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e-CFR data is current as of November 24, 2020

Title 40Chapter ISubchapter CPart 90Subpart B → §90.109


Title 40: Protection of Environment
PART 90—CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS
Subpart B—Emission Standards and Certification Provisions


§90.109   Requirement of certification—closed crankcase.

(a) An engine's crankcase must be closed.

(b) For purposes of this section, “crankcase” means the housing for the crankshaft and other related internal parts.

(c) Notwithstanding paragraph (a) of this section, the Administrator will allow open crankcases for engines used exclusively to power snowthrowers based upon a manufacturer's demonstration that all applicable emission standards will be met by the engine for the combination of emissions from the crankcase, and exhaust emissions measured using the procedures in subpart E of this part. This demonstration may be made based upon best engineering judgment. Upon request of the Administrator, the manufacturer must provide an explanation of any procedure or methodology used to determine that the total CO emissions from the crankcase and the exhaust are below the applicable standard for CO.

[60 FR 34598, July 3, 1995, as amended at 61 FR 58301, Nov. 13, 1996]

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