no power bfore 4000 rpm
 

just bought my first example of the FC RX-7. It is a well-worn 1986 NA. Came very cheap, I just couldn't pass it up. The car is hard to start, i have to hold it to the floor and it fires up slowly, with a bunch of smoke and smells like a lawnmower or something. I find it great fun, its a blast.

the car runs funny, it has no power before about 4000 rpm or so, but after it revshigher than that it runs great. the power comes on instantly, like flipping a switch. the guy who sold it said he thought the timing was off, after examining the CAS, it looks like someone has cut out the adjustment slot of the CAS to allow more clockwise rotation of the aforementioned component.

Why would someone do this?

I look forward to upgrading this car and learning about the rotary engine.

I don't know if this will help you out or not, but there are lots of threads about the same hesitation you are experiencing

Search the keywords "3800 RPM hesitation" or something similar, I'm sure you can find a lot of info about the problem