Sierra 18-3668 Thermostat Kit for Mercruiser Outboards (61°C)

Sierra Marine 142°F (61.1°C) thermostat kit 18-3668 will replace the following thermostats:

- Mercury/Mercruiser 807252T4 & 807252Q4

- Sierra 18-3668D

- Mallory 9-43150

Thermostat Kit Contents:

- 18-3551 Thermostat (59137)

- 18-2552 Thermostat Cover Gasket (27-33179-2)

- 18-2553 Thermostat Cover Gasket (27-47510)

- 18-2554 Thermostat Cover Gasket (27-41812)

- 18-7173 O-Ring (25-30224)

- 18-2917 Thermostat Housing Gasket (27-53045-1 & 27-3391)

The thermostat, gaskets and O-ring are suitable for the following engines:

Mercruiser:

- 175/4.3L, 4.3LX (262 CID) Old & New Designs (B527955 & Up)

- 185 (229 CID) (6330183 - 6919655)

- 185 (262 CID) (A331455 - B527954)

- 200 GM (6218462 - B525981)

- 200/5.0L GM (Old Design) (B525982 & Up)

- 205 (262 CID) (A331455 - B527954)

- 205/4.3L, 4.3LX (262 CID) Old & New Designs (B527955 - D714369)

- 225 GM (2278647 - 2399197)

- 228 GM (6218462 - B525981)

- 230 GM (6218462 - B525981)

- 230 GM IB with Standard Cooling (5907058 - B522505)

- 230/5.0L GM IB with Standard Cooling (B522506 - B525981)

- 230/5.0L-LX GM Old & New Designs (B525982 - F600999, B525982 & Up)

- 260 GM (6218462 - B525981)

- 260 GM IB with Standard Cooling (5907058 - B522505)

- 260/5.7L GM IB with Standard Cooling (B522506 - B525981)

- 260/5.7L GM IB with Standard Cooling (B522506 - B525981)

- 260/5.7L GM Old & New Designs (B525982 - F600999)

- 350 Mag (B525982 - F600999)

- 5.7 GM Ski (A338553 - B514626)

- 5.7 GM Ski/Bravo Old & New Designs (B514627 & Up)

- 300 MR/TRS GM (6668677 - B430367)

- 325 GM (2278747 - 2313964)

- 330 GM with BorgWarner & Standard Cooling (6083145 & Up)

- 340/7.4L GM IB with Standard Cooling (5889914 & Up)

- 7.4 Bravo GM Old & New Designs (B771113 - D603117, B771113 & Up)

- 7.4L with Hurth IB with Standard Cooling (C391564 - D715493)

- 350 GM Magnum (A635178 - B525981)

- 350 GM Magnum Old & New Designs (B525982 & Up)

- 370 TRS GM (6721528 & Up)

- 454 GM Magnum/Alpha (Old Design) (A631894 - B785148)

- 454 GM Magnum/Bravo (New Design) (A631894 & Up)

- 898 GM (6218462 & Up)