Problem with transition from idle to full throttle.

muchco

Petty Officer 2nd Class
Joined
May 10, 2005
Messages
143
1986 Evinrude 120 hp V4 Looper Model#E120TLCDC

Hi, my brother and I just installed 4 carb kits in his 1986 120 looper. The motor now starts and idles great but it stumbles on the transition from idle to intermidiate or full throttle. You have to push in the key and prime it to get it to make the transition from idle to full throttle. Once it gets going it runs fine until it slow down and then it stumbles again. Because we have to prime it to clear up the stumble this tells me it's most likely a fuel related problem. The carbs were cleaned and new kits were installed. The weird thing is that we have fixed one problem and created a new one. Before the carb kits it did not stumble on the transition from idle to full throttle, but it started and idled terrible. We now have the starting and idleing problem curred but we have created a new gremlin. We have checked the link and sync several times and it seems to be correct. Could this possibly be a float level issue? Would the throttle pick up timing effect this. We have a 1989 service manual and the link and sync procedure seems the same until we get to the throttle pick up timing. Was there a change from 1986 to 1989 in this area?
Any and all response would be greatley appreciated.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Problem with transition from idle to full throttle.

Throttle pick-up most definatly will affect mid-range and acceleration. So will float level. So will a sticky timer base.
 

muchco

Petty Officer 2nd Class
Joined
May 10, 2005
Messages
143
Re: Problem with transition from idle to full throttle.

Thanks for the response. I will see if I can locate a 1986 service manual from my dealer and check the float levels, pickup timing and timer base.
 
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