[Code of Federal Regulations]
[Title 40, Volume 30]
[Revised as of July 1, 2004]
From the U.S. Government Printing Office via GPO Access
[CITE: 40CFR1051.615]

[Page 634-635]
 
                   TITLE 40--PROTECTION OF ENVIRONMENT
 
         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
 
PART 1051_CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES
--Table of Contents
 
                     Subpart G_Compliance Provisions
 
Sec. 1051.615  What are the special provisions for certifying small 
recreational engines?

    (a) You may certify ATVs with engines that have total displacement 
of less than 100 cc to the following emission exhaust standards instead 
of certifying them to the exhaust emission standards of subpart B of 
this part:
    (1) 25.0 g/kW-hr HC+NOX, with an FEL cap of 40.0 g/kW-hr 
HC+NOX.
    (2) 500 g/kW-hr CO.
    (b) You may certify off-highway motorcycles with engines that have 
total displacement of 70 cc or less to the following emission exhaust 
standards instead of certifying them to the exhaust emission standards 
of subpart B of this part:
    (1) 16.1 g/kW-hr HC+NOX, with an FEL cap of 32.2 g/kW-hr 
HC+NOX.
    (2) 519 g/kW-hr CO.
    (c) You may use the averaging, banking, and trading provisions of 
subpart H of this part to show compliance with this HC+NOX 
standards (an engine family meets emission standards even if its family 
emission limit is higher than the standard, as long as you show that the 
whole averaging set of applicable engine families meet the applicable 
emission standards using emission credits, and the vehicles within the 
family meet the family emission limit). You may not use averaging to 
meet the CO standards of this section.
    (d) Measure emissions by testing the engine on a dynamometer with 
the steady-state duty cycle described in Table 1 of this section.
    (1) During idle mode, hold the speed within your specifications, 
keep the throttle fully closed, and keep engine torque under 5 percent 
of the peak torque value at maximum test speed.
    (2) For the full-load operating mode, operate the engine at wide-
open throttle.
    (3) See part 1065 of this chapter for detailed specifications of 
tolerances and calculations.
    (4) Table 1 follows:

[[Page 635]]



                     Table 1 of Sec. 1051.615--6-Mode Duty Cycle for Recreational Engines
----------------------------------------------------------------------------------------------------------------
                                                                      Torque
                                                   Engine speed     (percent of    Minimum time
                                                    (percent of    maximum test       in mode        Weighting
                                                   maximum test   torque at test     (minutes)        factors
                                                      speed)          speed)
----------------------------------------------------------------------------------------------------------------
Mode number:
    1...........................................              85             100             5.0            0.09
-------------------------------------------------
    2...........................................              85              75             5.0            0.20
-------------------------------------------------
    3...........................................              85              50             5.0            0.29
-------------------------------------------------
    4...........................................              85              25             5.0            0.30
-------------------------------------------------
    5...........................................              85              10             5.0            0.07
-------------------------------------------------
    6...........................................            Idle               0             5.0            0.05
----------------------------------------------------------------------------------------------------------------

    (e) All other requirements and prohibitions of this part apply to 
these engines and vehicles.