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Old Jun 6, 2016 | 05:17 PM
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Project Grandpa

Hello I was a little stupid on the intro portion of the site and began rambling off every discovery I had made on the car. I have decided to start a build thread. Today I went to pull a part and found the only SA they had.. Well in fact it was the only RX7. They had a gas tank but as advertised was punctured to dump the gas, which sucks but it was in way better shape than what was in the car. And it has a sender in it too. So I cut the belly out of the old tank and made a patch panel for the new/old tank. My harbor freight 90 amp welder sucks and doesn't get low enough to not burn through the metal. I have a friend working on it now. Once its done I will post pictures. Hopefully it won't be a loss. And on a better note I picked up a Nikki 30.00 too and 2 ignitors 5 bucks, what a deal. I do have a question about the Nikki though. The top where the primarys are id smaller than what the car has on it now. Could it be an older 79 carb?

I will probably go buy the 12a next week as well as the transmission. Since it appears I'm the only scavenger picking it apart. My cellphone died so I have to get a new one. That way I can take pictures of the updates and progress.
Attached Thumbnails Project Grandpa-sliced.jpg   Project Grandpa-repair-1.jpg   Project Grandpa-repair-2.jpg   Project Grandpa-repair-3.jpg   Project Grandpa-repair-4.jpg  

Project Grandpa-repair-6.jpg   Project Grandpa-repair-7.jpg   Project Grandpa-old-rusty.jpg  

Last edited by bpcZoD; Jun 7, 2016 at 11:35 AM. Reason: adding pictures.
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Old Jun 7, 2016 | 11:40 AM
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Also when out in the pull a part I took the carb off the car just to save it. Or sell it. Its different than mine I believe its for an 84 I'm posting pictures of it as well as mine. Mine is the first pic the other is the salvaged carb. Mine has bigger primary openings, so really not sure what year the other one is from.
Attached Thumbnails Project Grandpa-mycarb.jpg   Project Grandpa-carb-1.jpg   Project Grandpa-carb-2.jpg   Project Grandpa-carb-3.jpg   Project Grandpa-carb-4.jpg  

Project Grandpa-carb-5.jpg  
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Old Jun 7, 2016 | 12:00 PM
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84 Nikki
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Old Jun 7, 2016 | 12:12 PM
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That's what I thought... Thanks for the information. I will be going back for the engine and transmission as soon as possible. And the cool chrome Mallory coils
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Old Jun 10, 2016 | 04:58 PM
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Just picked up my carb rebuild kit. Ordered a clutch master and picked up a new fuel pump and filter. Hopefully I bought the right pump since they didn't have mine in stock I bought and after market pump. MrGasket brand 4 to 7 psi. If anyone knows before i install this thing please let me know.
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Old Jun 11, 2016 | 09:48 PM
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Today I put the gas tank, Fuel pump and rebuilt carb back into the 7 and got my own answer on the fuel pump. The Mr gasket pump had too much flow and caused the floats to open and it was just dumping gas... So I took the stock pump and ran it for 20 minutes in a tub of gas to make sure it was still good and clean it anyhow everything is good to go fuel wise.

I got the engine to run, however only when I pour atf into the carb. It will run but popping and missing I assume the apex seals are stuck or damaged.. So now I have to yank the engine and start the rebuild process. I did find another engine which im going to buy but its basically just a parts engine. I assume I will need stuff off of it anyhow. I only ran the car for a few minutes with the atf smoking like a freight train. My question is should I have ran it longer to get parts to free up?
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Old Jun 12, 2016 | 02:37 PM
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Update progress made.

Well she lives.. After some more messing around with the car I ended up doing yet another ATF treatment. This time I remembered to take a video. It seems I still have some carb work to do. For some reason the floats seem to be sticking causing it to overflow. Anyhow here is a video of it running after 20 years.
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Old Jun 12, 2016 | 04:04 PM
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ATF has no place in a rotary engine. You followed some bad advice.

The floats aren't sticking. My bet is the float bowl vent solenoid is not connected or is sticking. Or someone has been inside the carb at some point and replaced the good quality OEM needles and seats with garbage aftermarket needles and seats, and tried to adjust the floats to compensate, thus ruining the carb. Or not. I would have to see pictures to know for sure.

All that aside, congrats!
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Old Jun 12, 2016 | 06:01 PM
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Yea I saw that there were conflicting results and answers on the ATF topic. I just rebuilt the carb but not sure if I got everything cleared out. I thought at first the 4-7psi fuel pump might have been too much pressure for the needle valves thus the over flowing.
But with the stock pump it was more of the same.
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Old Jun 13, 2016 | 09:13 PM
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Took the carb back off today to see what i messed up.. I had the wrong gasket up top and i also had it flipped. Thats where all the gas was coming from. So now I have killed the battery because I didnt know the leading coil wire came off. So im cranking like a moron and killed the battery.. Its charging now and I think I have solved the carb issue.
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Old Jun 14, 2016 | 05:00 AM
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Nice progress! I think you'll get the carb issue sorted out easily enough. Lots of help here on the forum if you get stuck.

