Accelerator pump issue

[bighermHK45]

The accelerator pump on my 1999 Mecury 115 HP 2+2 is pushing gas out the hole (pressure release) while motor is at idle. It is not a dribble, but a pretty good stream pushing 2 -3 inches away from the pump housing. What would cause this? And how do I fix it?

Any advice or practical experience would be appreciated.

 

[Faztbullet]

Cracked/split diaphragm.....

 

[bighermHK45]

Cracked/split diaphragm.....

Took apart the accelerator pump. The diaphragm was cracked in 3 places. Enough that you could see the mesh screen it covers. Got one on order. Is it a safe bet to say once the the pump is rebuilt it will smooth out the idle issue I am having? Or does it not affect that circuit of the fuel system?

 

[Shawnmm]

The accerator pump, boosts the fuel in that line to the pop off valves which open at like 12 to 14 psi I think. If the bowls in the carbs where basically full of fuel when your idling then the accelerator would not be the problem. Usually when that motor is not idling well, a carb cleaning smoothes it out. I usually don't use a carb kit unless I actually find a bad part. Canned carb cleaner and compressed air works wonders. You cant just spray down the throught of the carb. They need to be dissasembled. The bottom carbs do not use an idle cuircut, so keep that in mind.