1969 Mercury 500 50hp thunderbolt ignition running poorly and stalling

[classicboater1969]

I am having an issue with my 1969 Mercury 500 50hp running poorly and stalling. The fast idle does not rev very fast. When I had in out in the water it would idle rough and soon as I put it into gear at low speed it would die. Once I get it running and at full throttle on the controls it is not have any power and sounds like she is missing as she is sputtering. If I advance the ignition driver more forward then it is in forward gear at wot it starts to sound much better. I rebuilt carbs and fuel pump last year. I think the timing is out of sink with the carbs. Please help!!!!.

 

[GA_Boater]

Finally :welcome: aboard.

First thing to do is check compression and verify spark on all 4 cylinders.

Did the motor run better after the carbs and fuel pump were rebuilt?

 

[classicboater1969]

I do have spark and compression on all 4 cylinders. I rebuilt the carbs and fuel pump as I was having a problem with a dead spot on the throttle that when I went from slow idle in forward gear to wot it would bog and die. This condition i just mentioned was on going since I rebuilt the motor back in early 1990 as #1 cylinder piston rings failed and had to do a complete rebuild. To answer your question that the motor ran not so good after the carb and fuel pump rebuild as I think i did not set the carbs correctly and might have messed up the timing since I had to remove the ignition stator to get at the carbs properly. So I don't know if I have the idle set correctly along with the advance timing.