11.5
500 EFI INTERNATIONAL / QUADRICYCLE
11
500 EFI QUADRICYCLE EMISSIONS SYSTEM
Overview
500 EFI Quadricycle model ATVs are equipped with an emissions system from the factory. The emission system is designed to meet
the various international emissions standards.
The emissions system consists of:
• A. Air Valve Filter
• B. Air Valve Assembly (one way operation)
• C. Tubing
• D. Air Injection Tube
• E. Catalyst
The emissions system utilizes an air valve filter (A), one-way air valve system (B), and vacuum to help reduce emissions. The air
valve assembly (B) contains a vacuum shutoff. When engine RPM drops quickly or is at high RPM, the air valve closes. During
idle through mid-range RPM the air valve is open and air is drawn into the from the PVT intake duct. The air valve assembly (B)
opens and closes based on the vacuum pressure connected to the air duct.
The exhaust pipe creates a vacuum after each engine exhaust pulse. The air valve (B) opens and closes based on this engine pulse.
Fresh air then travels through the air injection tubes (C and D) and into the exhaust. This air (oxygen) enters the exhaust pipe and
mixes with the exhaust gases from the engine, reducing emissions. The air and exhaust gas mixture then passes through the silencer
(E), which contains a catalyst. This catalyst also reduces emissions by interacting with the exhaust as it passes through the silencer.
NOTE: No maintenance or service of the catalyst is required.
A
B
D
Air Flow
E
C