[Voxel]

Ok theres no need for a timer here, simply make a stock for the clearchat and then send the message.

pawn Код:

public OnPlayerConnect(playerid)
{
    ClearChat(playerid); //clear the chat first
    SendClientMessage(playerid, -1, "Welcome to latvia stunt server!"); //then send the message
    return 1;
}

stock ClearChat(playerid)
{
    for(new i = 0; i < 50; i++) SendClientMessage(playerid, -1," ");
    return 1;
}

Try to use as less timers as possible in your script, good luck !