2008 Mercury 9.9hp 4-stroke starving for fuel

[speed_demon]

2008 Mercury 9.9hp 4-stroke

It ran great when stored last winter but when I tried to fire it up today it fires up easy with primer but quickly dies. If I keep pumping the primer (engine primer, not fuel line) it keeps running. With some throttle I was able to keep it running without primer and after warming up it would idle without choke but it wouldn't rev up. I drained the fuel bowl (fuel was a little yellow) and pumped fresh fuel through the lines but still doing the same thing. I finally pulled the carb and thoroughly cleaned it. Still the same thing. Other than pulling the carb again and letting it soak I'm stumped.

Any help is greatly appreciated.

 

[Star]

This carb is easy to take apart, but not easy to clean. The idle circuit plugs up if you leave fuel in it. you have to clear the line that appears on the back side of the throttle butterfly. The problem is that there is a restrictor in that passage. The best way is to soak it for three hours in a chemical soak Berrymans from Walmart. Follow the instructions it is not nice stuff. Once you get it cleaned it is not a bad carb. There are other issues that will hurt you. Mercury used a liner in their silver fuel line from the tank that falls apart and breaks into little pieces. This can accumulate in the filter and will shut off an engine running at full throttle. If you restart the particles drop down and allow fuel to flow again. Try to remember to open you tank vent because the fuel pump WILL try to turn your tank inside out.

 

[Star]

Well speed_demon you are not going to get there with a 9.9! This carb/ fuel system is VERY picky. Many posts on this very problem. The idle circuit gets plugged up when you leave our wonderful ethanol gas in it over time. The passage you have to clean is difficult because it has a tiny restrictor in it. The most successful way to clean it is to use a good carb soak for two or three hours with some agitation

 

[speed_demon]

I guess that's the next step. I'll pull the carb and soak in some chem-dip.

 

[speed_demon]

I guess that's the next step. I'll pull the carb and soak in some chem-dip.

 

[speed_demon]

Can anyone tell me if this carb has throttle shaft seals or an o-ring on the needle seat? Or maybe someone has a link to a service manual?

 

[speed_demon]

Running like a champ! Soaked in chem-dip for 3 hours and blasted the crap out of all passages with carb cleaner then air. On this particular carb do you suggest stabil this fall or running it dry or both?

 

[MH Hawker]

both , running it dry at the end of the day is the best policy and a fuel cleaner works real well.