KUS Marine Coolant Temperature Sensor – Precise Engine Temperature Measurement for Inboard and Outboard Engines

Prevent major engine damage caused by unnoticed overheating! The original KUS coolant temperature sensors continuously measure the thermal load directly within the internal cooling circuit of your boat’s engine. They convert temperature readings into the standardized analog resistance range of 300 to 23 ohms. This makes these sensors the precise, error-free partners for all analog and digital KUS coolant temperature gauges (40–120°C) at your helm station.

The extremely wide range includes metric and imperial threads as well as various shaft lengths to fit perfectly into engine blocks from well-known manufacturers (e.g., Volvo Penta, Yanmar, MerCruiser, Yamaha, Mercury). The housings, made of high-purity marine brass, guarantee excellent thermal conductivity for lightning-fast response times in the event of thermal issues.

📐 A direct comparison of the 4 KUS sensor types:

Please measure the thread, the sensor diameter (Ø), and the required shaft length (L1) on your engine block before purchasing:

Type I & Type II (Standard): Classic analog temperature sensors without an additional integrated alarm contact. Type II features an extended housing.
Type III (Combination Sensor with Warning Contact): These models have a 2-pin connector. They provide a continuous clock signal AND, when the limit temperature is reached (95°C, 98°C, or 107°C, depending on the variant), activate an internal switch to trigger a separate warning buzzer or an alarm LED.
Type IV (Special Dimensions / NPT): Optimized probe lengths with American NPT tapered threads for U.S. engine systems.

Advantages & Technical Highlights at a Glance:

Highest signal precision: Precisely calibrated to the KUS characteristic curve (approx. 300 ohms at 40°C to 23 ohms at 120°C) for an absolutely flicker-free digital or analog display.
Rugged marine-grade brass: Completely corrosion-resistant against hot coolant, antifreeze, engine oils, and salt-laden bilge moisture.
Fully encapsulated, IP67-rated: The connector head is completely sealed against dust and water—providing maximum protection against leakage currents and oxidized contacts.
Universal compatibility: Can be used without restriction in all **12-volt and 24-volt** onboard systems.

🛠️ Accessory tip from Tenten-Boats:

Do you already have the right gauge? Order the visually perfectly matched KUS analog coolant temperature gauge (52 mm) or the modern KUS digital LCD coolant temperature gauge right along with it!

Technical Data (Specifications):

KUS Type	Thread Size	Sensor (Ø)	Shaft Length (L1)	Overall Length (L2)	Safety Alarm
Type I (Standard)	M14 x 1.0	7.5 mm	28.5 mm	41.0 mm	without alarm contact
Type I (Standard)	M14 x 1.5	7.5 mm	28.5 mm	41.0 mm	without alarm contact
Type I (Standard)	M16 x 1.5	7.5 mm	28.5 mm	41.0 mm	without alarm contact
Type I (Standard)	M18 x 1.5	7.5 mm	28.5 mm	41.0 mm	without alarm contact
Type I (Standard)	3/8"-18 NPT	7.5 mm	28.5 mm	41.0 mm	without alarm contact
Type II (Extended)	M14 x 1.5	13.0 mm	28.5 mm	58.7 mm	without alarm contact
Type II (Extended)	M16 x 1.5	13.0 mm	28.5 mm	58.7 mm	without alarm contact
Type II (Extended)	3/8"-18 NPT	13.0 mm	28.5 mm	58.7 mm	without alarm contact
Type III (Combination / Alarm)	M14 x 1.5	10.7 mm	41.0 mm	71.5 mm	Integrated alarm at 95°C
Type III (Combination / Alarm)	M16 x 1.5	10.7 mm	41.0 mm	71.5 mm	Integrated alarm at 107°C
Type III (Combination / Alarm)	3/8"-18 NPT	10.7 mm	41.0 mm	71.5 mm	Integrated alarm at 98°C
Type IV (U.S. Special)	1/8"-27 NPT	8.0 mm	27.0 mm	51.5 mm	without alarm contact
Type IV (U.S. Special)	1/2"-14 NPT	8.0 mm	30.0 mm	54.0 mm	without alarm contact

Parameter	Specification / Value
Manufacturer / Brand	KUS
Output Signal	Analog resistance signal (300–23 ohm characteristic curve)
Measuring range	+40°C to +120°C
Housing Material	High-quality, thermally conductive marine brass
Protection class (head)	IP67 (water- and dust-tight encapsulation)
Voltage	12 V / 24 V universal operation