Mercury 9.9 4 stoke Stalling

[festx1]

I fired up my outboard for the first time this year and it idled rough and stalled when given some throttle. I took the carb apart and did a thorough cleaning. The idle is now smooth but it still stalls/hesitates when given some throttle. There's a little plunger on the carb attached to the throttle that injects a stream a fuel when given some throttle to prevent stalling. The plunger is also attached to the small primer bulb. When I depress the plunger by manually by hand (the same way the throttle linkage does) the engine doesn't rev up. However, when depress the plunger it does. I believe this is the reason why it stalls when given some gas. Am I on the right track? Thanks in advance!

 

[festx1]

Here's a pic for reference. The arrow is pointing to the plunger I mentioned in my previous post. My question is: When I depress the plunger, is the motor supposed to rev up? If so, I think I have found the issue, because nothing happens when I move the plunger. Thanks.

 

[Star]

open the choke and look in the ventury, when you push the accel pump you should see gas squirt out inside the ventury. There is a diaphragm, tiny O-rings on that plunger and a check valve in the bottom of the carb bowl. Mercury doesn't have a part number for the O-rings, I got mine from Tohatsu!!!!