www.marinedieseldirect.com is part of the TOAD Marine Supply. Order parts from this catalog online, by phone 616-820-0022, fax 616-396-1136 or email

General Information
Preparations For Starting
Before Starting
Starting Engine
Engine Break-in and General Running
Stopping the Engine
Decompression Lever
Instrument Panel
Wiring Diagram
Preparing Engine for Storage
Preparing Engine for Spring Service
Fuel Injection Timing
Diesel Valve Timing
Adjusting Fuel Timing
Decompression Device Adjustment
Fuel System
Fuel Bleeding
Oil Filter Change
Sea Water Pump and Impeller Replacement
Model 15 Sea Water Circulation Diagram
Model 12, 18, 20, 25, 25XP, 30, 40 & 50 Water
Fresh Water Circulation Diagram

Hurth Transmission
Periodic Service Chart for Engine
Marine Engine Warranty - Limited

Engine Specifications and Images
(by engine model)



Fresh Water Circulation Diagram
All Models Except M-15
Normal Range 165 to 195 F

Sea Water:

1. Sea water enters through sea water inlet

2. Through sea water valve when open

3. Through sea water pump into heat exchanger to cool fresh water system

4. From heat exchanger to sea water overboard through exhaust port

Fresh Water:

1. Coolant (fresh water with antifreeze) is introduced into the system from the coolant section of exhaust manifold by removing pressure cap and filling manifold tank within one inch of lower rim of fill port.

2. Fresh water engine driven circulating pump moves coolant from heat exchanger through engine block circulating pump and thermostat back through exhaust manifold into heat exchanger to be cooled.

The manifold serves as the engine expansion tank to allow for expansion of coolant as it is heated.  You also fill the system at this point.  In some cases when hot water heaters are installed an expansion or surge tank may be required to prevent air from entering the system.

Should your engine overheat, first check coolant level to make sure it is not low which would cause air locks to develop.  If air does enter the system, it may require a couple of fillings to remove the air pocket.   A momentary increase of engine RPM to approximately 2800 to 3000 RPM may aid in moving the air from the system.  In some cases it may require doing this 2 or 3 times.  Do this just as you notice the temperature starting to rise above normal.