Re: '89 50hp Force Irratic idle and bad skip until runnig full throttle
How much preload should the spring have on it after installation? Should the spring hold the float open when the carb is inverted?
No, when inverted the float should close the needle port. And the float should be level with the body. Preloading is very little maybe no more than half or one turn. I'll start with half turn and test by placing the carb right side up. Using the tip of your finger, raise the float and it should come down without any hesitation. The spring serves two purposes, one is to minimize movement of the float when the motor gets jiggled around in rough waters and to keep it open when the fuel level in the bowl is low. Too much preloading though can result in fuel leaking into the vent while underloading can result in the float getting stuck in the up or closed position starving the engine of fuel resulting in surging. If the float continues to get stuck in the closed or position, increase the spring preloading to one full turn.
