Hi Folks,
I'm new and need help with my '85 GSL. I bought it and it was sitting in a garage for many years. When I bought it the original carb was in a box on the floor. I rebuilt the carb and tried to put all the vacuum tubes and sensors as much as I could but I could use some help with a full diagram if possible. There are 2 clear oil lines that are very small diameter that come up from the front of the engine and end near the carb. I am not sure where they go and I looped them back on each other. I can get it to run and idle but if I take it around the block it will stumble and die after a block. It will restart with the choke and idle fine and get me back home. There are several ports on the carb that are open and some have rubber plugs on them too. This a relatively low mileage car, around 35k miles.

 

Those two lines are the oil metering g pump feed lines. Each connects to its respective nipple on the carburetor. The nipples are on the left side of the carb on the main body. Do not loop them together. They supply oil to the engine to help lubricate the apex and side seals and the are critical to the engine unless you are strictly premixing.

 

Thank you! I definitely need a diagram to show these connection points.

 

Foxed.ca - Mazda RX-7 Manuals

 

When I checked into this further. I noticed that the spare carb that I thought was original to the car and subsequently was rebuilt and installed in the car doesn't have the same number of ports as the one I removed. Is there a reference to know which carb is original to this car? The carb numbers I have as as follows:
210284-C32 the second line is 4 9 03 Z

The second carb is:
210284-721 and the second line is 4 03 Z

I would like to start with the correct carburetor reference point when I have manuals to consult. Thanks!

 

Can you show some pics of the carbs for comparison? Many guys here can identify them from sight and tell you which one is correct.

 

Oh, and here are diagrams of the vacuum lines and oil tubes.

 

Thanks! Here are some pics:

Carb A1- This is the better looking carb that I thought was original to the car

Front View A2

Side View A3

Rear View A5

Second Side A6

Second Carb B1

Front view B2

Side View B3

Rear View B5

Second Side B6

 

Someone has removed the nipples for the oil metering pump lines on the first carb. They are clearly seen on the main body of the second carb. I would rebuild and use the second carb.

 

Thank you I do see that the nipples are missing for the oil lines. That is why I began questioning this carb even though it looks like the original carb to the car. Do these ports pull vacuum?

 

I'll let someone else answer that question ("do these ports pull vacuum") but I want to reiterate what someone said earlier -
You NEED the oil pump plumbed into those ports. Running without the oil feeding them will result in damaged apex seals and scored rotor housings. Quickly. The previous owner may have been pre-mixing instead, which is fine. Its a PITA but it works. Don't drive the car anymore until you either start premixing or reconnect those lines.
Can you contact the previous owner and ask him?

 

The backstory is the original owner passed away and the car sat in the garage for several years. Hence gumming up the fuel system. The guy I bought it said he went to pick n pull and got a carb to put on while he was going to rebuild the original. That's where I entered the picture and bought the car. I havent been running this car except in the garage so hopefully its not damaged.

 

Just to safe safe, I'd drain the gas and put in fresh with 1.5 per gallon 2-stroke oil.

 

*1.5 ounces of good pre-mix oil per gallon of gas.

Personally I use 1oz/1gal for regular running but you don't know what's in the tank and the lines right now, so... better to go heavy.

 

It's handy that the fuel tank has a drain plug. I drained the fuel and replaced with new and flushed the lines. I will add oil to the fuel to be safe as well.

 

Sounds like you are on the right path. The oil metering pump lines are vital and can be brittle. Care should be taken when handling them as I believe one is NLA. Dkes your car still have the lines and the oil metering pump and rod in place?

 

Is this the metering rod? The oil lines look to be in good condition.

 

Wow. I couldn't figure this out at first since I was trying to download via Google and it wouldn't allow it. Tried the other way and it was like the clouds parted. Thanks!

 

Yes, that's the rod. On the carb's primary throttle shaft, that the primary (small) butterflies pivot on... on the end towards front of car is a mounting point for that rod end. It fits in a small hole, and moves up and down when the butterflies open. The further the butterflies open, the more oil it let's flow up the tubes and into the carb. The oil mixes with the gas and lubes the seals inside the rotor housings.

All this equals a happy rotary.

 

I was just looking for this info and had a pic of the routing from hood decal but wanted to know what each of the vacuum ports on the phenolic spacer were. Looks like #5 is just plain ole manifold vacuum, highh at idle noload and very low at WOT I suspect. Sorry to thread jack but this is good info. Max were did you get this drawing? I assume one of the 1st gen manuals.

 

t_g_farrell,
I just googled "rx7 vacuum line diagram" (images). I had to scan over about 20 FC and FD diagrams, but then the 12a's showed up. Most of the pics say rx7club.com or banzai-racing.com or mazdabg.com under them, so I'm not sure what the original sources were.