20Hp Mercury High Idle And Sputtering @ WOT

[Baitcaster]

Ok Fellas I am trying to figure out what is the problem is with my 92 Merc 20hp manual start.

It starts right up within 2 pulls, it seems to be idling higher then it should, and I cant find any adjustments but the low speed idle screw and I did adjust the screw back and forth to 1 1/4 to 1 1/2

When I put it gear it seems fine until i get to the mid range RPM's and higher. It starts to sputter and pop pretty good with some smoke. I have cleaned the entire fuel system a couple of times, New Plugs, filter, And I have good spark and its running on both cylinders at idle that i know of? Any suggestions?

 

[Baitcaster]

Re: 20Hp Mercury High Idle And Sputtering @ WOT

I fixed it! It was the switchbox the whole time. I swapped it out with my buddies blown up Mercury 25hp and what do you know back to normal running condition.