Not sure what you mean by metering rod - is that the main jet adjust? If yes you can a rebuild kit that includes it for about 8-10 dollars.
If you look around the net suppliers you can probably find someone with old stock of that carb for 40-50 dollars. The 521 had a long run and broken engines for them very available for very little, even free. That style engine was used for years by many other manfs so lots of broken ones around.
I picked up a machine with one of the new no-jet carbs and am no so fond of it.
trouts2
This message was modified Sep 9, 2008 by trouts2