Will a Pokemon with a macho brace and pokerus gain 4X the EV's in gen III ?

Question

I heard that pokerus doesnt double ev training items until gen iv, is this true? If so, does that mean you can only get 2X the ev's at most in gen III?

Answer 1

'A new held item, the Macho Brace, doubles the effort points gained in battle. In combination with the Pokérus, a Pokémon can gain four times the normal effort points. However, the effects of the item do not transfer to a Pokémon holding an Exp. Share. '

Bulbapedia obviously thinks 4x works. So I suppose it does
http://bulbapedia.bulbagarden.net/wiki/Effort_values

Answer 2

The stronger EV-enhancing item Power Brace wasn't introduced until Gen IV, so if your trying to get the best EV-enhancing in IV Gen then I suggest that. If pokerus doesn't double the EV items until Gen IV, then yes. 2X is the most in gen three. I cant find anything about Pokerus doubling EV items in Third Gen

Gen lll
1*2(MchBrc)=2

Until IV
1 2(MchBrc) = 2 2(Pkrs) = 4
1 + 4(PwrBrcr) = 5 * 2(Pkrs) = 10

Hope I helped somehow,

Answer 3

The Macho Brace, doubles the effort points gained in battle. In combination with the Pokérus, a Pokémon can gain four times the normal effort points.

And if you have another Pokemon holding an ex-share then, the effects
of the item will not transfer to a Pokémon holding an Exp. Share.

source :: bulbapedia