An exhaust manifold for a four-stroke internal combustion engine, the exhaust manifold forming at least two inlet passages and one main passage having an outlet end arranged downstream of the at least two inlet passages, wherein a first inlet passage of the at least two inlet passages connects to the main passage at a junction, wherein an intersecting wall portion between the first inlet passage and the main passage forms an upstream end portion of the junction, wherein a first portion of the first inlet passage at the intersecting wall portion has a first inlet passage cross sectional area, wherein the first inlet passage cross sectional area is smaller than a second inlet passage cross sectional area of a second portion of the first inlet passage located upstream of the first portion of the first inlet passage, and whereby the cross sectional area of a passage portion is calculated based on the hydraulic diameter of the relevant cross sectional area, wherein the first inlet passage is connected to the main passage downstream of a second inlet passage of the at least two inlet passages, wherein the main passage comprises a first main passage portion at the intersecting wall portion, the first main passage portion having a first main passage cross sectional area, and wherein the first main passage cross sectional area is smaller than a second main passage cross sectional area of a second main passage portion of the main passage located upstream of the junction, characterised in that the main passage comprises a widening section extending at least upstream of the first main passage portion, which widening section widens the main passage in a first direction, the first direction extending in a first cross sectional plane, which first cross sectional plane extends through the first inlet passage, through at least a portion of the main passage, extends along the main passage axis, and includes the main passage axis, and wherein the first direction is directed away from the first inlet passage. wherein a first inlet passage of the at least two inlet passages connects to the main passage at a junction, wherein an intersecting wall portion between the first inlet passage and the main passage forms an upstream end portion of the junction, wherein a first portion of the first inlet passage at the intersecting wall portion has a first inlet passage cross sectional area, wherein the first inlet passage cross sectional area is smaller than a second inlet passage cross sectional area of a second portion of the first inlet passage located upstream of the first portion of the first inlet passage, and whereby the cross sectional area of a passage portion is calculated based on the hydraulic diameter of the relevant cross sectional area, wherein the first inlet passage is connected to the main passage downstream of a second inlet passage of the at least two inlet passages, wherein the main passage comprises a first main passage portion at the intersecting wall portion, the first main passage portion having a first main passage cross sectional area, and wherein the first main passage cross sectional area is smaller than a second main passage cross sectional area of a second main passage portion of the main passage located upstream of the junction, characterised in that the main passage comprises a widening section extending at least upstream of the first main passage portion, which widening section widens the main passage in a first direction, the first direction extending in a first cross sectional plane, which first cross sectional plane extends through the first inlet passage, through at least a portion of the main passage, extends along the main passage axis, and includes the main passage axis, and wherein the first direction is directed away from the first inlet passage.