1974 Valiant Scamp, timing retarding when revved

I just rebuilt the carb with the stock 98 and 95 jets last night, the tuning kit should be here tonight with the new springs. I will give the carb a try, set the timing, and fueling. I'll also take the fan off and try it, the shaking really is what bothers me. I hope it's the carb, but it wouldn't be the first time I had a harmonic balancer go bad either.