Mercury 50hp 3 cylinder - Fuel, Spark, 120psi compression - No Start

[bigshrimpin]

Hey guys - I know this isn't a race motor, but I'm hoping that someone can point me in the right direction . . . I have a clymer manual and it's no help. Service manual is in the mail.

I recently bought a 1989 Mercury 50hp that's in beautiful shape. The trigger and stator were bad . . . after I replaced them the motor has spark in all 3 cylinders (when I ground the plugs to the block).

Tested compression = 120psi in all 3 cylinders

replaced fuel pump, filter, cleaned carbs . . . fuel system is supplying fuel to all 3 cylinders.
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When I put the plugs (New plugs = NGK BU8H) back into the motor . . . I swear there's no spark.

The motor doesn't fire at all. Doesn't kick over . . . no smoke . . . nothing.
even with a fully charged battery and fresh fuel. I even dipped the plugs in fuel and put them back in the motor.

What am I missing . . . besides a brain?

[Bruster]

My first guess is the wiring connected correctly? Mark the flywheel TDC for each cylinder. Connect an inductive timing light and see if all three are firing where they are supposed to.

[bigshrimpin]

Thanks!! I don't have a timing light or gauge, but I got it started this morning. I replaced battery harness, charged the battery, pulled 2 plugs and added a little fuel on the one. Fired right up on the one cylinder. Repeated with 2 and 3 and the motor fired up on each one. Then I put all the plugs back in and the motor started right up . . . something is still screwed up cause the motor just starts racing no matter what the throttle position is ??? Anyway . . . I'm excited I got this far.

[Bruster]

Thanks!! I don't have a timing light or gauge, but I got it started this morning. I replaced battery harness, charged the battery, pulled 2 plugs and added a little fuel on the one. Fired right up on the one cylinder. Repeated with 2 and 3 and the motor fired up on each one. Then I put all the plugs back in and the motor started right up . . . something is still screwed up cause the motor just starts racing no matter what the throttle position is ??? Anyway . . . I'm excited I got this far.

I'm still thinkin' you have a timing problem. Did you use the right stator? Is it clocked in the correct position? Timing test will answer these Q's.

[bigshrimpin]

Thanks Bruster!! I'm ordering a timing light and Dial Indicator today. Idle adjustment seems to have done the trick . . . but springs on the carbs won't close the butterflies all the way . . . Pushed them shut with a screwdriver and adjusted the idle screw. Now it's idling perfectly 700/800 rpm and starts immediately (1 - 2 seconds after I turn the key). It's pumping water very nicely too.