One task of the body shop team is to clean the heater cores and pressure-test them (for leaks). So it was about time to remove them from my two heater modules. As you can see, the first one was quite rusty, and what you cant't see is that that big middle plastic piece was molten in some areas, for whatever reason.

There is plenty of surface rust inside, but nothing that can't be fixed with a bit of sandblasting and some fresh layers of paint. Those springs and mechanical parts will be a bit more tricky to replace, but I'm sure there is a solution.

Luckily, I have some parts replated already, which will definitely be helpful to restore this thing.

Completely disassembled. With plenty of rust and dirt who fell out of the box:

While at it, I thought I better take apart the second one too, which was visually in much better condition (except that tacky wiring job).

All controls, wires, and plastic pieces removed:

I was struggling to remove one of the hoses, and it needed replacement anyway, so I took out my trusty garden-hose cutter (from a gardening project). Ah, sometimes it's nice to have all those special tools on hand :-P

After all the screws were off, I was finally able to remove the second heater core.

The second box was indeed in much better condition. the yellow zinc parts are corroded, but still visibly yellow. And It had all the original stickers, quality stamps and part number stamps on it:

I'm not an expert when it comes to these things, there is corrosion and parts of the paint peeled off when I vacuum-cleaned the dirt of the heater cores, but otherwise They were much better than what I expected. I hope a professional wash will make them look shiny again.

During some recent work, I realized that the first body shop has accidentally closed two of the VIN-tag plate holes. But instead left a new one.  So it was time to get those missing holes back in:

Here we go: Yes, one screw was missing (new ones are ordered) and the plate itself needs to be redone, as one corner broke off when I removed it years ago, and then I want to have a nice and shiny one anyway. Luckily, good replicas are available, and all you have to do is to stamp back the numbers. I also double-checked if the engine is still an original "Matching numbers" engine, and yes indeed, I still have the correct engine for this chassis. Which is great :-)

Plenty of other works and updates going on in the background, so expect more updates soon.

As usual nice stuff Nils!

I would consider using these throttle spindle springs that go between each carb choke on the throttle. I use them when I rebuild Mikuni PHH's.

https://www.jauce.com/auction/k1231660176

They give a bit more resistance when the throttle shaft moves and thus feel better whilst driving.

Cheers

Ian

14 minutes ago, RIP260Z said:

As usual nice stuff Nils!

I would consider using these throttle spindle springs that go between each carb choke on the throttle. I use them when I rebuild Mikuni PHH's.

https://www.jauce.com/auction/k1231660176

They give a bit more resistance when the throttle shaft moves and thus feel better whilst driving.

Cheers

Ian

Hey Ian, Thanks for the Input, as always. I just spent a fortune on PHH spare parts, but this spring is new to me.
Do you have any photo of them installed, just so i undestand where they go exactly? Quite curios, but sounds like a great idea.

Hi Nils,

Photo shows spring on shaft, the hooked end goes in the original position on the aluminium pump rod actuating arm thingy, and the straight edge goes against the side of the carb housing. And the is just a photo of my resto work on these Mikuni carbs.

5 minutes ago, RIP260Z said:

Hi Nils,

Photo shows spring on shaft, the hooked end goes in the original position on the aluminium pump rod actuating arm thingy, and the straight edge goes against the side of the carb housing. And the is just a photo of my resto work on these Mikuni carbs.

Lovely, thanks a lot.From what I can see on the photos, my carbs came with this spring? But they look grey and old, so i ordered a new set since i've made a big order anyway. Cheers!

So, my Carb guy started to work on the carbs and sends me regular updates. First  he dismantled everything. Some bolts were glued in by the previous owner and it was quite tricky to get them out:

He checked and measured each individual component to see the state. As you can see some parts were bad, despite looking good. For e.g. this butterfly / throttle body shaft was bent and requires requires replacement

https://www.jdmjunkies.ch/wordpress/wp-content/uploads/2026/06/Throtthe-shaft-bent.mp4

One everything was dismantled, it was time for a a bath in the ultrasonic cleaner:

The internals came out beautifully, but we realized that the jetting is wrong for the L24 engine on some of the carbs.

Some bodies show heavy signs of corrosion after the bath:

Once he removed all the corrosion and cleaned everything, they turned out like this:

here is a better photo: Before assembly, the parts will get an additional glass-bead blasting for a smooth and tight surface: 

I also got an order list and was busy ordering small bits and pieces. The first ones already showed up, but I still have a few orders pending:

In case you're wondering: We used this referance table from upgrade motoring for the jetting of the carbs. At least as a starting point.

Edited June 24Jun 24 by JDMjunkies.ch

What method did he use to clean the corrosion off the carb bodies?

46 minutes ago, Patcon said:

What method did he use to clean the corrosion off the carb bodies?

I asked him the same question: He said he used a Dremel tool and manually removed everything with different Dremel tips, like small wire-wheel and sandpaper-tip tools to carefully remove everything. Tomorrow the parts will additionally go for glassbead blasting (will smoothen and tighten the surface density, to avoid easy corrosion in the future).

Another option would be a surface treatment with head and some kind of annodizing, from what i understoud. this would give the carbs some kind of blueish hue, but make it even more resistant against corrosion. He did this on these sanyo-kikis.
It looks much less blue in reality, but you get the idea. It's not my cup of tea, so i won't do that, to keep it close to the OEM looks:

Look up M539 Restorations on YouTube, he restores and refurbishes BMW’s to absolute factory or better then factory spec. He uses a water blasting machine (I’m sure there is a better term for it) to clean all the parts and mainly aluminum engine parts. I’m not sure what exact product he uses afterwards but after basting he brushes on a protectant on the aluminum parts to keep them from corroding over time.

