Thermostat Kit - Mercury 90 HP 3 Cylinder (1987-2004) OEM# 18-3569 | WSM 780-200

Thermostat Kit Mercury 90 Hp 3 Cylinder 87-04 OEM# 18-3569

This WSM thermostat kit is a quality aftermarket replacement part designed for Mercury 3 Cyl 3.375 Bore Looper 90 and 1 other compatible model.

It replaces selected OEM reference numbers including 18-3569, 803061T1 and is suitable for service, repair and rebuild work.

Key Features

• Quality aftermarket replacement part from WSM
• Engineered for dependable fit, function and service life
• Designed for marine and powersports repair and maintenance
• Compatible with 18 listed fitments
• Replaces selected OEM reference numbers listed below

Product Details

• Brand: WSM
• WSM Part Number: 780-200
• Product: Thermostat Kit
• OEM Reference: 18-3569, 803061T1
• Application: Mercury 3 Cyl 3.375 Bore Looper 90 and 1 other compatible model

Product Fitment

This part is suitable for the following models:

• Mercury 3 Cyl 3.375 Bore Looper 90 – 1987
• Mercury 3 Cyl 3.375 Bore Looper 90 – 1988
• Mercury 3 Cyl 3.375 Bore Looper 90 – 1989
• Mercury 3 Cyl 3.375 Bore Looper 90 – 1990
• Mercury 3 Cyl 3.375 Bore Looper 90 – 1991
• Mercury 3 Cyl 3.375 Bore Looper 90 – 1992
• Mercury 3 Cyl 3.375 Bore Looper 90 – 1993
• Mercury 3 Cyl 3.500 Bore Looper 90 – 1994
• Mercury 3 Cyl 3.500 Bore Looper 90 – 1995
• Mercury 3 Cyl 3.500 Bore Looper 90 – 1996
• Mercury 3 Cyl 3.500 Bore Looper 90 – 1997
• Mercury 3 Cyl 3.500 Bore Looper 90 – 1998
• Mercury 3 Cyl 3.500 Bore Looper 90 – 1999
• Mercury 3 Cyl 3.500 Bore Looper 90 – 2000
• Mercury 3 Cyl 3.500 Bore Looper 90 – 2001
• Mercury 3 Cyl 3.500 Bore Looper 90 – 2002
• Mercury 3 Cyl 3.500 Bore Looper 90 – 2003
• Mercury 3 Cyl 3.500 Bore Looper 90 – 2004

Why Buy WSM

WSM is a trusted manufacturer of aftermarket marine and powersports parts, known for dependable quality, strong fitment coverage and workshop-ready replacement components.

You May Also Need

Browse related parts for compatible models:

• Bearing Needles With Washers Mercury / Mariner 70 - 125 / 200 - 300 Hp OEM# 29-88258 – 010-120-34
• Oil Block Off Plate Mercury / Sea-Doo 580 / 650 / 720 89-05 – 011-212
• Water Pump Kit Complete Force / Mercury / Mariner / Mercruiser 30 - 300 Hp OEM# 18-3570 – 750-155
• Water Pump Kit Complete Force / Mercury / Mariner 30 - 125 Hp OEM# 43026T9 – 750-156

Please use the fitment guide, OEM references and images to confirm this is the correct part before ordering.