How do I slow the idling speed of a 1984 E4BRHCRM

[Ed Jenkins]

My motor will not run slower than about 1500rpm. The lean/rich control for idling doesn't due anything to help idle. It has to be approximately in the middle to run at any speed. It runs fairly well at higher rpms but I need to slow it to put it in gear.

What do you advise ?

[boats.net]

Start with the slow speed adjustment screws. One at a time.