Timing Belt 463377 for Volvo Penta AQ151 AQ125A AQ131 230 250 Marine Engine
Timing Belt 463377 for Volvo Penta AQ151 AQ125A AQ131 230 250 Marine Engine
Product Overview
Timing belt for the Volvo Penta AQ120, AQ125, AQ131, AQ140, AQ145 and AQ151 engines and the 230 and 250 models, supplied as 1 x timing belt. This is the belt that keeps the camshaft timed to the crankshaft on the B21, B23 and B25 four cylinder engines. It replaces Volvo Penta 463377, it crosses to Sierra 18-4029, and it fits the 19 models listed in the table below.
The timing belt is the one belt on the engine that cannot fail safely. If it strips or snaps, the camshaft stops while the crankshaft keeps turning, and the pistons meet the valves. On these engines that is a head off job at best.
It gives warnings before it goes. The teeth start to round off on the drive side, the belt runs loose, and the back of the belt cracks. A belt with a shiny, polished tooth profile has been running loose and is close to stripping.
The other thing that takes these belts out is an oil leak. Oil softens the rubber, and a timing belt that has been running in oil goes soft and loses its teeth long before the mileage is up. If the engine leaks at the front seal, fix the leak before fitting a new belt.
The number on the belt is 463377. The Sierra number for the same belt is 18-4029.
Specifications & Attributes
| Specification | Detail |
|---|---|
| Condition | New / New with tags |
| Type | Timing belt |
| Volvo Penta Part Number | 463377 |
| Sierra Number | 18-4029 |
| Engine Family | B21, B23 and B25 four cylinder |
| Fits | Volvo Penta AQ120, AQ125, AQ131, AQ140, AQ145, AQ151, BB140, BB145, 230 and 250 |
| Models | 19 models in 3 engine families, see the table below |
| Parts In Kit | 1 piece |
| Quantity | 1 timing belt |
| Net Weight | 115 g including packaging |
| Packaging | Pack |
| Warranty | 3 year |
OEM Cross Reference
| Component | Numbers |
|---|---|
| Timing belt | 463377 |
| Sierra | 18-4029 |
Compatible Engines
| Model | Engine Family |
|---|---|
| AQ120B | B21 / B23 / B25 |
| AQ125A | B21 / B23 / B25 |
| AQ125B | B21 / B23 / B25 |
| AQ131A | B21 / B23 / B25 |
| AQ131B | B21 / B23 / B25 |
| AQ131C | B21 / B23 / B25 |
| AQ131D | B21 / B23 / B25 |
| AQ140A | B21 / B23 / B25 |
| AQ145A | B21 / B23 / B25 |
| AQ145B | B21 / B23 / B25 |
| AQ151A | B21 / B23 / B25 |
| AQ151B | B21 / B23 / B25 |
| AQ151C | B21 / B23 / B25 |
| BB140A | B21 / B23 / B25 |
| BB145A | B21 / B23 / B25 |
| 230A | B21 / B23 / B25 |
| 230B | B21 / B23 / B25 |
| 250A | B21 / B23 / B25 |
| 250B | B21 / B23 / B25 |
These are the 19 models given on the listings for this belt. All of them are built on the Volvo Penta B21, B23 or B25 four cylinder petrol engine, and the same timing belt is used across all three.
The listings do not give years for any of these models, and on a timing belt the tooth count and the belt profile change with the engine build. If your engine is not in the table, send us the model, the year and the engine serial number and we will check the belt against it before you order.
What's Included
| Component | Detail | Qty |
|---|---|---|
| Timing belt | 463377, the belt that times the camshaft to the crankshaft | 1 |
| Tensioner | Not included | 0 |
| Water pump | Not included | 0 |
This listing is for the timing belt on its own. The tensioner and the water pump that runs off the same belt are separate parts and are normally changed at the same time.
Key Features
| Feature | Detail |
|---|---|
| Direct replacement | Fits in place of Volvo Penta 463377 |
| Cross referenced | Sierra 18-4029 |
| Three engine families | B21, B23 and B25 four cylinder |
| 19 models | AQ120 through to the 250, all listed above |
| AQ and BB models | Covers both the AQ and the BB designations |
| Service part | The belt to change before it strips |
Signs The Timing Belt Needs Changing
| What You See | What It Means | Action |
|---|---|---|
| Teeth rounded or shiny on the drive side | Belt running loose, close to stripping | Fit a new timing belt and a tensioner |
| Cracks across the back of the belt | Rubber hardened with age | Fit a new timing belt |
| Belt soft and swollen | Oil contamination from a front seal leak | Fix the leak, then fit a new belt |
| Whine or ticking from the front of the engine | Belt or tensioner bearing worn | Check the belt and the tensioner |
| Engine runs rough or backfires | Cam timing moved a tooth | Check the timing and fit a new belt |
| Unknown service history | Belt may be past its life | Fit a new timing belt, tensioner and water pump |
Fitting Notes
| Step | Action |
|---|---|
| 1 | Check the engine model and family against the table above |
| 2 | Bring the engine to top dead centre on number one and note the timing marks on the cam and crank pulleys |
| 3 | Take the front cover off and release the tensioner |
| 4 | Take the old belt off and check the water pump and tensioner for play and leaks |
| 5 | Line up the timing marks before the new belt goes on |
| 6 | Fit the new belt without turning either pulley, keeping the run between the cam and crank tight |
| 7 | Set the tensioner and turn the engine over by hand twice, then check the marks line up again |
| 8 | Refit the cover, start the engine and check the ignition timing |
Condition & Warranty
| Item | Detail |
|---|---|
| Condition | New / New with tags |
| Warranty | 3 year |
| Packaging | Pack |
Before You Buy
- Timing belt for Volvo Penta AQ and 230 and 250 marine engines
- Replaces Volvo Penta 463377
- Crosses to Sierra 18-4029
- Fits the B21, B23 and B25 four cylinder engines
- Fits the AQ120B, AQ125A and AQ125B
- Fits the AQ131A, AQ131B, AQ131C and AQ131D
- Fits the AQ140A, AQ145A, AQ145B, BB140A and BB145A
- Fits the AQ151A, AQ151B, AQ151C, 230A, 230B, 250A and 250B
- 115 g with packaging
- 30-Day Easy Returns
- Free Worldwide Shipping
Verfügbarkeit für Abholungen konnte nicht geladen werden
Boat Owners' Review
Before You Buy
Frequently Asked Questions
What is your refund policy?
We offer a 14-day hassle-free return on all products. Items must be unused and in original packaging. Every XRmarine part is also covered by our 1-year warranty against manufacturing defects. If something is not right, email us at info@xrmarineparts.com — replacement or full refund, your choice.
See our full Refund Policy for complete details.
How does shipping work?
Free international shipping on every order — no minimums. We operate a global warehouse network with a main distribution centre in Asia (10-20 business days). We also hold stock in regional warehouses across the United States, Germany, the United Kingdom, Australia, and Poland (opening soon) — most orders arrive in 1-3 business days within those countries and in 2-8 business days to nearby regions. Tracking included.
See our full Shipping Policy.
How do you keep prices fair?
We cut out the middlemen. XRmarine sources directly from quality manufacturers and sells at honest prices. Same OEM-quality parts, no dealership markup. Every order comes with free shipping, real expert support, and a 1-year warranty.
Learn more on our About Us page.
What payment methods do you accept?
We currently accept PayPal — a fast, secure way to pay online. Credit card payments (Visa, Mastercard, American Express) and Shopify Payments are being set up and will be available soon. We appreciate your patience.