I believe the 484 had its valve cages replaced on its last major shopping a few years back. In the nineties 484 was a very square engine and would run higher than all of the rest.
One or the other valve cages port locations are either improperly located or the whole cage is in the wrong position.
The beauty of a steam locomotive is that it can be repaired when time and money permit.
For example the 488 used to be HORRIBLY timed in the early 90's and now it sounds quite good. Steam locomotives are a continual work in progress . There are always things to repair or adjust no matter how right it is with the world the day it rolls out of the shop.
It has always amazed me that with a certain level of issues a Steam Locomotive's can still go out and get the job done. I know that given who the President is now as time permits it will be corrected. 463 is a shining example of what a locomotive "should" sound like.
Edited 2 time(s). Last edit at 11/01/2014 09:00AM by christopher king.