OK

Here I am, with this carburetor torn apart. It seemed a good idea at the beginning, but soon escalated into a pile of parts.
Never had a carburetor torn down. What an introduction to carburation!
However, as I have moved along, helped with some Youtube videos, I have managed to get it mostly together by a process of
elimination. Most parts only fit on one place.
Biggest issue plaguing me is the sudden appearance of two small springs similar to miniature pen springs, and the plunger
that goes in to bore for the main discharge tube. Not sure that what I have actually should be there. The "small pens springs" fit on the small part of a shaft that seems to be the correct part, but I believe the valve for the main discharge tube shouldn't have a spring in it.
Other than re-arranging the water choke linkage, I just may be able to get this back together in working condition.
The idle cutoff solenoid clicks, apparently the workings are internal.
The secondary diaphragm needs to be replaced.
The choke pull off diaphragm needs tobe replaced as it holds no vacuum.

Suggestions welcome for that mian discharge valve assembly!

Stan

 

I don't know if this will be any help or not, but a carb is a carb, essentially.
These pictures are from the 1985 FSM, buuuuuut...
BTW: Do you have the FSM for the year and model truck you have? It'd be a REAL good idea to get one.
Also, don't necessarily trust everything you see on UTube. It may well be accurate, and all well and good, but it may not. The FSM you know for sure is correct, yes?
Anywho, I hope these are some small help...




It looks to me that maybe one of your springs, at least, may belong to the "Power Piston, Jet, and Valve" assembly. I may be wrong, but that's what it LOOKS like to me.

Good luck to you. As an aside, can I presume you got a gasket kit for your carb before you began re-assembly? AND that you cleaned everything thoroughly with a decent solvent, or at least clean gasoline? Just wondering. Pretty important things...

Pat☺

 

NOPE no truck yet but still looking for a 1980 pickup....

One of the parts of the carb rebuild I am having trouble with seems to be depicted on the instruction sheet that came with the rebuild kit. And it seems to me.....

The control for the main discharge was jury-rigged to operate. The suspicious part was attached with sealant in the "up" (open) position, and apparently there were no parts beneath it (no check)
No wonder I can't find the parts. I didn't remember anything but the "nail-like" part that came out of the hole.
The drawing that came with the instruction sheet does indeed show a nail-like top piece, what would have been a small brass "sleeve" over the nail that probably rested on the ball at the bottom of the valve.
Now I need to find out which ball is correct. I can make a brass sleeve if I need to, but perhaps someone on the forum has one in their "mega-missing carburetor parts spares box" that I can buy.
I suppose I could make an overlength sleeve and shorten it if it doesn't perform as expected...

Thanks for posting the pics, it almost seems every carburetor was different-like the factory was changing it's design every Tuesday or something...


Cheers!

Stan

 

Found it
Kit manufacturer has the drawings online, but the kit didn't mention it.
Copied a bit of the image and will post here.
Parts 28- Washer, stopper
29- stopper, pump passage
30- weight,discharge ball
and
31- ball, pump discharge (big)

...are all in question.


Carb I am working on was missing all these parts, all that there was there was a part resembling # 29, only the one that came with this carburetor had a smaller shank continuing below the main shank. Might not even have been an Aisan part in the first place? I don't know. Just hoping someone as a sibling carburetor with a similar setup.
The way it arrived the "#29" was held in place with some sort of sealant- in other words-wide open at all times, and may explain how the throats were nice and BLACK, and perhaps why the original owner dicided to go with a Weber.

Thanks!

Stan

 

Good morning

I should mention that the hot idle compensator assembly on this carburetor was taken apart, cleaned and re-assembled following a forum post somewhere. But when re-assembled it didn't function- I put the whole assembly in hot water and the valve didn't open. So I re-assembled it once again, tested it, and it worked. Now I just wish the seal from the kit that goes behind the compensator was thicker. As supplied, the seal sits below the carb body, and provides no "seal".
Might have to get back to gasket and seal making as I did years ago!

