What is the name of the part that looks like a pump. There is one on the oil line and one on the top of the jet drive. Looks like a pump you can push it in and it will flex back out. Made of flimsy plactic could be a diaphram of sorts but was wondering what it is called and what it is used for. Looks like it could be used to push air or something. It is on a 96 770 Tigershark
