Stock 83 GS losing power during higher acceleration.
 

I searched through the FAQ and did some googling, but found no answer to my problem. I picked up an 83 GS last week and finally got it home today. It drove great over the 300 mile trip I had home, except I was having trouble going uphill, would start surging and acting like it wasn’t getting enough fuel. Topped off and the next hill I hit, same issue. Okay no big deal. Replaced the fuel filter and that issue is gone now. But I noticed while cruising through town if I try to speed up my car basically stalls or cuts power and as soon as I downshift it comes right back. It doesn’t die or anything, I just lose my momentum and rpms tank. I’m terrible with describing things but I hope that’s enough for you guys to maybe help identify what my issue could be... here’s what I have tried so far:

-cleaned spark plugs, weren’t to bad but I have a set coming in tomorrow to put in.
-fuel filter
-tuned carb using guide I found on here (I assumed that just maybe it wasn’t getting a good fuel to air mix and higher rpms were causing the problem to occur)
-checked a vacuum lines off of intake

everything on this car is stock. If that helps.

Welcome to the board. :)

My first thought is to ask if the secondaries are opening. In the event you have no idea what I'm asking - are you getting a surge in power at around 3500 to 4000 under acceleration? If not, then they are probably disconnected.