Hello, I have a Force 1991 50 HP model #507X91A that was purchased 5 years ago that ran at that time and has been sitting since. I tried to start it recently and it did not run. I read alot in the forums and did the following. I checked the spark to both cyclinders is OK and the compression check on each cylinder is 130. I rebuilt the two stage fuel pump with new diaphram, gaskets, all valves, and fuel screen. I took the carb off and cleaned it. It did not look bad inside. The needle, float, fuel jets, idle mixture screw all appeared to look ok. Replaced the fuel bowl and flange gaskets. Reset the idle mixture screw to 1 1/16 turns. The choke operates correctly. Used fresh gas at 50:1 and installed an inline fuel filter. The only way that it will start and run for any length of time is if the throttle is disengaged and pushed full forward then it will start and run at high RPM. If the throttle is pulled back towards neutral it stops running. Cannot get it to start and run in neutral. I have it in a tank (large trash can) of water for testing. I put a "pee" hose on it and the impellar is pushing a strong stream of water. I noticed a grey sludge film covering the entire surface of the water after running and testing. I drained the lower unit to inspect the gear oil. It was a blackish green in color. Might this have something to do with the problem? Is there something else that I should trouble shoot or be looking at? Any ideas would be greatly appreciated!
