Cub Cadet MTD 90 Series User Manual
Professional shop manual

Professional Shop Manual
78/83/90 Series Horizontal Shaft Engines
(277/357/420 cc Engines)
NOTE: These materials are for use by trained technicians who are experienced in the service and repair of outdoor power
equipment of the kind described in this publication, and are not intended for use by untrained or inexperienced individuals.
These materials are intended to provide supplemental information to assist the trained technician. Untrained or inexperi-
enced individuals should seek the assistance of an experienced and trained professional. Read, understand, and follow all
instructions and use common sense when working on power equipment. This includes the contents of the product’s Oper-
ators Manual, supplied with the equipment. No liability can be accepted for any inaccuracies or omission in this publication,
although care has been taken to make it as complete and accurate as possible at the time of publication. However, due to
the variety of outdoor power equipment and continuing product changes that occur over time, updates will be made to these
instructions from time to time. Therefore, it may be necessary to obtain the latest materials before servicing or repairing a
product. The company reserves the right to make changes at any time to this publication without prior notice and without
incurring an obligation to make such changes to previously published versions. Instructions, photographs and illustrations
used in this publication are for reference use only and may not depict actual model and component parts.
© Copyright 2010 MTD Products Inc. All Rights Reserved
Document Outline
- Chapter 1: Introduction
- Professional Service Manual Intent
- Safety
- Fasteners
- Assembly instructions
- Model and serial number
- Maintenance
- Air filter (summer engines)
- Oil type and capacity
- Changing the oil
- Fuel
- Fuel filters
- Valve lash
- Cleaning the engine
- General torque specifications
- Maintenance Chart
- Frequently used specifications
- Chapter 2: Basic Troubleshooting
- Chapter 3: Air Intake systems
- Chapter 4: The Fuel System and Governor
- Inspecting the fuel
- Test fuel for alcohol
- Fuel tank vent
- The fuel filter
- Inspect the fuel lines
- The fuel tank
- Evaporative (EVAP) emissions system
- Troubleshooting the EVAP System
- Charcoal canister
- Roll over valve
- Choke
- Primers (snow engines)
- Carburetors
- Inspecting the carburetor
- Disassembly and rebuilding of the carburetor
- Fuel shut-off valve
- Governor
- Governor arm
- Governor shaft
- Governor cup and the governor gear
- Governor adjustment
- Chapter 5: Lubrication
- Chapter 6: Starter and Charging Systems
- Chapter 7: Ignition System
- Troubleshooting the ignition system
- Stop switch
- Remote (ignition) stop switch (snow engines)
- Test for ignition that won’t turn off
- The module
- Module removal
- Installing the module and setting the air gap
- Flywheel
- About the spark plug
- Cleaning the spark plug
- Inspection of the spark plug
- Spark plug removal
- Chapter 8: Exhaust
- Chapter 9: Cylinder Head
- Chapter 10: Crankshaft, piston and Connecting Rod
- Chapter 11: Failure Analysis