I JUST FINISHED REBUILDING THE NIKKI CARB ON MY '81 RX7 GSL WITH MANUAL SHIFT. I HAD TO REBUILD IT AS THE ENGINE WAS FLOODING I ALSO INSTALLED A NEW SHUTTER VALVE. THE CAR STARTS COLD WITH THE CHOKE OUT BUT RUNS ROUGH. WHEN I PUSH THE CHOKE IN IT RUNS A LITTLE BETTER AND WILL HOLD AN IDLE OF ABOUT 800 RPM. IF I PULL THE CHOKE OUT AGAIN WHEN THE ENGINE IS STILL COLD THE ENGINE QUITS. IF I PULL THE CHOKE OUT WHEN THE ENGINE IS TOTALLY WARMED UP THE ENGINE ALSO QUITS. THE ENGINE ONLY RUNS FAIRLY SMOOTH FROM 800 RPM TO ABOUT 2000 RPM. AFTER 2000 IT RUNS VERY ROUGH. I CAN ONLY DRIVE IT AROUND THE NEIGHBORHOOD AS I CAN'T GET IT PAST 30 MPH DUE TO THE ROUGH ENGINE. I USED A J.P. SORENSEN REBUILD KIT.
THE CAR HAD 139,500 MILES. THE FUEL LEVEL IN THE SIGHT GLASSES IN FRONT AND BACK OF THE CARB ARE JUST SLIGHTLY BELOW THE MID POINT ON THE GLASS.

ALL THE CABLES, VACUM HOSES AND OIL LINES APPEAR TO BE CONNECTED PROPERLY.

ANY SUGGESTIONS WOULD BE GREATLY APPRECIATED.

THANKS,

CHUCK

 

we recently just rebuilt mine because the float was stuck and i no if u dont get it just right, it is real sensitive now i dont no if that is it but mine, that is all i have had problems with since i have been working on the car

 

hi wwest2,
thank you for your response to the carb problem with my '81 rx7. per your suggestion i checked the fuel levels in the front and rear site glasses on the carb and they were both
too high (about 3/4 to the top. i removed the air horn and changed the float levels and
re-installed the air horn. i started the car and it still idles at about 800 rpm. i checked the fuel
levels in the floats and they both are right in the middle. if anything the car now runs a little
rougher. if i pull the choke out slightly the engine wants to quit and when i release the choke the engine backfires. i'm sure it's running rich but with the float levels in the middle i don't know why. i did not touch the air/fuel adj. screw when i re-built the carb.
i am officially out of ideas.

chuck

 

i no my dad has worked on this car more than i have, since i am only 19 and the car is thirty years old, i will let him no bout it tomorrow and see if mine has ever done what yours is doing and see what he did, but i will try to get back with you tomorrow if i can.

 

also you might try shooting this guy a message on this forum, i thought bout just buying a carb from him cause he races rx7s and had and still may have carbs if you just want to buy one or he may have advice, his profile name is legokcen he posted on my wall if you just want to find him that way, but i would certainly talk to him.

 

Not worry...check out the numerous write ups in the 1st Gen archive.
Also check out sterlingmetalworks.com ....there is a lot to read, but you'll get some great information on how to tune a Nikki.
Finally, do an advance search on the tool bar ^^^ search terms like "air/fuel mixture" or "tune a nikki" set your parameters for the 1st gen technical section or archive and more than 15 posts.

Good luck

 

dad said he reset the floats just a little short of what the book called for and got a new needle valve and new valve seats

 

Thanks to wwest2 and Patmac. I will go to the threads on tuning the Nikki carb and see if I can get some help there. I used the sterlingmetals web site to get info. on rebuilding the carb
and i'll check it again for tuning the carb. I don't think the carb in the website is from a '81 rx
as it shows the air/fuel mixture screw in the back of the throttle plate. I think mine is inside the soft alloy shield covering it. From other posts i've read it's difficult to get the alloy cover
off without damaging the air/fuel adj. screw. I found some rebuilt Nikki carbs but they started at 350.00 plus shipping. Really can't afford to spend that much.

Again, thanks for your help.

Chuck