I never thought of repairing a junkyard gas tank! I've seen plenty split open but thought there was no way it could be repaired. What was I thinking?!??
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Old Jun 14, 2016 | 05:07 AM
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Originally Posted by woodmv
Nice progress! I think you'll get the carb issue sorted out easily enough. Lots of help here on the forum if you get stuck.

I never thought of repairing a junkyard gas tank! I've seen plenty split open but thought there was no way it could be repaired. What was I thinking?!??
Really didn't have a choice other than a fuel cell. I have put about 5 gallons of gas in the tank and not a drop leaking out. So I think my gamble paid off. Hats off to my friend on the leak proof welding. I initially cut out a patch from the old tank but it was so thin from all the rust it was not a good candidate for a patch.

I have a picture here of me pointing at a nozzle of some sort. I can't find any info on it. Also I took a picture of my brain fart.
Attached Thumbnails Project Grandpa-img_0083.jpg   Project Grandpa-img_0086.jpg   Project Grandpa-img_0087.jpg  

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Old Jun 14, 2016 | 04:19 PM
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The nozzle you are pointing to is for the subzero fluid. It had a TSB and should not be used. It doesn't need to be capped as it has a spring loaded checkball inside and won't leak. Just leave it alone.
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Old Jun 14, 2016 | 08:26 PM
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Well damn... I'm having issues with the carb. High idle running like crap and spitting gas drops out the secondaries. It ran better before I fixed it. lol I took it back off today and checked the floats. I think the little retainer clips were causing it to hang. I took them off now they function as they are supposed to. But I can't figure out why its running totally different now. I mean besides the spitting fuel in the secondaries and now the high idle its just plain weird. I forgot to count the turns on the MAS and the one below it. The sorenson kit says 4 turns out on the top one and 2 turns out on the bottom one. The two circled in red.
Attached Thumbnails Project Grandpa-img_0082.jpg  

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Old Jun 15, 2016 | 03:17 PM
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Yep, you might have a vacuum leak.

Also you might have a stuck float bowl vent solenoid.

And those air and fuel screws can give you fits if you don't know how to adjust them. Others who know more about SA carbs that are stock or similar to stock could offer advice on them. All of mine have been modded and I adjust them until it runs good. Like riding a bike. I can't really describe the process I use in words.
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Old Jun 15, 2016 | 04:43 PM
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The large screw is the "air" screw. It's a controlled vacuum leak.

The small screw is the "fuel" screw. It's a controlled fuel leak, lol.

Adjust the air screw in to lower idle, and out to raise it. Adjust the fuel screw to change the a/f ratio at idle.
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Old Jun 15, 2016 | 05:45 PM
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Originally Posted by wankel=awesome
The large screw is the "air" screw. It's a controlled vacuum leak.

The small screw is the "fuel" screw. It's a controlled fuel leak, lol.

Adjust the air screw in to lower idle, and out to raise it. Adjust the fuel screw to change the a/f ratio at idle.
Awesome thanks. I was looking at the carb manual and needed to get more into it. On a different note when I sat the carb back down on the bolts it seemed to rock back and fourth a little. Almost as if a hose was stuck between the black plastic piece and the throttle body. I assumed that rocking was the source of the leak. However I couldnt find anything stuck between the black plastic thing and the tb. So I wonder why its rocking? It should sit flat with no wiggle, right?

I will take it back off yet again. And see why its not setting on the intake flat. And I guess I need to go back into the air horn and see whats up with the damn needle valve again. I saw a guy on youtube take a q-tip and stick it in some metal polish and then run it inside the seat with a drill and polished it smooth. I may think about doing that. As well as polish the needle valve outer part.

Last edited by bpcZoD; Jun 15, 2016 at 05:53 PM.
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Old Jun 18, 2016 | 10:26 PM
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Ok today i picked up the 12a from the pull-a-part. I noticed the timing was all boogered up. They had the leading coil wire hooked up to the trailing and the trailing hooked up to the leading. Then they also had the dizzy way out. I think whoever had the car didnt have a clue as to the timing of these engines. Anyhow On to the engine. The irons on this engine look like fresh clean metal. Almost like a set of rebuilt heads. No rust just like new metal. The engine rotated and wasn't stuck. Seems to have good compression. Paid 235.00 for the engine. The former owner looked like they gave up on the car. Nothing as far as vacuume was hooked up and everything was missing. Ratnest gone, Smog pump gone and a plate made for the intake to cover the hole when they took the smog stuff off.

