hi , new here and happy to be part of this . i have a problem with an 86 hilux which had a 3y engine that was changed out for a 4y . bought new motor , no manifolds etc , and put back all from 3y . eventually bought new carb (no.21100-75030) which started the vehicle but would not accelerate . discovered that new carb's bores are bigger , is this because of wrong manifold or just wrong carb. ?? thanks .