When you walk into the marine engines propulsion category, the first thing to sort out is whether your boat needs a whole new engine or just a new set of mounts. That's the fork in the road between the Yanmar 4LHA-STZP inboard marine diesel engine and the DF100 inboard engine motor mounts. One replaces the heart of your propulsion system; the other re-anchors the engine you already have. You're comparing a component with a complete propulsion unit, and that difference drives everything else. The mounts come as a pair, ready for a 4-point setup, while the engine arrives as a single unit that needs freight planning.
Quick verdict
If your boat needs a new powerplant, the Yanmar 4LHA-STZP delivers a four-stroke diesel package. If the engine already works and you're chasing vibration or alignment issues, the DF100 mounts solve that for $119.95-a much smaller investment than a $15,000 engine.
At a glance
| DF100 Engine Mounts | Yanmar 4LHA-STZP | |
|---|---|---|
| Price | $119.95 | $15,000.00 |
| Price context | ||
| Condition | New | Used |
| Country of origin | United States | Japan |
| What you get | Pair of aluminum motor mounts | Complete 200 HP diesel engine |
| Key specs | 4-point to 850 lb, 5/8-18 stud | 200 HP, 4-stroke |
Where each product wins
- DF100 Engine Mounts: Lower price, new condition, a low-profile design that needs only 1-7/8 inches of clearance, and a DF100 part number from BUSHINGS INC. The zinc dichromate plating and 850-pound capacity make it a straightforward fix for an engine that's still running but vibrating or out of alignment.
- Yanmar 4LHA-STZP: The complete engine option. It's a four-stroke inboard diesel from Japan, and it comes with a specific part number for identification. It replaces the whole powerplant, but you'll be dealing with sea-freight logistics.
Product notes
DF100 Inboard Engine Motor Mounts
What makes the DF100 appealing is that it gives you two fresh mounting points with an oil- and fuel-resistant elastomer element and zinc dichromate-plated steel parts. The low profile means you only need about 1-7/8 inches of clearance, which helps in tight engine bays. The catch is that this is strictly hardware: you still need a functional engine to attach. And because the stud is 5/8-18 with a 4-inch bolt center, you have to measure your existing mounts before buying. It's a solid fix for vibration or misalignment, but it won't solve a dead engine.
Yanmar 4LHA-STZP Inboard Marine Diesel Engine
The Yanmar 4LHA-STZP-the engine labeled 'tested ok'-is a used 200 HP four-stroke inboard diesel with a Japan origin and a clear part number. If you're repowering a boat, this gives you the complete engine to pull and replace, rather than just a bracket. The trade-offs are significant: it's sold without warranty, and it ships by sea from India to your nearest port, which means a 30-60 day wait and customs clearance work on your end-including the ISF filing for US ports and any local port charges. Customs duties are your responsibility; if they're not arranged, the shipment can be destroyed. This is a serious purchase for someone comfortable with international freight and the realities of importing a used marine engine. You're paying for the engine itself, not for white-glove delivery.
Final choice by use case
For a boat with a healthy engine that's suffering from worn mounts, the DF100 pair is the sensible buy. You get fresh, corrosion-resistant hardware that replaces aging mounting points. For a boat that needs a whole new powerplant, the Yanmar 4LHA-STZP is the complete answer-just be prepared for the logistics of ocean shipping and customs clearance. Match the scope of the job to the size of the purchase, and you'll steer in the right direction. If you're still torn, think in terms of the job you're actually doing: maintenance versus repower.
