Replaced carbs in four stroke outboard - now hear popping

[Lash-L]

Four stroke was leaking gas. I rebuilt all four carburetors. Once I went to synchronize using the carb tune pro synch got worse and engine started stalling. Now carb 2 and 3 will spike on carb tune and I will hear a popping noise every 5-10 seconds and engine will stall. Any suggestions? Replacing manifold intake gasket now.

 

[Faztbullet]

Running in trash can as motor need some backpressure to adjust?

 

[jimmbo]

Are all the Throttle Shafts in Sync, as in All are exactly at the Same Degree of Opening, or fully Closed at the same time?




2 Strokes were some much easier to work on.

 

[Lash-L]

Are all the Throttle Shafts in Sync, as in All are exactly at the Same Degree of Opening, or fully Closed at the same time?




2 Strokes were some much easier to work on.

How can you tell? I think so - but i'm not sure

 

[jimmbo]

On a 2 stroke, it was easy, as the Carbs had to be fully closed at Idle, and the Linkages between them could be set.
Do you have the Factory Service Manual for that Engine? If not, get one

 

[cyclops222]

Tuning multiple carbs after a complete rebuild can create some problems. Lean popping is usually from a LEAN fuel mixture.
Some engines multi carb s are set up to close off some carbs to allow smoother idling. You have to know if the correct carbs are being adjusted.
Some use a staggered opening of the carburetors.
You may have float levels too low.
Multiple carburetors can be very difficult on some engines as they age. & develop VACUUM leaks around the throttle shaft surfaces.
You do need help that is still alive and has diagnosed & adjusted multi carb systems.

By chance did you replace ANY PARTS in the ignition system ?

 

[Lash-L]

Tuning multiple carbs after a complete rebuild can create some problems. Lean popping is usually from a LEAN fuel mixture.
Some engines multi carb s are set up to close off some carbs to allow smoother idling. You have to know if the correct carbs are being adjusted.
Some use a staggered opening of the carburetors.
You may have float levels too low.
Multiple carburetors can be very difficult on some engines as they age. & develop VACUUM leaks around the throttle shaft surfaces.
You do need help that is still alive and has diagnosed & adjusted multi carb systems.

By chance did you replace ANY PARTS in the ignition system ?

My email stopped notifying me of any messages. Sorry I missed this.

I did not replace any parts in the ignition system. After another rebuild and cleaning in ultrasonic cleaner, the boat started and ran without any clicking noises, until I flooded it when I pushed the throttle too much i guess.

On a 2 stroke, it was easy, as the Carbs had to be fully closed at Idle, and the Linkages between them could be set.
Do you have the Factory Service Manual for that Engine? If not, get one

I do have the manual so I followed that for the past for syncing.