Recmar Mercury OptiMax Thermostat 143F 833072003 18-3536
REC833072003
- Dispatched in 2-3 days
- 30 Day Return Policy
- In stock, ready to ship
- Backordered, shipping soon
Recmar Mercury OptiMax Thermostat
143°F / 62°C | Replaces 833072003
Aftermarket thermostat for selected Mercury OptiMax direct-fuel-injected two-stroke outboards. Mercury used this thermostat across more than one OptiMax family, with serial boundaries that must be respected.
Key Features
- 143°F (approximately 62°C) thermostat specification
- For selected Mercury OptiMax DFI two-strokes
- Serial-range fitment stated below
- Aftermarket Recmar part; not genuine Mercury
- One thermostat supplied
Technical Specs
| Part type | Outboard cooling thermostat |
| Opening temperature | 143°F / approximately 62°C |
| Engine system | Two-stroke DFI / OptiMax |
| Quantity | 1 thermostat |
| 4Boats SKU | REC833072003 |
Compatibility / Fitment Guide
| Engine / system | Application | Fitment condition |
|---|---|---|
| Mercury OptiMax 75–115 hp | Specified DFI outboards | Serial 1B227000 onward where parts diagram lists 833072003 |
| Mercury OptiMax 135 / 150 / 175 hp | 2.5L DFI family | Common serial range 0T801000 through 1B226999; verify exact model |
| Johnson / Evinrude cross-reference applications | Only engines whose OEM/service catalogue crosses to the 437090 thermostat family | Confirm temperature, dimensions and gasket separately |
Not for every OptiMax or Mercury two-stroke. Earlier/later serial ranges, 3.0L 200–300 hp DFI families and engines updated by service bulletin can require different thermostat assemblies or covers. Not a MerCruiser inboard thermostat.
OEM Cross Reference
| Mercury / Mariner | 833072002; 833072003; 833072004 |
| Sierra | 18-3536 |
| OMC cross-reference family | 0437090; 5000355; 5005440 — verify application |
| Recmar / 4Boats SKU | REC833072003 |
Cross-reference numbers identify compatible service applications; they do not make this aftermarket Recmar part a genuine OEM component.
Questions & Answers
Will it fit every Mercury OptiMax?
No. Use the horsepower, displacement and serial boundaries in the fitment guide.
How many thermostats are required?
This listing supplies one; check the engine diagram for the quantity fitted.
Is it 143°F?
Yes, approximately 62°C.
Is a gasket included?
Only if clearly shown. Match and order the required seal separately when necessary.
Before ordering: match 833072003 in the serial-specific Mercury diagram and confirm the number of thermostats required.
For the products under £150 the shipping is £6.99.
Free delivery for most items over £150.
