I'm no carb expert, but it sounds to me like the carburator is dumping
in fuel at low RPM.

You said someting interesting that you had to take off the "breather"
and ..."OPEN THE CHOKE...". To me that is an indicator that the choke
isn't working properly. When the engine is warmed up
the choke butterfly should be wide open and should stay wide open. If
it's closing off at low speed then it's dumping gas into the intake
thwoing your air/fuel mixture way off.



Tconn756 wrote:
The boat is running fine but I have had trouble with it stalling and then
not restarting.
It only happens when cruising slowly. It will sputter for a couple of
seconds then stall.


The only way I have found to get it restarted is to take off the flame
arrester, open the choke and move the throttle lever to full throttle.
I let is sit that way for and hour and it usually starts.

Any idea what could cause this?