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I recently bough an 85 fb and the previous owner had the car in storage for over 20 years. Mostly original, except they replace the carb with a Weber 48IDA.
I found a guy locally who has 2 rx's and raced them once upon a time. He took a look and told me the plugs were wrong. So at his recommendation I replace plugs with NGK 2329 and new wires. The NGKs were hard to tighten, I think I need a thin walled socket. After a short drive, my plugs are black. The car looses power after 2nd. It also, back fires after shutting off the car. Scared the crap out of the neighbors.
Anyhow, now that I've done some post readings, I think I still have the wrong plugs. Should I be using NGK BR8EQ-14?
I also need help tuning the Weber. I have been reading so many posts and youtubes that I'm not sure where to start anymore. Can anyone can point me to the best answer? I live in MA and haven't found anyone to help me. They all hear the word "Rotary" and.............
In the meantime, I'm trying to get ahold of the original carb (the owner says he has it somewhere in his storage). I may look rebuilding it.
br8eq14 plugs will work sure (fyi, NGK 2329 are the same as BUR8EQ14). I personally really liked using bur9eq (NGK5777) for trailing and bur7eq (NGK 6917) for leading. I felt these plugs worked the best for my ported 12a with weber carbs. if your plugs are coming out black you are likely too rich, which could also explain why you cant accelerate. too much fuel will bog the engine out and will limit how high you can rev. Try checking the jetting for your carb and using some of the info in the forum for the correct jetting for your carb and engine setup. good luck.
If the rest of the engine (and exhaust) is mostly stock, then the 48IDA is probably too big. But here's Racing Beat's recommendations on tuning a 48IDA for ported 12A's with their headers - https://www.racingbeat.com/manuals/webercomponents.pdf
I'm not sure about "thin walled". I'd call it a "regular" deep socket. My impact sockets are much thicker, but that's just to stand up to impact guns. I use a 13/16". 21mm also fits, but not quite as well.
The plugs for a 12A are NGK BR8EQ-14, ALSO known as 2329's. I think one is a part#, and the other a stock #, but it's the same thing.
I don't have any issue fitting the socket to the plug. The issue is the socket fitting in the tight space to tighten the plug.
I'll take a px next time I'm under the hood.
clutch failure will have a distinct smell along with power loss. typically when you try to accelerate with a burnt clutch, your rpms will climb but you wont actually go anywhere.
If your clutch grabs in 1st and 2nd, it shouldn't have any teouble grabbing in 3rd and 4th. I think it's your over-sized carb. And the fact that the engine hasn't run in 20 years and everything needs a thorough go-through.
"Barn-find" cars are only good for body work. All the tubes, gaskets and bushings rot over the years.
you never answered Maxwdge's question about the car. is it otherwise stock? trying to tune a Weber on an engine without an exhaust system will make a relatively complex process even more complex.
as for the spark plug issue, if you're being forced to used a thin-walled socket, then you don't have stock plugs in it.
in my experience, with a performance carburetor, you may or may not want/need to run the stock plugs, but that's a discussion for a future time. solve your current problem first.
and just for clarity, your exhaust includes a header?
use the stock plugs until such a time that you have the car running well enough to start experimenting.
for right now, i think what you need to do (and this is just an opinion) is:
1. figure out how you are going to remove the plugs without spending the ridiculous money RB is charging for their socket now
2. get a notebook, you will need a journal
3. document what pump you have, and how your Weber is currently set up (jets, emulsion tube, etc.), and fuel pressure
4. see where your timing is, and document that as well
5. read this: https://www.rx7club.com/1st-gen-gene...paper-1145099/
Thx. I got some work to do. I will let you know how it works out!
Also, car was in a temp controlled auto shop. Wasn't driven but started periodically.
Btw, I have been reading a lot and i have a great appreciation for those of you that figure it out. I'm learning by the seat of my pants. My grandfather, who was a body man for 50 years (mechanic by default some days), is directing me. He's trying anyway.
Last edited by Jax85fb; 04-29-22 at 12:34 PM.
Reason: adding
These cars are very simple, mechanically, but are old now. So it's pretty much the norm that the fuel has gone bad, the vac lines have dried up and cracked, the gaskets are leaking, etc.. Most problems you'll run into are "common" around here, and everybody wants to help a new guy out. Welcome to the club!
I meant what I said though, about the 48IDA being too big for a stock-ish 12A. Racing Beat says a 48 is too big for a stock 13B, so... unless you plan on running the engine at redline all the time, you'd prolly be better off with a diffetent carb. A healthy nikki is def the best carb for a stock-ish 12A so I'd suggest getting the original carb from the previous owner and rebuilding it. A second choice would be a RacingBeat 465cfm Holley, although my 12A ran better with a heavily modified 390cfm.
Point being, I have a 48IDA for my street-ported 13B and Im hoping it isn't too big for street use. Hopefully I'll find out soon (hoping to drop it in the car in the next couple weeks).
04-26-22, 03:34 PM
No Power in 3rd or 4th gear
