1986 Force 15 hp Cough

[JDusza]

Hi,
I have a 1986 Force 15 hp that has been a great motor for me.
There's only one adjustable jet on the carburetor.
The engine runs excellent at high speed but when it idles it coughs.
It seems to me that when I adjust the jet to rid the cough, I trade off high end performance.
Any ideas?
J

 

[jerryjerry05]

That screw isn't a jet, it's an air/fuel mix ratio screw.
It should only affect the idle operation of the carb.

If the carb looses performance at high speed then the float may be set wrong?
The reeds cracked or broken?
Check the fuel pump too.