Oh no, my carburetor rebuild.

[asianwills]

This is gonna be a journey lol. I hope I’m not too annoying but I’m probably going to have a few questions. Kinda want to make this to get some answers, but maybe to also help others who have the same monkey brain as me.

First monkey brain move was thinking that these lines were like the other vacuum lines. Turns out they are not, and instead some sort of plastic lines, caused they snapped right in half. This is the front of the carburetor going into a secondary solenoid and somewhere in the front. The two lines split at a 3 piece connecter. I just need to replace the two going into the carburetor. Anybody got ideas how to fix/replace this, can I just use normal vacuum lines?

(The two places with green masking tape.)

[Jamnar_V]

The old rubber vacuum lines will get brittle with age - very common back in the day to have this happen.
Carefully chip/scrape away whats left of the vacuum line from the fittings and replace with a section of new line and it should be good.
The plastic tee will be the next thing to shatter with age. Be prepared for that.

[asianwills]

Ok, I got it out; it wasn’t too hard. Before I start taking it apart though, what are all the torque specs. My manual doesn’t show any, at least from what I’ve looked at. I’ve tried looking online and at some other forms too, but still can’t find any. Do the torque specs matter, or are there any?

Also what are the benefits of a vacuum delete? Are they risky, and how hard are they too do?

And then, is it even worth fixing my keihin? Or would it be better just do get a new one? Like I’ve heard a lot of people put in webers, what would be the benefits to that? And how hard would that be? Thanks!

[Dr_Snooz]

The Keihins are kinda notorious for being difficult. The Weber is an attractive choice if your smog laws allow it. The only torque specs that I'm aware of are for the mounting nuts.

[ShiRen]

The torque spec is: dont strip out the screw heads. They are soft JIS screws, not phillips, so you can easily strip the heads, but its not like you can go that tight, you have more of a chance damaging them when removing them. If you want to go it right get a screwdriver like this https://www.amazon.com/Vessel-Megado...5-56d755c862ba

The vacuum delete is extremely worthwhile and you get a lot of power and throttle response in return, as well as a lot less complexity. On the flip side the car will be a lot more cold natured, no more idle control, you set the base idle as high as it needs to be without stalling when you turn on the AC and head lights, and you might have to make tiny adjustments over the year. The weber is better, but vacuum delete is free. Check out the guide here and as questions. https://www.3geez.com/forum/showthre...elete-pictures

[Dr_Snooz]

OP indicates he has to pass smog tests.

[ShiRen]

I didnt see where he said that. Honestly though, if you only have to get the tailpipe sniffed and mods dont really matter, I wonder how hard it would be to just fiddle with the ignition timing to get it to pass. Common rx7 thing

[asianwills]

Sweet, for some reason I wouldn’t have thought that this could be a long lasting mod. And it sounds like if I need to do another test, then I could probably do things in order to get it to pass. I am most likely going to do this rebuild and then do a vacuum delete. Wish me luck.

[ShiRen]

Take the time to learn what is going on here and expect the car to require some fine tuning, but right off the bat, if it isnt running good after the mixture is set something is wrong. Once the delete is done you should be left with a simpler and easily tunable car, but you have to know everything you are doing. This is mainly spark timing, idle setting, mixture setting, float setting, and accel pump setting.

[asianwills]

I have made some progress, including taking of the air horn assembly and taking off parts on there. (like the needle assembly and power piston assembly) I’m planning on cleaning things when I’ve got things into pieces, tell me if that’s dumb.

The screw driver ShiRen had sent is helping a ton, everything had been coming off really easy. And if it is a little bit more tough then it is able to grab it and get it, I really like it. However one of the four screws on the bottom of the throttle body assembly connecting to the main assembly is insanely tight. But the other three screws came out way easy with the screwdriver. I am resorting to a screw extractor, hoping that I don’t destroy anything else with it.

Luckily, I have found a replacement screw. Here is a link to one if anybody else needs one, https://www.partzilla.com/product/ho...oCnDsQAvD_BwE#

In the carburetor rebuild thread, there was talk that if you flip over your carb then it is dead. That was later fixed saying that it is ok flipping it, I just wanna make sure that is still true. (it’s making me nervous)

Also, are there places to not spray carb cleaner/brake cleaner, or things to be cautious when cleaning? Is brake or carb cleaner better?

[Dr_Snooz]

I use a pan of Purple Power and a parts brush for cleaning. Berryman's Chemtool dip is great if you have a liver transplant handy.

Those screws on the bottom are #3 Phillips and they like to seize. Make sure the screwdriver is perfectly plumb, then bear down hard while turning until they break free.

Remember that a vacuum delete is altering the OE smog equipment on the vehicle, which is a federal crime. You will have to sneak the alterations through every subsequent smog test (not likely if there's any kind of visual inspection) and there will be an awkward conversation when you go to sell it. Lots of people do it and never go to jail, but you should still be cognizant of the waters you're swimming in.

[ShiRen]

I have no idea why the said not to flip it, Ive flipped mine numerous times and I don't see an issue. Don't think I have ever taken the throttle bodies off though.
I could have listed the impacta version of that screwdriver, you can hit it with a hammer and it spins. https://www.amazon.com/dp/B003BI8HHQ...&sprefix=vesse here it is if you want it. You can try a phillips impact driver at least to put some shock into it. Put some pb blaster on that screw for a day and if that doesnt help try some heat, not a lot though. Unless the screw extractor worked, I don't see a problem with that either.
As for solvents, I would just take off all the diaphragms off first, the rest should be fine provided you arent spraying it on any gaskets or anything you are trying to reuse.