Here are a few pictures I'll take better ones later. Dont know why the pictures are showing up sideways.. They are upright on my computer.. Weird...
Attached Thumbnails Project Grandpa-img_0106.jpg   Project Grandpa-img_0107.jpg   Project Grandpa-img_0108.jpg  

Last edited by bpcZoD; Jun 19, 2016 at 04:18 PM.
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Old Jun 19, 2016 | 08:54 AM
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Nice find! Around here 12As are hard to find in the junkyards. They don't come up often, and when they do it's like seagulls on a french fry.

Anyway, it's always good to save them.
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Old Jun 19, 2016 | 04:11 PM
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I have a few pictures of the intake and need a couple questions answered. If anyone can assist that would be awesome. This is the Junkyard 12a not the one in the car.

Here is the picture of the intake and the black plastic thingy. The gaskets I have do not match the holes in the intake and or the plastic thing. Can i punch out the holes to match the intake and "BPT" black plastic thing to make them work.

I didn't take the original gaskets off the intake or the black thing they were already gone.

I figured it out. I took the gasket seen in the 3rd pic and made the holes in it to match the holes in the first 2 pictures. Then i found the gasket for between the black base and the throttle body. I have it all sorted out now. I think.

Any suggestions on the two oil lines that go to the carb? They are both missing from the engine, also the vacuum advance hose is missing from the y. Can I just take it to one of the ports on the throttle body? I saw in the rat nest delete tutorial to take it to the 4th port from the left. Just want to make sure that's correct.
Attached Thumbnails Project Grandpa-img_0114.jpg   Project Grandpa-img_0115.jpg   Project Grandpa-img_0116.jpg   Project Grandpa-img_0117.jpg   Project Grandpa-img_0118.jpg  

Project Grandpa-img_0119.jpg   Project Grandpa-img_0120.jpg   Project Grandpa-img_0121.jpg  

Last edited by bpcZoD; Jun 19, 2016 at 10:04 PM.
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Old Jun 22, 2016 | 05:04 AM
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OK finally got the carb sorted out on the original engine. Turns out I must have used every wrong gasket when building the carb. I fixed the gasket between the air horn and the bowls. But the high idle was still a problem. I took the carb back off and apart found that the gasket between the bowls and the throttle body was the wrong one too. The gasket was covering a small hole near one of the bolts that I didn't see before. I changed the gasket and its now fixed. The car moved under its own power for the first time in 20+ years and I drove it into the garage.

Next items on the agenda are compression test, exhaust and then brakes. I watched a video about using a piston style compression tester I assume it will work once I take the shrader valve out. Anyhow It seems like it runs a little weird. And I found the oil leak the original owner said was the reason they parked it. The oil leak is between the front cover and the first rotor housing.
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Old Jun 22, 2016 | 06:37 PM
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That's a semi-common dowel pin o-ring leak. The engine sat for 20 year? Yeah. Only fix is a gasket kit and some time. Don't use magic potions or JB weld or anything stupid like that. Tear down + rebuild time.

Oh and a 13B from a 2nd gen with EFI swap is not the answer.
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Old Jun 22, 2016 | 08:30 PM
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Originally Posted by Jeff20B
That's a semi-common dowel pin o-ring leak. The engine sat for 20 year? Yeah. Only fix is a gasket kit and some time. Don't use magic potions or JB weld or anything stupid like that. Tear down + rebuild time.

Oh and a 13B from a 2nd gen with EFI swap is not the answer.
I have a 12a that has good compression. I'm going to swap them this weekend I'm going to post a video of how it runs now. I believe the rear rotor is dead. Its missing as if a cylinder were dead in a 4 banger. Sounds funny to say the least. I have spark on both the leading and trailing plugs. I know its not ignition. The engine is real easy to spin by grabbing the pulley and turning it. Thus making me think something is wrong. I will, once i get some money together buy a complete rebuild kit from Atkins. I've never rebuilt one but it doesn't seem to be too bad as long as you can crack that huge nut on the flywheel. I forgot to grab a compression tester so I will have to do that tomorrow. I guess its possible i hosed up the carb somehow and thats why its running weird. But I went back through the entire carb. Cant figure out why it would make it run like it is now.


Last edited by bpcZoD; Jun 22, 2016 at 08:54 PM.
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Old Jun 22, 2016 | 08:40 PM
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The nut on the flywheel is easy. I'm worried about the 19mm bolt on the front.

Yes, Atkins 12A apex seals are the answer when your rotor housings are missing chrome. They will break in on anything.
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Old Jun 22, 2016 | 08:41 PM
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You gotta love the 30 pound boat anchor flywheels they used in the SAs.
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