Evaporative Emissions Control System - Buell 2002 P3 Service Manual

HOME

EVAPORATIVE EMISSIONS CONTROL SYSTEM

GENERAL
Buell motorcycles sold in the state of California are equipped
with an evaporative (EVAP) emissions control system. In con-
formance with California Air Resource Board (CARB) regula-
tions, the EVAP system prevents both fuel and crankcase
vapors from escaping into the atmosphere. See
The EVAP system functions as follows:
●
The fuel vapor vent tube connected to the fitting at the
front of the fuel cap flange allows fuel vapors in the fuel
tank to be vented through the rollover valve to the char-
coal canister. If the vehicle is tipped, the rollover valve
also prevents the loss of gasoline through the vent tube.
●
When the engine is running, negative pressure (vacuum)
created at the carburetor venturi draws the fuel vapors
stored in the charcoal canister through the purge hose
to the carburetor where they are burned as part of the
normal combustion process.
●
Fuel vapors emanating from the carburetor throat are
drawn to the charcoal canister through a fitting on the
PCV outlet hose. A preformed hose on one end of the
3-Way
Fitting
Fuel
Vapors
3-Way
Fitting
3-Way
Fitting
Breather
Drain Hose
Figure 4-25. California Evaporative Emissions Control System Schematic
Figure 4-25.
PCV
Valve
Fuel
Line
Crankcase
Vapors
Carburetor
Venturi
Ring
PCV
Outlet Hose
fitting is fixed to an allen head screw on the venturi ring
for positive location.
●
Crankcase vapors passing through the PCV valve follow
the fuel vapors to the charcoal canister via a 3-way fitting
plumbed into the PCV outlet hose. The fuel and crank-
case vapors, after passing through the charcoal canister,
travel through the purge hose to the carburetor, and like
the vapors from the fuel tank, are burned during combus-
tion.
11 1
Verify that the vent tubes and hoses do not contact hot
exhaust or engine parts. Tubes contain flammable vapors
that can be ignited if damaged, possibly causing fire or
explosion, which could result in death or serious injury.
The EVAP system has been designed to operate with a mini-
mum of maintenance. Check that all hoses are correctly
routed and properly connected. Also, verify that the hoses are
not pinched or kinked.
Vent Tube
Fitting
Rollover
Valve
Fuel
Valve
Purge
Tube
Vent
Tube
Fuel
Vapors
"Carb"
"Tank"
Charcoal
Canister
2002 Buell P3: Fuel System
4.7
WARNING WARNING
NOTE
Fuel
Tank
a0187a4x
4-27