falkenfighter

I just bought a 84' Rx7 Gs. It has 147,000 miles and runs alright. The previous owner had the carb rebuilt but for some reason its still running really rich and idles slow. I tuned the mixture screw but it still runs really rich and still idles at about 500 rpm. I have to clean it out whenever i come to a stop cause it wants to load up on me. Ive done some research and found that the holly 465 carb is about the best bang for your buck. Should i get the holly and solve all the carb problems or try and salvage the old nikki? Also another question about carbs. My friend just bought an 85 gs at the same time i did. He wants to put and edlebrock 750 on it. I told him that its way to much carb but he just doesnt believe me. I think he will start to blow anything thats weak on that motor. Am i right?



The car has kinda high miles. Is there anything i should worry about in terms of the motor lasting or having any problems in the near future. My gas gauge went out so i ran out of gas the other day. Is it gonna be costly to repair or replace the gauge? Also what kinda gas milage should i be getting? I only got about 145 miles on a tank. I think there has to be something wrong cause i think it should get better mileage than that.



If anybody has any suggestions on what i should do first to build this car up and make it faster im open to any good advice and if anybody knows where to get some aftermarket wheels for these cars let me know cause i cant find any.



Thanks

j9fd3s

in my experience "carburator problems" usually turn out to be something else (vacuum leaks, bad ignition etc). although since yours has been played with, there might be a problem



145 miles to a tank is low though, should be in the 220-260 range (about 18-22 mpg)



fuel guage probably needs a new sending unit, although if the car has been sitting ive had really good luck with those fuel system cleaners, and just driving it

diabolical1

what fuel pressure and pump are you running?

falkenfighter

The car is all stock except for an exahust that the previous owner made for the car. Its just straight pipe through one muffler. And does anybody know if there is any good rotary mechanics in the Kansas City area

djjjr42

You can find another stock Nikki carb rather cheaply and easily. You should definitely be getting better mileage than that. You could also have fouled plugs, clogged fuel filter, or bad timing. If you don't know about the prior maintenance done on the car then you should first give it a good tune up. New filters, plugs, wires, dist. cap, and rotor. Change the oil and replace any rubber hoses and belts that show signs of fatigue. If you don't have to worry about emissions (and it sounds like you don't with the straight pipe exhaust) then I would recommend the rats nest / emissions removal with your current carb. That's getting rid of most of the vacuum hoses and all but the AC solenoid, the air pump, and will help your hp. More importantly in your current situation, you will then be able to determine if you have a true carb problem, as only minimum vacuum sources are used. This mod is also very cheap and is commonly one of the first done on an RX-7. I recommend that you use the site search feature to find out more about your car, check out the FAQs, etc.

djjjr42

As far as the 750 goes for your buddy's car, I would think that's way too much carb for a stock 12A motor. He wouldn't necessarily blow anything up, just burn a lot of gas and have his motor not even approach the fuel needs that a carb that size can deliver. If you go to an aftermarket, take a look at the Weber carbs while shopping around. I personally use a Weber sidedraft DCOE 45 and I love it. Very streetable and good power increase. The longer runners help with low end torque that the rotary is lacking in. With a healthy motor, this carb (with proper tuning) and good exhaust you can expect 150 hp at the flywheel, a 50% increase over stock. The Mikuni and Dellorto carbs are similar but are much harder to find parts for.



AS far as the wheels, if you have the 4x110 bolt pattern there aren't a whole lot of options. Check out the Konig rewinds on mine these are 15x7 with 4x110, 20mm offset.

falkenfighter

Thanks alot everybody. I have replaced the plugs,oil (and oil filter), and the air filter. Ive heard alot about webers but i personally dont like them and probably wont use them. I know you can get good power from them but the ones that were on my uncles MG and my friend has them on a older honda motorcycle. In my experiance the webers are kinda tempermental and are costly to fix if anything needs to get replaced. I was thinkin of a Holley 465 with a racing beat intake from Mazdatrix. Is that a good plan?

djjjr42

That'll work. You may be able to find a good used setup here or on rx7club.com. The only negatives I have heard on the Holleys is that some say they don't match up well with the rotary engine. Many more have said that they slosh fuel around badly in the turns, even with center hung floats. In defense of my Weber, I can get parts for it rather easily and cheaply. Jets are like $1 apiece, a rebuild kit about $15. Best of all, with a flathead screwdriver alone I can change my idle, mixture, and all the jets in less than 2 mins!



FYI for aftermarket carb install you will be removing the air pump and the "rats nest" so you might as well get it out of the way now. It makes troubleshooting problems much easier once all the emissions are removed. I would def. recommend a new fuel filter (I didn't see you mentioning that you replaced it) because these cars are old and sometimes the gas tanks are bad about rusting and in turn clogging the filter quickly. I have heard of many supposed problems fixed by that alone. Amazing what $3 can do sometimes!

djjjr42

Here's a cheap holley carb and intake, with something attached. I think its road trip time to Chicago for you!

falkenfighter

I checked the fuel filter and its brand new. My friend put a pair of kawasaki ninja carbs on his CRX and has had great success. Does anybody think that they will work on the 12A?