84 merc dies at full throtle

[rwb]

Hi i have a 1984 90 hp merc in

Hi i have a 1984 90 hp merc in line 6cyl
starts hard sometimes after it starts it runs fine but when I throtle up it planes out and then boggs down cleaned carbs new fuel lines rebuilt fuel pump new plugs can't find the problem what do you sugest.

 

[fastjeff]

Your carbs may be opening too

Your carbs may be opening too soon. The spark advance has to be mostly in before the carbs start opening.

Jeff