Mercury 75 Service Manual

3B-0 - FUEL SYSTEM 90-830234R3 DECEMBER 1997
Table of Contents
Page
Specifications 3B-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WME Carburetor Chart 3B-1. . . . . . . . . . . . . . . . . . . . . . . .
Special Tools 3B-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Carburetor (WME–29/30/31/41/46/47/48/49) 3B-4. . . . .
Carburetor (WME–59/60/61/62/75/76/77/78/82/83) 3B-6
Carburetor–WME-32/32A/33/34/40/40A 3B-10. . . . . . . .
Carburetor–WME-50/51/52/79/80/81 3B-12. . . . . . . . . . .
Fuel System (Linkage) 3B-16. . . . . . . . . . . . . . . . . . . .
Adjustments 3B-17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Idle Mixture Screw Adjustment 3B-17. . . . . . . . . . . . .
Idle Speed Adjustment 3B-17. . . . . . . . . . . . . . . . . . . .
Float Adjustment 3B-17. . . . . . . . . . . . . . . . . . . . . . . . .
Main (High Speed) Jet Adjustment 3B-18. . . . . . . . . .
Jet Orifice Size Chart 3B-18. . . . . . . . . . . . . . . . . . . . .
High Altitude Jet Chart 3B-19. . . . . . . . . . . . . . . . . . . .
Fuel System Troubleshooting 3B-20. . . . . . . . . . . . . . . . .
General Information 3B-20. . . . . . . . . . . . . . . . . . . . . .
Problem: Engine Floods 3B-20. . . . . . . . . . . . . . . . . . .
Problem: Engine Runs Too Rich 3B-20. . . . . . . . . . . .
Problem: Fuel Blow Back Out Of Carburetor 3B-20.
Problem: Rough Idle 3B-20. . . . . . . . . . . . . . . . . . . . . .
Problem: Engine Turns Over But Will Not Start
Or Starts Hard When Cold 3B-21. . . . . . . . . . . . . . . . .
Problem: Unable to Reduce Engine RPM to Slow
Idle 3B-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Problem: Engine Runs Too Lean 3B-22. . . . . . . . . . .
Problems:
-Engine Idles Rough And Stalls
-Engine Runs Uneven Or Surges
-Engine Will Not Accelerate 3B-22. . . . . . . . . . . . . . . .
Inspection 3B-23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enrichener System 3B-24. . . . . . . . . . . . . . . . . . . . . . . . . .
Description for Three Cylinder Engines 3B-24. . . . . .
Enrichener Valve Hose Installation
- Three Cylinder Engines 3B-24. . . . . . . . . . . . . . . . . .
Description for Four Cylinder Engines 3B-24. . . . . . .
Enrichener Valve Hose Installation
- Four Cylinder Engines 3B-24. . . . . . . . . . . . . . . . . . .
Acceleration Pump Circuit Operation
- Four Cylinder Engines 3B-26. . . . . . . . . . . . . . . . . . .
Acceleration Pump Fuel Flow Circuit for
Four Cylinder Engines 3B-27. . . . . . . . . . . . . . . . . . . .

Mercury 75 Specifications

General

Horsepower	75 hp
Starting	Electric
Cylinders	3
Warranty	3 years
Shaft Length	20 in. or 25 in.