Mercruiser 120/2.5L timing problems

[Pierre Ledoux]

Hi, I have a 1984 Imperial boat with a 120/2.5L Mercruiser. The boat is not new but seems to have been well taken care of. One thing that does not seem right is the engine. It will only idle properly around 950Rpm, which seems a bit high. When RPM is lowered via adjusting screw, it sputters and dies. The choke seems to be properly adjusted as it on when cold and opens up when the engine is warm. I tried to time it but I donÂ’t know if I am doing something wrong but the timing mark is way off the timing tab, itÂ’s like almost 2 inches to the left of the timing tab. I am hocking up the timming lights to the first cylinder, the one closest to the damper and accessories. If I try to bring it closer, the engine will die before it hits 12 btdc. The engine pulls strong up to 4200 RPM when on the water but does seem to run rich from the black deposits in the exhaust and costs a bit more in gas then it should. There is only a slight hesitation if I dump the throttle for standing still but I guess this is a bit normal.What could be wrong? Does this engine use timing gears or a chain? Could it have slipped a tooth or two? The points seem ok as they where replaced before I acquired the boat, could it be not installed properly? ItÂ’s been years the last time I worked with points and I donÂ’t remember the procedures for adjusting them. Any help would be greatly appreciated as I wants to enjoys whatever left of the summer Thanks.

[Mod3]

Moving to I/O troubles and repair.