Battle Cow

Hey, I was just wondering if anyone could explain to me what a secondary linkage, or primary for that matter is, what they do and how a damaged one might effect the perfomance of my 12a, thanks

trochoid

iTrader: (6)

While your question is a bit vague, I'll see what I can do to help. The stock Nikki 4 barrel carb has 2 primary and 2 secondary barrels. Each has thier own set of linkage, but they are tied together to work in a progressive manner through a vacuum signal. In the following link you will find the FSMs, carb manual and other rotary related reading that you can download and study up on.

Damaged linkage can cause all sorts of driveability/performance related problems. Download the carb manual and compare your linkage to what it's supposed to be. If you're having driveability issues, please describe them in detail along with any damage that's apparent.

http://www.wankel.net/~krwright/cars/rx7/manuals.html

Welcome to the forum. Btw, all newbs are 'required' to post pics of thier newly aquired 7's.

Battle Cow

Thanks trochoid, Ill be sure to check that out. I had just heard that damaged secondaries could slow the car down, and then I got thinking that my seven has been getting pretty sluggish when it comes to picking up any kind of speed. I was pretty much completly oblivious to what people ment when they said secondairies, but it seemed to be a the most probable culprate

flight_of_pain

in my experience, the stock nikki will power the car just fine on the primaries alone, with a top speed of about 105mph. In the stock configuration the secondaries are only opened under heavy load/acceleration. Do you have a bog as you tip in the throttle, any erratic firing under acceleration. If you can describe how it acts in detail, we can help.


isaac

Battle Cow

No bogging or irratic firing, the throtle response just isnt very quick. I've got a conciderably old, stock 12a though, so that might be my problem

flight_of_pain

my first suggestion (and a just plain good idea on a 25+ year old carb) is a rebuild of the carb. if you are mechanically inclined in the least its pretty simple. download the carb manual and tear into it. I have seen the accelerator pumps with torn/bad diaphrams cause slow throttle response, but they typically give a bog on tip in as well.

isaac

blackdeath647

iTrader: (2)

i've got mechanical secondaries and the most i've seen under just primaries is about 85-90mph going on a straight road.

Sgt Fox

iTrader: (3)

Just wondering if you guys use a kit to rebuild the carb as it seems the mazdatrix kit is NLA

74RX4

iTrader: (10)

Check this first
https://www.rx7club.com/1st-generation-specific-1979-1985-18/common-cause-power-loss-nikki-carbureted-models-632007/

Many carb questions including rebuild kits and where to buy them are well covered by Sterling and Carl in the FAQ stickied at the top of the 1st gen main page.

DivinDriver

iTrader: (15)

I just bought a kit through Black Dragon for my 80... very resonable price and it even included the float needles. Was $27 delivered.

Haven't unwrapped it yet (still tearing down my carb) but looking thru the cellophane it looks pretty complete, and the cut gaskets look nice and clean.

DivinDriver

iTrader: (15)

Unwrapped that kit; I'm a little less pleased with it now.

Very few aluminum crush washers; mostly fiber washers for the small round parts. No new crush washers for most of the fuel inlet (only 3? fuel inlet alone uses 6!), only 2 of those tiny cotter pins (carb uses 4 just for linkages, not to mention vacuum parts); o-rings for the bowl glasses insted of cut flat rubbers, no jet gaskets (unless that's what the fiber washers are for?)...

I guess it will still get the job done, and at $22 plus shipping I should be happy I got needles, but I'm feeling some buyer's remorse... now that I've opened it, I can't return it.

Hell of it is, even if I'd spent 3x as much at MazdaTrix, there's no way to tell what's in it til you get it and open it.

Bummer.