---
kind: "section"
citation: "30 C.F.R. § 7.84"
title: "30"
number: "7.84"
heading: "Technical requirements."
url: "https://uscodex.org/cfr/30/7.84"
---

# §7.84. Technical requirements.

- (a) **Fuel injection adjustment.** The fuel injection system of the engine shall be constructed so that the quantity of fuel injected can be controlled at a desired maximum value. This adjustment shall be changeable only after breaking a seal or by altering the design.
- (b) **Maximum fuel-air ratio.** At the maximum fuel-air ratio determined by [§ 7.87](/cfr/30/7.87.md) of this part, the concentrations (by volume, dry basis) of carbon monoxide (CO) and oxides of nitrogen (NOX) in the undiluted exhaust gas shall not exceed the following:
  - (1) There shall be no more than 0.30 percent CO and no more than 0.20 percent NOX for category A engines.
  - (2) There shall be no more than 0.25 percent CO and no more than 0.20 percent NOX for category B engines.
- (c) **Gaseous emissions ventilation rate.** Ventilation rates necessary to dilute gaseous exhaust emissions to the following values shall be determined under [§ 7.88](/cfr/30/7.88.md) of this part:
- (d) **Fuel deration.** The fuel rates specified in the fuel deration chart shall be based on the tests conducted under paragraphs [(b)](#b) and [(c)](#c) of this section and shall ensure that the maximum fuel:air (f/a) ratio determined under [paragraph (b)](#b) of this section is not exceeded at the altitudes specified in the fuel deration chart.
- (e) **Particulate index.** For each rated speed and horsepower requested, the particulate index necessary to dilute the exhaust particulate emissions to 1 mg/m 3 shall be determined under [§ 7.89](/cfr/30/7.89.md) of this part.

## Notes

### Source

Source: 61 FR 55504, Oct. 25, 1996, unless otherwise noted.

### Authority

Authority: 30 U.S.C. 957.

### Source

Source: 53 FR 23500, June 22, 1988, unless otherwise noted.