Merc v6 2.5 Head Fitment?

[Superjetjim]

Does anyone know what this fitting in the head is for (the one with a pipe attached that runs back to all three carbs ?


Also should a pipe be attached to the other outlet shown? I am speculating it's some form of enricher that opens once the more warms up - is that correct?

Cheers

Jim

[TWIN RIG]

Its the thermal air valve

[Superjetjim]

Thanks Twin