Spring for machines No. 78 Ink Machines Stingray

The inner piston spring controls the reverse action of the inner piston. Like all springs it will become weaker/softer over time, if the internal piston starts to knock (a rattling sound) it could be a sign that it is too weak. To solve this problem, you can either replace it with a new one or stretch it by about 2mm. Also make sure the internal piston is lubricated and moves easily.