Fuel Tank - Cleaning And Repair; Air Filter Housing - Removal And Installation; Idle Fuel/Air Mixture Adjustment - General Information - Yamaha TDM850 User Manual

4*6 Fuel and exhaust systems
3 Fuel tank -
cleaning and repair
1 All repairs to the fuel tank should be carried
out by a professional who has experience in this
critical and potentially dangerous work. Even
after cleaning and flushing of the fuel system,
explosive fumes can remain and ignite during
repair of the tank.
2 If the fuel tank is removed from the bike, it
should not be placed in an area where sparks or
open flames could ignite the fumes coming out of
the tank. Be especially careful inside garages
where a natural gas-type appliance is located,
because the pilot light could cause an explosion.
4 Air filter housing -
removal and installation
Removal
1 Remove the fuel tank (see Section 2).
2 Release the clamps securing the breather
hose and the drain hose to the air filter housing
and detach the hoses (see
Depending on your model, it may be easier to
detach the drain hose once the housing has been
lifted off the carburettors.
3 On TDM and XTZ models, unscrew the bolt
securing the front of the housing to the frame
(see illustrations). On all models, slacken the
clamp screws securing the housing to the
carburettor intakes (see illustration).
4 Lift the housing up off the carburettors and
remove it, on TRX models noting how the peg at
the front on the right locates in the grommet on
the frame (see illustration). On XTZ models,
draw the intake ducts apart so that they clear the
frame tube (see illustration).
Installation
5 Installation is the reverse of removal. Check
the condition of the various hoses and their
clamps and renew them if necessary.
4.3d ... which on XTZ models are
accessed from each side (arrow)
4.2 Drain hose (arrowed) - XTZ models
i
illustration).
4.3b Air filter housing bolt (arrowed) ■ XTZ
models
5 Idle fuel/air mixture
adjustment -
general information
1 Due to the increased emphasis on controlling
exhaust emissions,
regulations have been formulated which directly
affect the carburation of this machine. The pilot
screws can be adjusted, but the use of an
exhaust gas analyser
tachometer capable of accurately displaying
changes of 50 rpm is the only certain way to
adjust the idle fuel/air mixture and be sure the
machine doesn't
regulations.
2 The pilot screws are set to their correct
position by the manufacturer and should not
4.4a On TRX models, note how the peg
locates in the grommet
4.3a Air filter housing bolt (arrowed) -
be adjusted or removed unless it is necessary to
do so during a carburettor overhaul. If the screws
are to be removed, record the pilot screw's
current setting by turning the screw it in until it
seats lightly, counting the number of turns
necessary to achieve this, then fully unscrew it.
certain governmental
On installation, the screw is simply backed out
the number of turns you've recorded. Note that
for some markets, the pilot screws are sealed
with a plug to prevent tampering.
and an auxiliary
3 If the engine runs extremely rough at idle or
continually stalls, and if a carburettor overhaul
does not cure the problem, take the motorcycle
to a Yamaha dealer equipped with an exhaust
exceed the emissions
gas analyser. They will be able to properly adjust
the idle fuel/air mixture to achieve a smooth idle
and restore low speed performance.
4.4b On XTZ models, draw the ducts apart
TDM models
4.3c Slacken the clamp screws
(arrowed)...
to clear the frame
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