1971 Evinrude 40HP outboards Service Manual, Page 27Get this manual
dTwist the hook around to grasp the "0" ring, then pull out cPush the plunger down with the straight instrumentd Pinch the "0" ring together and gently push into position with fingersWhen reassembling the fuel hose, check for cracks in the primer bulb or in the hoseThe primer bulb must be attached so that fuel flow is from the shorter to the longer hose lengthFuel flow through the primer bulb is indicated by an arrowSee Figure 3-30