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WaterMota Pressure Relief Valves

Made in the United Kingdom

WaterMota Pressure Relief valve kit for the WaterMota Pre-Crossflow and Crossflow petrol engines, including the pressure relief spring, ball, new hose and hose clips.

WaterMota Sea Wolf Pressure Relief Valve

By WaterMota : W1749A
Part #: W1749A
Availability: In Stock

WaterMota Sea Tiger/Leopard Pressure Relief Valve

By WaterMota : W1749B
Part #: W1749B
Availability: In Stock

WaterMota Pressure Relief Valves

The WaterMota Pressure Relief Valve consists of the replacement parts for the water cooling pressure relief system as fitted to WaterMota engines with a Thermostat. The kit contains all the parts to replace a worn out or corroded thermostat bypass valve.

The pressure relief valve on the waterMota petrol engines is a very simple device, however, it is critical if you have a thermostat. It allows water to escape from the engine while the thermostat is closed. Water from the engine water pump is continually being pumped to the engine, however, while the thermostat is closed this water has nowhere to go, it, therefore, forces the pressure relief valve open and allows the water to escape out of the exhaust.

Fitting The WaterMota Pressure Relief Valve

The pressure relief valve sits between the thermostat housing on the top of the engine block and the water inlet on the engine block. It is fitted between two WaterMota Pipe Connector (which are not included in this kit). Remove the old hose, relief spring and ball and replace them with the new kit, the pressure relief ball goes at the bottom and the pressure relief spring sits on top.

If you are fitting a thermostat for the first time, you must also fit this pressure relief thermostat bypass valve, you will require 2 x WaterMota Pipe Connector to fit into the thermostat housing and the water inlet.

Which WaterMota engine is this suitable for?

The WaterMota pressure relief valve is suitable for the majority of WaterMota petrol engines including the WaterMota Sea Wolf Mk1 & Mk2 and WaterMota Sea Tiger Mk1 & Mk2 as long as they have a thermostat fitted.


  W1749A W1749B
Compatible with WaterMota Sea Wolf Mk1 & Mk2 WaterMota Sea Tiger Mk1 & Mk2
Engine Type Pre-Crossflow & Crossflow Pre-Crossflow & Crossflow
Contains Relief Spring W1760 for WaterMota Sea Wolf W1761 for WaterMota Sea Tiger

What's Included

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