Sierra Throttle Position Sensor 18-7700 for 350 V-8 and 377 V-8 Marine Engines

The Sierra 18-7700 is a throttle position sensor built for a specific set of marine V-8 engine applications. The throttle position sensor monitors the position of the throttle plate and sends that signal to the engine management system, which uses it to control fuel delivery and ignition timing as the throttle is opened and closed. Keeping this sensor within factory specification is important for smooth throttle response, stable idle, and consistent acceleration.

The Sierra 18-7700 is designated for use on the Black Scorpion SKI 350 V-8 engine across three serial number ranges (model years 1996, 1997, and 1998), the 377 MAG 377 V-8 (2008-2010, serial A300000 and up), the 377 Scorpion SKI 377 V-8 (1997-1998, serial range K000656-L600314), and the MX 6.2L MPI 377 V-8 engine across three additional serial number ranges spanning 2002 through 2007. Because engine applications are broken out by serial number rather than model year alone, confirming the serial number on the engine tag against the ranges listed below is the reliable way to verify fit before ordering.

The sensor weighs 0.1 pounds and carries UPC 808282287269 for accurate identification when ordering or cross-checking inventory.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-7700
• Product Type: Throttle Position Sensor
• UPC: 808282287269
• Weight: 0.1 pounds

Fitment

• Black Scorpion SKI 350 V-8, 1996, serial F350583-K040000
• Black Scorpion SKI 350 V-8, 1997, serial K040001-L002699
• Black Scorpion SKI 350 V-8, 1998, serial L002700-L005600
• 377 MAG 377 V-8, 2008-2010, serial A300000 & up
• 377 Scorpion SKI 377 V-8, 1997-1998, serial K000656-L600314
• MX 6.2L MPI 6.2L 377 V-8, 2002-2004, serial M300000-W059999
• MX 6.2L MPI 6.2L 377 V-8, 2004-2007, serial W060000-A064824
• MX 6.2L MPI 6.2L 377 V-8, 2007, serial A064825-A299999

Replaces (OEM)

• No OEM cross-reference numbers are listed for this part number.

Frequently Asked Questions

What engines does the Sierra 18-7700 throttle position sensor fit? The Sierra 18-7700 fits the Black Scorpion SKI 350 V-8, the 377 MAG 377 V-8, the 377 Scorpion SKI 377 V-8, and the MX 6.2L MPI 377 V-8, each within specific serial number ranges.

Will the 18-7700 fit a 1998 Black Scorpion SKI 350 V-8? Yes, for a 1998 Black Scorpion SKI 350 V-8 engine in the serial number range L002700-L005600, the 18-7700 is the correct throttle position sensor.

Does the 18-7700 work on the MX 6.2L MPI 377 V-8? It does, across three serial number windows: M300000-W059999, W060000-A064824, and A064825-A299999, covering 2002 through 2007 production.

What is the weight of the Sierra 18-7700 throttle position sensor? This throttle position sensor weighs 0.1 pounds.

Is the Sierra 18-7700 an OEM part or an aftermarket replacement? Sierra 18-7700 is a Sierra-branded throttle position sensor built to the fitment specifications listed for its covered engine applications.

Does the 18-7700 fit a 1996 Black Scorpion SKI engine? Yes, the 1996 Black Scorpion SKI 350 V-8 in serial range F350583-K040000 is a listed application for the 18-7700 sensor.

What serial number range applies to the 377 MAG application? For the 377 MAG 377 V-8, the 18-7700 applies to engines with serial number A300000 and up, covering 2008-2010.

Does the 18-7700 fit the 377 Scorpion SKI engine? Yes, on the 377 Scorpion SKI 377 V-8, the 18-7700 covers the 1997-1998 serial number range K000656-L600314.

What is the UPC for this throttle position sensor? The UPC for the Sierra 18-7700 throttle position sensor is 808282287269.

How do I confirm my engine matches the listed fitment for the 18-7700? Since the 18-7700 fitment is broken out by serial number rather than model year alone, check the engine's serial number tag against the specific ranges listed for the Black Scorpion SKI, 377 MAG, 377 Scorpion SKI, or MX 6.2L MPI applications.

What does a throttle position sensor like the 18-7700 do? A throttle position sensor tracks the angle of the throttle plate and reports it to the engine's fuel and ignition management system, which the 18-7700 is built to do on its listed V-8 marine engine applications.

Are there other Sierra part numbers associated with the same engines as the 18-7700? Yes, the engine applications that use the 18-7700 also reference other Sierra part numbers such as 18-7697, 18-7701, and 18-7684 for different components on the same engine.