Ed:

In the Perry type carb the o-rings are supposed to take a set, and almost lock themselves in place.

Many o-rings that will fit and resist the alcohol fuels will not exhibit this self locking. For best results use only the manufacturer supplied parts.

You can get them from Horizon as stated, and also fron Conley Precision (Maker of Perry carbs and pumps) and from MECoA, as used in the K&B version of the Perry.

Bill.