40 CFR 90.128 - Installation instructions.
(a) If you sell an engine for someone else to install in a piece of nonroad equipment, give the engine installer instructions for installing it consistent with the requirements of this part. Include all information necessary to ensure that an engine will be installed in its certified configuration. In particular, describe the steps needed to control evaporative emissions, as described in § 90.127. This may include information related to the delayed requirements for small-volume equipment manufacturers.
(b) You do not need installation instructions for engines you install in your own equipment.
(c) Provide instructions in writing or in an equivalent format. For example, you may post instructions on a publicly available Web site for downloading or printing. If you do not provide the instructions in writing, explain in your application for certification how you will ensure that each installer is informed of the installation requirements.