idle problems 2005 115 4 stroke

[Houseboat Jerry]

I have a 2005 Suzuki 115 4 stroke engine on my 50x14 alum. houseboat,
the motor does a great job of pushing and controlling my boat.
The problem is after the motor runs at 1500/2000 rpm pushing the boat
and you slow to idle (600 rpms) the engine dies.
the engine will restart if you open the controls to wide open
The engine will not idle after it has been run at a faster speed.
The engine will set and idle all day with no problem.
This is a real problem when coming into the dock.
need advise.

[artdf175]

Do you have s service manual?
My 150/175 manual talks about the IAC valve
I would check the IAC valve
One of the purposes is to improve drivability when decelerating (dash-pot effect)
Check yo make sure passage way is clean
The valve is located on the intake manifold

[boashna]

start with easy stuff use velero or shell gas and see if problem goes away old gas could be a problem use fuel injector cleaner next don't use fuel injector cleaner unless you have a problem I like stp black bottle for $2.99