Give it a look, I’m sure it would be a great product to help protect your carburetors.

10 hours ago, Mitchel0407 said:

Look up M539 Restorations on YouTube, he restores and refurbishes BMW’s to absolute factory or better then factory spec. He uses a water blasting machine (I’m sure there is a better term for it) to clean all the parts and mainly aluminum engine parts. I’m not sure what exact product he uses afterwards but after basting he brushes on a protectant on the aluminum parts to keep them from corroding over time.

Give it a look, I’m sure it would be a great product to help protect your carburetors.

Thanks for the hint. I'll have a look 👍

I spent more days digging through all my collected parst and boxes, and getting stuff organizied for the final phases of the project.

And then realized that I still need to replate many of the original fasteners. Since I mostly have 2 or more pieces of each item, which I need, I decided it's better to also disassemble the spare units and take loads of pictures. this will help me put everything back together later, but will also allo wme to have nice spare-parts ready or make one-out-of-two, and so on. So i spent the recent days disassembling loads of stuff:
Like the master-VAC / Master brake cylinder and brake balancer:

after:

Clutch slave cylinder.

Naster cylinder:

OEM brakes:

All of them disassembled:

Alternator. I don't know what happend to my car before. it appears like there was an oil explosion at some point. ALL of the engine-compartment parts have a thick layer of black greasy (oily?) coating on them. Before:

After. I didn't want to go further to not damage anything that doesn't need repair, but wanted to do this to get some parts replated:

Fan, Clutch and water pump pulley. As you can see, I also took the opportunity to find the correct parts that I had collected over the years and store them in the same box now. That makes things so much easier:

Thermostat / housing:

Disassembled:

Some parts were pretty heavy corroded (including holes). luckily I was able to find spare parts for many fasteners and small bits in my collection: Like this thermostat hose adapter:

Engine water piping (from two cars):

Again, i have plenty of new stuff on hand: It's so much fun to find all the correct little pieces:

Sometime sit raises some questions too. One of my cars had a water pipe piece that missed that little Y-pipe joint. A bit of scratching and I quickly realized that someone had weld it shut in the past. And of course that weld rot away, so there is a hole now :-)

I did a lot of other work as well. wait for tons of new fasteners, I removed some tomporarly installed parts from the car, I'm selecting different items from my stock to be installed on my car, I'm discussing with the zinc-plating companies, as it's a bit tricky (Chrome 6 is prohibited now, which was the previously used yellow plating, but there are solutions), and there is so much more. Despite the lack of daily updates, I'm spending many hours in the workshop every day and it's very rewarding, to say the least.

I'm having a bit of a good momentum, lately. So I've decided to take advantage and continue dismantling things. The reason I take everything apart atm, is that i plan to have all parts cleaned and zinc plated at once soon. So I have everything ready for assembly when the other parts are ready. It also gives me the opportunity to check all the various parts in stock. Go through my parts in the "random parts" boxes and sort them into the correct boxes, and so on. Some of the shown parts will only be spares, as I have new / restored parts in stock. but it's always good to have a selection to choose from:
First: The dashboards:

Tension rods:

Propeller shaft and drive s hafts. I will leave the greasy part to the specialists, here. As you can see, every single part on one of my cars suspension have ben taken apart, painted red and been assembled again. mostly with the wrong fasteners. makes it quite fun to puzzle it all back together. the good thing is that I often have a second set where many parts are still original. And then I have a big box with random re-plated fasteners which I bought from someone a while ago. And many of them appear to be the correct ones for various areas of the car, for e.g. these shiny replated bolts and nuts on the left for the drive shafts.

Hand brake assemblies (Sorry, no fance photo):

Hood release cable:

Wiper linkage and arms. I went the extra mile and took apart the whole assembly. you can see everything on my car is heavily corroded. And those clutch springs are broken. I'll make a special post dedicated to those springs and its function. I have ordered some generic spring steel wire and I hope I'm able to reproduce those myself.

Starter motor. Well I did this one more out of curiosity and because I had three of them, one in very rough shape. This one is clearly beyond repair, all internal parts are heavily corroded and rusted. I'm sure it would still run, but it's not really safe. I will have the easy replacable parts re-plated anyway, just in case. It could be remanufactured / refurbished, but since a new hitachi starter is only about 120 bucks or so, it's not worth the effort only to have a very old starter that looks good but doesn't work properly, or will fail after a while. 

None of my cars came with red interieor, so I'm not sure how these sun virsors ended up in my collection, but it was good to take them apart for spares.
I had to cut the foam / vinyl open on one side, to understand how the L-brakets can be removed. The factory design is quite a bit ingenious on these. Also note the glue on the vinyl. I guess these might come from my first, white car where the whole interior was covered in blue plush fabric, when I bought it. That should have been a sign to NOT buy that car. I learned my lesson lol.

And then, finally, I was able to find that one missing service bulletin for my collection:

Whlie it looks like I only took apart things and put them back in storage, it's only half the truth, I plan on ordering plenty of spare-parts, have the first orders on the way and also plan a lot of follow-up work to restore individual items. Etc. Also I have planned a special visit tomorrow, so stay tuned for more updates, soon!