[asianwills]

I haven’t had much time to work on the carburetor for a bit, but I was able to take off some more of the diaphragms and whatever. I have a few questions though. In my carburetor rebuild there is not a replacement diaphragm for the throttle controller, and this is what my current one looks like:


It is cracked open on one side and there are two small holes in it. I was thinking I could use just a little bit of super glue to glue it down, but I don’t know if those small holes matter?

My other question, how do you get the fast idle unloaded diaphragm off? Unlike other linkages, linkages on and around the choke housing have different plastic pieces holding the rods in. I can’t get the rod on the diaphragm disconnected to replace that diaphragm, other linkages just have a cotter pin. I will include a picture on the next reply:

Edit: Also, I’m a little bit confused about the cut out paper gasket. Do I cut one out and put it under the carburetor and on top of the EFE heater, or under it? Because there wasn’t one there when I took it off.

[asianwills]

Red: Diaphragm I want to replace
Blue: Linkage I can’t get off

[Dr_Snooz]

I wouldn't take those vacuum actuators apart unless I had to. No kit will include replacement diaphragms and, since you're working on a museum piece, any disassembly risks destroying the part. Simple disassembly is going to put a lot more stress on them than normal service, so just leave them alone. Use a vacuum pump to test them, or even just push the rod in, and with your finger over the vacuum port, see if they stay down. If they hold air, leave them alone. I tried patching holes like yours with RTV silicone gasket maker years ago. I'm not sure how it worked out, but I didn't notice any problems in my daily driving after the repair. The RTV is durable and very tenacious on the right surfaces. Keep your patch thin so it remains flexible.

[ShiRen]

Uh yeah you absolutely need a gasket between the carb and heater... You may have just found the source of your problems.

[asianwills]

Well I mean there is this small rubber gasket on the heater, but from the other forums it’s sounds like there is supposed to be another one of paper on top of it.
Edit: I haven’t heard much about that rubber gasket. My rebuild kit didn’t include one either.

[asianwills]

Crap, I’ve messed up. A ton of my coolant has been leaking. It’s hard to tell where it is coming from. Because on the picture it looks like it is leaking from the heater, but I wasn’t having any problems with leaking there before taking of the carburetor. I don’t know how taking of the carburetor would cause that problem. Because of that it leads me to believe that it is leaking out of that small hole, but I don’t know how it would go against gravity and come out of that hole either. What should I do?

[ShiRen]

It is unlikely that the rubber gasket can do its job, a paper one works very well.
As for the coolant, I am afraid the easiest solution would be to delete the coolant lines off the intake, all 3 of them, loop the main 2 and plug the middle. That hole has pressure coming straight from the water pump. Unless you deal with weather often below freezing, but I have not had any cold weather issues without coolant on the carb and intake, its just a point of failure as we see here. I have been afraid of removing the heater block because they are very stuck on the surface of the manifold, if you do get it off without breaking it I am not sure what the best way to seal it again would be. Paper gasket? Silicone? And if it is leaking coolant I would be afraid of it also being a vacuum leak.
And I do not think you have messed anything up, but you definitely need a paper gasket under the carb, if anything it is an upgrade.

[asianwills]

I don’t have any gasket material that was there before to compare it with, but is this stuff good for the bottom of the carburetor?
https://www.amazon.com/Fel-Pro-3157-.../dp/B000CNISM2
It is 1/32” thick also .08cm thick.

Also, it might just be my phone and how I’m using the site, but are the pictures in “Carburetor Rebuild , Top Gasket Printout / Other Gasket Info” gone for you guys too. Those would be some nice pictures, he also talks about a printout he had made.

https://www.3geez.com/forum/showthre...er-Gasket-Info

[ShiRen]

Yes, that will work great.

Yeah, all that stuff is gone, I havent had any issues reusing the top gasket, but if yours is too far gone just push the paper against the carb and tap it with a hammer to get the outline, it would be good if you had an old top gasket for reference.

[asianwills]

For a while I’ve been trying to figure out what to do. My choke opener and idle control diaphragm won’t hold vacuum. I checked both and they both definitely have holes in them. I have a feeling that this could explain my stalling and delayed throttle. I was able to find a choke opener in stock, but it comes with the whole assembly that I don’t need. (and is $60+) On the other hand, I can’t even find an idle control. It says it is discontinued. It really really bugs me to leave things that I know aren’t working properly, but maybe that’s all I can do. Any thoughts?

For the choke opener diaphragm, I have an identical one that I am not using. But I don’t see a way to transfer that over.

Edit: My rebuild kit doesn’t have any of these diaphragms. I don’t know why. Especially that the ones that I’m replacing don’t need it, and the ones I need I don’t have.

[ShiRen]

Ebay? Parts yard? Idk, I don't even have a choke and it runs fine this is why I don't like anything extra that can leak vacuum.

[asianwills]

Update: So I bought the diaphragm that I was able to buy off of HondaPartsNow. Then on the other diaphragm I was able to coat a thin layer of black adhesive sealant from Permatex with a paint brush. It actually worked pretty good, it holds a vacuum now. It is also very flexible still, I would recommend doing it if you have the same problem.

I got the carb back together and now am just working on the base gasket. I tried kinda guessing and checking with a paper trace, but I don’t think it worked very well. Does anybody have the pictures of the gasket from this thread. Or the correct scaling from a different picture to print of the right size?

https://www.3geez.com/forum/showthre...er-Gasket-Info

On that same thread it also talks about two different versions of the gasket, one with the accelerator pump bleed hole and one without it. Why would you want to block this, what would it do?


Sent from my iPhone using Tapatalk

[ShiRen]

Are you referring about the top gasket that seals off the float, or the base gasket that seals the carb to the intake?