When you're shopping for marine engines propulsion, you'll quickly find yourself comparing two very different ways to put power behind a boat. On one side is a used fresh-water MerCruiser 5.7 L V8 inboard at USD 4,999.00. On the other is a new HANGKAI 6.5hp four-stroke outboard at USD 699.90. One is built to shove a sizable hull through open water; the other is designed to be clamped onto a small boat and carried home. The right choice depends almost entirely on the boat you own and how much installation work you're ready to handle.
Quick verdict: If you're repowering an existing inboard hull and want big V8 displacement plus the familiarity of a MerCruiser-style package, the MerCruiser 5.7 L 350 V8 is the engine for that job. If you need a portable, new outboard for a tender, dinghy, or small skiff, the HANGKAI 6.5hp gives you a complete water-cooled motor at a small-boat price.
| Product | Price | Condition | What You Get | Best Match |
|---|---|---|---|---|
| MerCruiser Marine 5.7 L 350 V8 REMAN Inboard Engine | USD 4,999.00 | Used | Fresh-water V8 inboard, CW rotation, drop-in ready, bell housing included | Larger inboard boats and repower projects |
| HANGKAI 4 Stroke 6.5hp Outboard Motor | USD 699.90 | New | 123cc four-stroke outboard, water-cooled, CDI ignition, F-N-R, manual start | Small craft, dinghies, auxiliary power |
Where the MerCruiser wins: This is a full-size V8 inboard engine. The 5.7L displacement, CW rotation, and drop-in-ready describe a repower scenario where the existing engine mount and bell housing layout are already in place. The fresh-water designation also matters if you've been shopping through rust-prone saltwater examples. It's the bigger power source by a wide margin.
Where the HANGKAI wins: The HANGKAI is a complete, new outboard at a small-boat price. You get a 4-stroke 123cc engine with CDI ignition, water cooling, F-N-R shifting, and manual tilt in one portable package. Its short 40cm shaft and 4cm clamping width make it easy to mount on a transom and remove when you're done. For a small boat owner, that combination of portability and low cost is hard to beat.
MerCruiser Marine 5.7 L 350 V8 REMAN Inboard Engine
Choose this engine if your boat already has an inboard layout and you're looking for a high-displacement replacement. The engine is a fresh-water Mercruiser 5.7 with CW/RH rotation that runs great and is drop-in ready, with the bell housing still attached. That positions it as a repower-ready core rather than a bare long block. The limitation is the missing transmission: it's been removed and is not included in the sale. You'll need to source a compatible transmission and confirm that the bell housing matches your boat's coupling setup. Because it's used, you'll also want to make sure the CW rotation matches your current sterndrive or inboard configuration. This is not a portable motor; it's a stationary power plant for boats that are already set up for an inboard.
HANGKAI 4 Stroke 6.5hp Outboard Motor
The HANGKAI is the practical choice for small boats that don't need V8 muscle. This new outboard uses a 123cc four-stroke single with CDI ignition and water cooling, and it includes forward, neutral, and reverse gears. The manual start and tiller control keep the setup simple, while the 12L fuel tank and roughly 2L/hour consumption allow for extended cruising on lighter craft. It comes as a complete outboard, with the core components in one package. Its short shaft is sized for transoms around 40cm, and the 4cm clamping width gives you a stable mount on small boats. The main trade-off is output. At 6.5hp, you won't push a heavy hull or fight strong currents the way a V8 will. You also need to stick with #92 gasoline and four-stroke lubricant. It's a great auxiliary or primary motor for tenders and dinghies, not a replacement for a big inboard.
Final choice by use case:
- Repowering a larger fresh-water inboard boat where a V8 is expected: MerCruiser 5.7 L 350 V8.
- Fitting a small boat or dinghy with a new, portable outboard: HANGKAI 6.5hp.
