Sierra Serpentine Belt — Marine Inboard — 47-15103
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Sierra Serpentine Belt — Marine Inboard — 47-15103
A direct-fit replacement serpentine belt for compatible marine inboard and sterndrive engine applications. The serpentine belt drives critical engine accessories — including the alternator, raw water pump, and power steering pump — from a single continuous belt. Built to OEM specifications for reliable performance in the marine environment.
Key Features
- Direct-fit replacement for compatible marine inboard and sterndrive applications
- Drives engine accessories including alternator, raw water pump, and power steering pump
- Built to OEM fit and performance specifications
- 249g — lightweight and ready to install
Compatibility
- MerCruiser 7.4L & 8.2L: 1998–2001 454 Mag MPI Horizon MIE, 7.4L MPI MIE, and 8.2L MPI MIE engines.
- MerCruiser 454 Mag & 502 Mag: 1998–2001 MPI setups.
- MerCruiser 350 Mag: 2000–2004 Alpha configurations. [1]
Parts Desk Insights
Best use case: Serpentine belt replacement is a standard maintenance item on inboard and sterndrive engines — typically recommended every 2–3 seasons or at the first sign of cracking, glazing, fraying, or squealing. Because a single serpentine belt drives multiple accessories simultaneously, a belt failure can disable the raw water pump (causing overheating), the alternator (causing battery drain), and power steering in a single event. Inspect the belt tensioner and idler pulleys at the same time — a worn tensioner is a common cause of premature belt failure. Confirm engine model and serial number compatibility before ordering.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.