unit (gearcase) to the engine's upper section and carefully lower it.
- Unbolt and remove the water pump housing cover to access the impeller.
- Remove the old water pump impeller and locate the old dowel pin on the driveshaft. Remove it with pliers.
- Place the new dowel pin into its slot on the driveshaft.
- Align the keyway on the new impeller with the dowel pin and slide it down into position.
- Reassemble the water pump housing using new gaskets as recommended.
- Reinstall the lower unit, ensuring the driveshaft, shift shaft, and water tube are correctly aligned.
- Refill the lower unit with the correct grade of marine gear lube.
- Reconnect the battery and test the engine in a suitable water source, verifying a strong telltale stream.
Troubleshooting & FAQ
How do I know if this dowel pin fits my outboard?
This pin is specifically designed for Mercury and Parsun 2-stroke (4-5 HP) and 4-stroke (4-6 HP, 1-cylinder) outboards. The most reliable way to confirm fitment is by matching your engine's original part number to the cross-references provided (Mercury 16155). Please check your service manual if unsure.
Where is this dowel pin installed?
This dowel pin is installed on the main driveshaft inside the lower unit's water pump assembly. Its purpose is to lock the water pump impeller to the shaft, forcing it to spin and pump cooling water.
What are the signs of a failing dowel pin?
A sheared or missing dowel pin will prevent the impeller from spinning, leading to a complete loss of cooling water flow. This will cause the engine to overheat quickly, likely triggering an audible alarm and a noticeable stop in the "telltale" water stream.
When should I replace the dowel pin?
It is standard marine practice to replace the dowel pin every time you service the water pump and replace the impeller. This is typically recommended every 1-2 years or 100-200 operating hours, especially in saltwater environments.
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.
Payment & Security
Payment methods
Your payment information is processed securely. We do not store credit card details nor have access to your credit card information.
