Re: 1990 VRO Evinrude 70 HP
Cold start, warm start, or both? What's your cold start procedure?
What spark plugs you running? Are they in good condition & gapped at .030?
Worn float valves, or misadjusted floats, can give you a slightly flooded condition when you come off a hi-speed run, making it reluctant to idle or start. Carb rebuild will fix that.
Idle speed set too low is another possiblity, but if these symptoms just started, you'd want to fix the problem instead of masking the symptoms by adjusting the idle.