I've recently acquired a 1980 RX-7. It's a bit rough but it was mostly intact. It was a non-runner when I got it, but I've happily managed to get it running and driving...but it runs poorly. It doesn't idle well and is low on power at low rpm's (picks up a bit at higher rpm). I tried adjusting the idle based on guides that I found on this forum, before I checked timing. But I could not get it to idle below 1200rpm. I've done a rat's nest delete and replaced any remaining vacuum hoses. I was checking around the carb for vacuum leaks by spraying brake clean everywhere around the carb. The only leak that I found was on the secondary throttle shaft on the front side. So, I decided to pull the carb and see what could be done.

Which brings me to my issues.

First, I pulled the secondary shaft out and it seems there's not much I can do about the leak there. Either the shaft itself or the bore is obviously out of spec. No seal or anything. Unless someone has a solution?

Second, the butterflies on the secondary look like someone went at them with a file or who knows what (pics attached). How much could the resulting leaks past the secondary butterflies be affecting idle?

Related to 1 and 2, does anyone have a source to buy the secondaries shaft and butterflies? I bought a rebuild kit but it obviously does not come with parts like that.

Lastly, when I removed the throttle body I found a small pin laying on my work table (pics attached). I have NO idea where it came from. I've looked through all schematics and the Hayne's manual and cannot see or find any reference to this pin. Anyone able to tell me where it may have come from?

Thanks in advance for any help here.

 

Dang... with someone having been in there before, it's hard to tell without REALLY going through it thoroughly what's right or wrong.

You might be better off trying to source a used but known good condition nikki and slapping it on instead. There could be untold problems with the carb you have that someone before you tried to "remedy"

 

It was definitely monkeyed with. It was half torn apart when I got it. ALl of the linkages were off. But you're right, there could be internal components missing and I wouldn't know it. I was trying to be ultra careful and I still ended up with an errant pin. The way the butterflies are hacked up, I'm guessing whomever was in there before me probably wasn't taking much care.

Should I be looking for a Nikki...or is there an easier/better/cheaper alternative?

 

OK, got the pin sorted. Turns out there are two pins (found another one on the floor...clearly I wasn't being very careful). I was blowing air through all of the passages on the throttle body and realized two of them didn't go any where. They hold these positioning pins. One problem solved at least.




I'd still love to hear if anyone knows where I can get the secondary butterflies and shaft? Or perhaps just the whole throttle body?

 

I suspect that someone was trying to get the secondaries to close correctly by filing them down. Wrong solution. You have to put them in loose at the screws and very carefully exercise them through the full range, slowly tightening as you go until it they move freely and close completely when closed. You should get another throttle body or a whole intake and nikki setup thats unmolested. No telling what kind of hacks were done incorrectly to that poor nikki.