12A NIKKI CARB Troubleshooting Tips with The Carb Master - Test Running on the Ground! 

Another reason for the secondaries to not work is having the main body gasket installed wrong. It has to go on a specific way to provid vacuum to the diaphragm; installing that gasket wrong also can affect idle. A good indicator of flooding as well, is that the engine hangs for a couple seconds after letting off the throttle, or if it's flooding really bad the rpm can shoot up a little when you release the throttle. I'm unfortunately very well versed in this, lol. Something else to keep in mind is the shutter valve, if you are keeping it or have not removed/blocked it yet, it can make it idle extremely low as well as run really really bad. This really only happens if the valve/butterfly get stuck closed or the vacuum system is malfunctioning/hooked up incorrectly. Usually this is accompanied by a loud moaning sound, and the hose coming from the valve to the air cleaner will be gulping air. While the carb is off, you should check the valve and butterfly on the intake to ensure they move freely and the valve holds vacuum. Edit: The service manual should tell you how to diagnose the solenoid if you cannot find an issue with the shutter valve itself. The shutter valve helps improve fuel economy and also serves to prevent backfiring on deceleration. If you have a catalytic converter, you should keep the valve to avoid overheating it; especially if it's the factory one. I will say, the float adjustment information is good. You should always check this during assembly! I took my carb apart so many times, and finally checked my floats; they were somehow way way off! Adjusted them and my flooding was fixed immediately! My car has never run this well under my ownership. Something else you can check, especially if you're reviving a car that hasn't run in forever, is the spark plugs. Even after I fixed my flooding, my rpm would dip really low when returning to idle and it would refuse to idle under 1k rpm (as if it had a vacuum leak, but no leaks could be found; it also needed to idle very rich). Turns out I completely ruined that set of plugs with all the flooding I'd had, swapped in a good used set and I was able to idle it down perfectly. Another trick you can use to unstick the floats, is to unplug the fuel pump and start the car. Once the bowls dry up and the engine stalls, the floats will usually unstick in the process. You can also use this to troubleshoot flooding; if it runs better with the pump unplugged, it's flooding likely from the floats. No fuel flow means you can't overfill the bowls from stuck or improperly adjusted floats. Edit 2: I have some videos demonstrating issues I solved that I can upload if it might help anyone diagnose their carb

it would be great to have a video showing adjusting the idle speed, mixture and air adjust screws. My SA is running pretty good but I can't get it dialed in perfectly yet. still idles rough/backfires a little

Really makes you appreciate electric fuel injection

I rebuilt the stock Nikki carb on my first FB a few years ago. This was a great refresher and I'm sure I'll be referencing this video for my future first gen RX7 endeavors. Thank you!

Thank you for posting this video, we have been learning a lot about rotaries since we pick up a 1st Gen RX7 setup for 24 Hrs of Lemons. Dec 4th and 5th will be our 3 race at Sonoma and each time we have learned quite a bit each race and having lots of fun. So must so that i am building a 2nd RX-7 that should be ready for the March race at Sonoma.

Music for my ears ❤

Maaaan, this is what we needed :D just having the same problems now :D

Thanks for this great video! Subscribed with a full bell!

Great video!

Another great video.

i have a 1978 mazda rx7 and we had to rebuild the Nikki carburetor that was in it, and i was wondering if anyone has any suggestions for a no start? I need to adjust the idle screw for the air/fuel mixture but I can't for the life of me remember if you're meant to screw the screws in all the way and then screw them out from that or if it's the opposite way. Any help or suggestions is very much welcome

Hey, I really like your video's, very informative. I just bought my first 81 RX-7 FB which is basically completly stock and complete with only some rust repair and a broken engine. Other than that the interiour is mint and all original. So I will be restoring it to its former original glory. It has bad compression on the second rotor, so I will be rebuilding it and while I'm at it, I will also do some porting. However, I didn't manage to find any info about the drivability with a stock carb after porting. What I would like to know are, what are the limits of the stock carb, can the nikki carb be upgraded? My goal for the car is to be fully stock looking with some extra power under the hood. I will probably install a racing beat full exhaust system as well. I'm aiming for a minimum 150whp with a half bridge. Is this an achievable goal or am I just dreaming? I don't mind some brapping at idle and ofcourse I need some rotary noises when driving. Keep up doing the video's! Thank you!

Amazing tech video, as always!!!

Hello, I have a 83 RX7 12A carburetor and everything on the car is o.e. it starts but once it reaches operation temp the auto chock goes in and the car shuts off unless I press on the gas pedal.

I have a 1985 RX-7 with a 12A engine and a Nikki carb. I must pour a small amount of gas in the carb for car to start and then it runs and idles fine. However, if I turn off the engine and try to restart, I must again pour a small amount of gas in carb to start. What could be wrong? Help!

Hey Love your Carb video. I just got back from a cruise on my 83 12 a rx7 and have developed a nasty coolant leak. Looks like it is right by the carb. and leaking down below the exhaust. i have coolant right on the intake by carb so wondering if these cars have intake o ring or gasket that could fail

Looking good! I suppose you'd be the best person to ask on this, since I can't seem to find much information at all. I'm putting my '79 12A back together, and I'm not totally sure how I'm supposed to time the thing, and I was hoping to figure that out before I try firing it up. From what I'm seeing, it looks like I can unscrew and rotate the distributor a maximum of around 45 degrees. Is that going to be all I need to time it?

I should build a stand to start an engine

Great video. I'm having some strange fuel issues with my 85. It basically won't accelerate unless the secondaries are open. Thoughts?

Charles are you availble to rebuild my 83 Nikki carb?

I’m looking for someone to rebuild my 1981 RX7 carburetor. Don’t know if you’re still in the business or not.

I bought a 1980 a few days ago with a bad fuel pump, I installed a new fuel pump and have tried priming it several times but it won’t get gas to the carb, I tested the old pump and it is fine and seems to pump better than the new one, I’ve blown through all the lines and they seem to be fine and not clogged but still no fuel at the carb, what should I try next?

Whats the FB or IG or RU-vid channel of the carbs pro man?

I threw mine in the garbage and bought a Weber problem fixed

I can't get the secondaries to turn on. Any tips?

79 just intalled a header so had to flip the intake and carb out of the way. . After reinstalling we cannot get it to idle. Any ideas?? runs fine just won't idle.

Hey, I’m having a problem on my 83 12a rx7, maybe you can help me out. After I run the car under load for about an hour, the float bowls start to run low, and the carb starts to starve for fuel. I also have a clear glass inline fuel filter, and the fuel level in the filter gets low as well. I’ve replaced the fuel pump, all of the fuel lines, rebuilt the carb a few times, but all to no avail. I’ve been trouble shooting for 3 months. I need help…Please. I just need a new idea, I feel as though I’ve tried it all. Thanks. -Drew

How about a video on how to pass emissions testing like a pro? 🤔😂

What a horrible thing to do an engine. By running it with no coolant you are causing severe damage to all of the housings. Also where is the oil cooler? Are you running it with no oil pressure? Argh!