You didn't mention if there were any other issues. Thereby I'll take a shot. With the info you provided... it being a '94 model, my 1st question would be how many miles are on the engine. If the compression is low IE worn rings, with each explosion of the power stroke it's creating more pressure that may be getting by the rings, thereby presurizing the crankcase area & pushing more oil vapor out your head breather...
Another more simple thing to check would be the condition of the air filter. If its restricted too much it can cause more of a vaccum in the crankcase area.