So I just bought a 1979 RX-7 and it idles fine, accelerates great, and the motor is tight, but while cruising the engine starts surging or stutters, why is that happening and how do I fix it, I just had the carb rebuilt, and I think that the primaries aren’t getting enough fuel, but when you step on it it goes fast(lol)
from what I understand it could be my fuel delivery. But what can I do to fix this problem?

 

welcome to the board.

things i would check (if you haven't already):
- the mixture
- the floats
- the filter (even though you said it responds to throttle)

 

i just saw your thread over in the Gen 1 forum, so i'm linking that thread here:

https://www.rx7club.com/1st-generati...speed-1161048/

for the future, it would be better to wait 24 hours for a response before cross-posting (posting the same thread in a different forum).