Later

Stan

 

These arent the simplest carbs out there, so props to you for taking on the rebuild.

Out of curioisity, have you found and good seal/rebuild kits on the web?

Stick with it!

 

Hi there

I figured that somehow Toyota probably knew what it was doing with these carburetors. If I can locate the diaphragms and the correct valve assembly for this
particular carburetor, I will be quite satisfied.
I ended up with the Hygrade 739C kit; plenty to reassemble the carb, but still no secondary diaphragm, nor the parts needed to finish the valve assembly in question.
I suppose after 4 decades of rebuilds, and "experiments" etc., it may be a little tough to find a carb that is actually internally intact- but this was expected.
I can mke a brass weight for the valve, but knowing the OD of the weight is important; this I do not know. I do know that I can get tubing with an ID of 3/32 which will allow the weight to slide upward and lift the valve to open it. But if I don't have the OD, I won't have the correct weight. That is why I am hoping some hardy soul might have an old carb lying around (matching this one) that has the correct internal valve assembly. It is easy to cut small brass tubing, all it take is a fresh XACTO blade- lay the tube on a hard surface and roll it back and forth until you have cut through. 1200 grit sandpaper will deburr the bit you have made, being extra careful to deburr the ID so the piece is free to slide.
While waiting for more information I followed pinhead0001's videos as a basis for assembly. I assembled all I could without applying any torque and I found it is actually quite simple as long as you are willing to talk yourself out of how many parts you have laying in front of you!

Stan

 

There are people who know these well and rebuild them for fun, but as you've found, they're pretty complicated. I remember dealing with the carb on my 83. I found several diagrams online and in manuals but never found a single diagram that matched my carb. When my 78 needed carb work, I just bought a Weber and was done with the whole deal.

Good luck.

 

I havent seen him on the forums recently, but 13swords is one of the people to ask about these carbs

 

I've got a fresh 1980 Aisan carb rebuilt from National Carburetor that I could sell you for a good price.

http://www.nationalcarburetors.com/l...partnum=toy395

 

Hmmmm.....

The question I have is where do the get parts to restore to OEM specs? If they are getting cores, do they just take the ones with all the internal parts
present and intact? There seems to be many internal variations, with variable parts.
There are plenty threads regarding preformance related to the carbs, but they are like 4 decades old, and are like to have been subjected to "experiments" that may have ended with damaged or misplaced parts. Many go in as cores; how does one know these are good?
I just need to find one intact example, I can make the missing parts. I just need more information.
Besides, I have never touched a carburetor (maybe inadvertently while spraying Gumout) and it is one more item on my list to know more about!

Thank you for the offer!

Stan

 

A lot of people have good luck, but I had terrible luck with National Carburetor.

Their brand new rebuilt carb went in the trash and I put on a Weber and lived happily ever after. I was short on time they insisted it worked great, while the local carb guy found a giant vacuum leak that couldn't be fixed.

 

Like I mentioned above, it is probably precarious to offer carb rebuilding for these carbs just because you don't know what's inside the cores. For that matter, it may be likely that factory drawings of every iteration just doesn't exist.
This carb may have been rebuilt and sold with wrong or missing parts. If they are not avaiable, what do they do? It appears as if the valve was attached to the gasket above it with a dab of sealant, in the open position- and that just make it a little difficult to fully adjust properly!
The community should consider pulling together to try to de-mystify these things so folks will feel confident whether they are buying Aisan or Weber.
I really don't need much an excuse to buy a small lathe, and that I could use to make some "missing" carb parts (among other things). I may have to make the parts as I doubt seriously there is a stock of replacement parts anywhere.
And so my search continues for the true internals for this carburetor..


Cheers!

Stan

 

Carb still available?

 

Hi

As a matter of fact, the carb is available as I will need a full-sized truck to do the work I have before me.

Cheers

Stan