Mercury 2 Stroke 9.9 "Popping" during idle

[scubadog]

Hello.
I have a Mercury 2 stroke 9.9 outboard engine that will "pop" occasionally during idle. This "pop" seems to send the engine idle down to almost a die and then the idle will slowly come back up to normal RPM. It almost sounds like it effects the gear as well but I am not sure. Each time it occurs, the smoke increases. Any thoughts would be appreciated.

 

[crem1]

Re: Mercury 2 Stroke 9.9 "Popping" during idle

Either your oil to gas ratio is off or your carburator needs adjusting

 

[Lone Duck]

Re: Mercury 2 Stroke 9.9 "Popping" during idle

Either your oil to gas ratio is off or your carburator needs adjusting

Or you have water in the fuel.

 

[CharlieB]

Re: Mercury 2 Stroke 9.9 "Popping" during idle

If the occasional 'pop' symptom is combined with the motor also becoming just a little bit slower on acceleration then it is a sure sign that it is time to clean the carb. Mineral/crud accumulation has restricted the fuel flow in the idle circuit, leaning the mixture, causing the motor to show the classic 'Lean Cough'.

If the idle is slightly lean then it also stands to reason that the main may be restricted also, adjusting the idle jet can cure the Lean Cough and restore acceleration, however, continued operation with a restricted main jet can lead to serious damage to the motor.

It would wise to take care of the carb now, thus sparing any possibility of more expensive repairs later.

 

[scubadog]

Re: Mercury 2 Stroke 9.9 "Popping" during idle

Wow. Thank you so much. Can the Carb be cleaned using a solution without having to remove it? I am not skilled enough to take on removing the carb and putting it back in. Any recommendations on off the shelf product options?

Thank you very much.

 

[crem1]

Re: Mercury 2 Stroke 9.9 "Popping" during idle

To do a proper job you have to take it off and take the bowl off and submerge it in a solvent for half a day, then buy a replacement kit