86 150 stalls at idle

[rickclark]

First time out after rebuilding carbs and tuning to specs. Started fine, accelerates great and runs smooth when on plane.
But at idle, the engine "coughs and sputters" then dies Have idle turned up as fast as possible and still shift
(approx. 1200 RPM), but it still "hiccups" and stalls. Could it be fuel pump? All input welcome.

 

[robert graham]

are the idle screws/jets set about correct number turns out from lightly seated...usually about 1-1/8 to 1-1/2 turns out, give or take. Of course the idle jets and circuits are clean?...1200 RPM idle is a bit high(not good for lower unit shifting)....should be in the 750 to 850 RPM range....

 

[rickclark]

Thanks for your input Robert. Set screws at factory specs. Should I try adjesuting their setting a bit, or best left to specs? (I'll double check I've set them at the correct number of turns out from lighty seated) Had idle seet high to try to keep running. Usuall idle around 850. Thanks agiain for your input.

 

[99yam40]

if all the passages are good and clean then setting to specs should work properly
May need to clean again. Sometimes a heated ultrasonic cleaner is needed

Sounds like a lean sneeze, so pilot passages need more cleaning