142 Degree Thermostat KIT Original Equipment Mercury
( Old Style )
142 degree thermostat kit fits many different models of Mercruiser raw water cooled marine engines.
18-3551 - 142 degree thermostat
18-2552 cover gasket
18-2553 cover gasket
18-2554 cover gasket
18-7173 O-Ring and the 18-2917 housing gasket
- Replaces Mercury 807252Q4, 807252T4
- Replaces Mallory 9-43150
- 1981 And Up Standard Cooling with cast iron housing
- Not for EFI engines!
5.7L GM IB, Beginning # B522506 - Ending # B525981
- 5.7 GM Ski, Beginning # A338553 - Ending # B514626
- Mercruiser T-stat # 59137
Make sure to use the Mercruiser style thermostat and not an automotive style.
If you use an automotive style it will cause the engine to run very cool on the gauge but your exhaust manifold's will be very hot!