The Multiquip 21755 is a genuine OEM Yanmar 55HP Service Muffler Gasket designed for Whiteman hydrostatic ride-on power trowel models STXD6i, HTXD6i, STX55J6, and STX55Y6. As a direct OEM replacement, part 21755 is produced to the same specifications as the original component, ensuring a proper seal between the exhaust manifold and muffler on Yanmar-powered trowel units. DHS Equipment supplies this part straight from the Multiquip OEM supply chain, so you receive the exact component your machine calls for. Confirm your model code against the fitment list before ordering to ensure compatibility.
Key Features
- Genuine OEM Sealing Integrity — Manufactured to original Multiquip specifications, this muffler gasket delivers the correct compression and heat resistance needed to maintain an airtight exhaust seal on Yanmar 55HP trowel engines.
- Direct Drop-In Replacement — Engineered to match the original mounting configuration on Yanmar 55HP powerplants, this gasket seats correctly against the muffler flange without rework or adjustment.
- Confirmed Fitment for STX and HTX Series — Verified for STXD6i, HTXD6i, STX55J6, and STX55Y6 Whiteman hydrostatic ride-on trowels powered by the Yanmar 55HP engine.
- Sustained Exhaust Performance — A properly seated muffler gasket prevents exhaust leaks that can reduce backpressure, cause excess heat buildup near the engine bay, and expose operators to exhaust gases during operation.
- Operator Safety Relevance — A failed or blown muffler gasket on a ride-on trowel can direct hot exhaust gases toward the operator platform; replacing it promptly with the correct OEM part is a straightforward safety measure.
The muffler gasket forms the sealing interface between the engine exhaust port or manifold and the muffler assembly. Its role is to contain combustion exhaust gases within the exhaust pathway, directing them safely away from the engine and operator while maintaining the back-pressure balance the engine depends on for efficient combustion. When a muffler gasket deteriorates, burns through, or is crushed unevenly, exhaust gases escape at the joint, producing audible ticking or hissing sounds, increased heat around the engine compartment, and potential performance loss. On a ride-on trowel where the operator sits close to the powerplant, a compromised exhaust seal is not just a maintenance issue — it is a working condition concern that warrants prompt attention.
Part Details
| Part Number | 21755 |
|---|---|
| Brand | Multiquip |
| Part Type | Genuine OEM |
| Description | Yanmar 55HP Service Muffler Gasket |
Compatibility & Fitment
| Name | Model |
|---|---|
| Whiteman Ride-On Power Trowels | STXD6i |
| Whiteman Ride-On Power Trowels | HTXD6i |
| Whiteman Ride-On Power Trowels | STX55J6 |
| Whiteman Ride-On Power Trowels | STX55Y6 |
Verify Before You Order
Fitment is machine-number and revision-specific; always confirm your model and serial number against the fitment list.
Why Buy From DHS Equipment
Every part is verified against the manufacturer's part number before it ships, so what you order is what arrives. We carry parts from leading OEM brands and our own DHS Quality Parts line of professional aftermarket components. Need help finding the right part? Our team is available to confirm compatibility whenever you need it. Orders are processed fast to keep your jobs on track. We don't just sell parts. We keep you jobsite ready.
Questions? Contact our team at [email protected] or 866-611-9369 — DHS Equipment is here to help you maintain peak performance.
