Hi all, this is first post, as of two months ago I did not have any rx-7s now I have an 85 gs and a 85 gsl-se. I not too familiar with carbs or rx-7s for that matter. I wrenched my 12a back from near death and not there are a few things i would like to fix up before sell it. The gsl-se im currently having the 3rd member repaired, once that is done im planning on selling the 12a and dd the 13b. So my issue with the 12a is that after I load up the engine (full throttle) I sometimes feel a surge of power at 4K ish rpms. It feels a little like vtec. When i let off the gas, the rpms will shoot up, sometimes to the red line for a second or two and then come back down. The longer I am at WOT the longer the RPMs will surge for before they come back down. It seems like the problem is more of an issue after the choke is finished and before i really start pushing the car. My engine temp usually sits around 1/4 to 1/3 from cold. The more i beat on the car the better it seems and the smoother it drives. Once it cools down it goes though this process again. Anyone have an idea what this this could be, maybe my carb is out of whack. Besides the surging, there doesn't seem to be any other mechanical issues with the car. Idels well below 1K rpms, sometimes skips a beat but in general idles smooth. Vac hoses look good and rats nest is intact.

 

It seems to me that generally everything with that carb seems fine but take some time to deccel after WOT . It might be that the secondary linkage from diaphragm to throttle could be a little sticky ; it may be that way from lack of use (mellow previous owner) and could clear up with more use . Just a thought ....