What type of gas do I use for the FB? Also why is there a loud whistling noise in the carburetor? Another thing is that when the car is under idle, there is a strong smell of fuel. My FD doesn't smell like this.

 

for FB's use regular...strong smell of fuel might be that its running too rich...search and you'll see.

 

n/a rotaries like 87 octane. i did a poll on this a while back. search, it has some usefull info on it.

 

I don't like the smell. Can I use premium?

 

you technically can use whatever you want... maybe your cats arent working correctly? it might not be the gas your using... i would check out your emission system (if its still there, if it isnt, then thats probably what smells)

 

higher octane is usless on a na..

at least thats what ive been told

 

what does the manufacturer reccommend? Also why is there a loud whistling noise in the carburetor?

 

reccomended gas is 87 octane from the pump in an na rotary.....

-greg

explain where the noise is coming from

-greg

 

When I put my hand on the intake, it quiets down just a bit. When I take the cover off, it becomes louder.

 

Do you still have the Flapper valve in?, if so take it out, its a worthless pos..
that could be what the noise is
-greg

 

How does it idle? If it idles like crap then the noise could be from a failing shutter valve. Good luck!

 

87 is what you should use. You can use higher octane...it will burn slower obviously and give you less power but slightly better gas mileage.

This likely has nothing to do with your problem though.

F-

 

Octane = resistance to detonation

Put simply high octane takes more pressure to go boom. Turbo'ed engines require higher octane gas to prevent pre-detonation which can harm the engine.

Relatively low compression engines like our N/A rotaries thrive far better on 87 octane - a higher octane just means more work for the engine to do to get the same explosion.

 

I personally run 89 octane. I prefer this because of the better cleaning properties of higher octane fuel... Also seems to run a bit smoother near redline.

 

My car has trouble starting on anything other than 92- it idles much better with 92, as well... My 12a was the opposite...

 

Weird... I've only run 87 because that's what the manual says. I've never tried a higher octane.... I wonder how my own car would perform. Either way, if your car is stock run what Mazda tells you to run, they ought to know!

 

listen to mantis.

The noise in your carb is just the sound of air being sucked into your engine. Next time you open a can of soup or veggies or something take both the bottom and the top off and blow in it at an angle. If you can give it a good enough blow job it'll make a whistling sound. I've never tried this, and if you do, don't admit it, we;ll laugh at you.


It's prolly just a typical carb noise.

 

Thank you for all of your input. I would like to clarify on the noise, its a loud whistling/squeeking noise almost like a muffled pig squeal and its coming from the whole intake and carburettor. It's an annoyance.

 

You should probably do like ppl here have suggested and check the flappers and butterflies and stuff. If it's loud enough to actually bother a person I can't see it being just intake noise. Something would probably be stuck and limiting the airflow...resistance=noise.

 

Okay, I will check on that shortly. I have a few questions unrelated to the topic. What is the sub-zero reservoir used for? The pump was dead and I had just replaced it. What is its purpose? Also, my car is hard to start, how much do you have to pull the choke to start it(halfway, quarter way)? My tachometer is still dead after changing the plugs (someone advised to do so and said it would fix it). BTW it was dead when I bought the car.

 

check tach cable in tranny

 

that's speedo buddy...lol

The tach feeds directly from the trailing coil. There will be a lead on the coil...make sure it's clean and connected.

Sub-zero resavoir...I don't know what's supposed to go in there but the whole idea is to help your car start when in extreme climates (read: very cold). I think...I'm not certain.

Every choked car I've ever driven I've always pulled the choke all the way out if it wouldn't start immediately. I'd give it a couple cranks. Then I'd put it just under half, hold the throttle, and give it a lil cranking and it'd fire right up....even if it was really cold. RX7's are not FB's, however, but I think it should work the same.