Toro Reelmaster 5510 Series, Service Manual

Page: 102 / 662

To meet gasoline engine emission requirements, the Kubota gasoline engine
used on your Reelmaster has a catalytic muffler. In addition to providing sound
damping and spark arresting, the muffler also includes a three way catalyst to
treat the exhaust gases which are created from the combustion process. The
3-way catalyst consists of a honeycomb core coated with a mixture of precious
metals. The hot exhaust gases flow through the catalyst where oxidation and
reduction reactions take place. These chemical reactions reduce the amount
of CO, HC, and NOx in the exhaust. Two oxygen sensors are included in the
exhaust system and are used as inputs for the engine ECU to monitor exhaust
system operation. The exhaust exits the catalytic muffler through the tailpipe
outlet.
Removing the Exhaust System
CAUTION
The muffler and exhaust pipe may be hot. To avoid possible burns,
allow the engine and exhaust system to cool before working on the
exhaust system.
1. Park machine on a level surface, lower cutting units, stop engine, engage
parking brake and remove key from the key switch. Raise and support hood.
2. Raise and support hood to gain access to exhaust system. Allow engine and
exhaust system to cool before doing any disassembly of exhaust system
components.
3. Remove exhaust system components from the engine as necessary. Discard
all removed gaskets (items 13, 17, and/or 20 in Figure 45 ).
Installing the Exhaust System
Note: Ensure that all exhaust system flanges and sealing surfaces are free of
debris or damage that may prevent a tight seal.
1. Ensure to install new gaskets in place of all gaskets that were removed. Do
not use any type of gasket sealant on gasket or flange surfaces.
2. Assemble all removed exhaust system components ( Figure 45 ).
A. If exhaust manifold (item 18 in Figure 45 ) was removed from engine
exhaust manifold, install new exhaust manifold gasket so that raised
ridge side of gasket is mated to the exhaust manifold on the engine.
B. During exhaust system installation, finger tighten all exhaust system
components before fully tightening any of the fasteners. When tightening
fasteners, secure exhaust manifold (item 18 in
Figure 45 ) to muffler first
and then tighten nuts that secure exhaust manifold to engine exhaust
manifold. Once these connections are secure, tighten fasteners for
exhaust outlet and exhaust mount. Finally, secure lower heat shields
and upper heat shield.
C. If oxygen sensors (item 21 in Figure 45 ) were removed, torque the
sensors to 41 to 59 N∙m (30 to 44 ft-lb) . Plug sensor connectors into
engine harness after installation.
D. Adjust muffler guard (item 26 in Figure 45 ) so that there is 9.5 mm (3/8
inch) clearance between exhaust outlet and guard in all directions.
Kubota Gasoline Engine: Service and Repairs Page 5–10 Reelmaster ® 5410/5510/5610 Series
15216SL Rev C