Solex 4a1 woes

[jack.stew48]

hello all!
ive got a beautiful Mercedes 280 which has been sitting for almost 20 years. its been under cover so it is still free of rust, and the aesthetics are in good shape, however the carb has been destroyed. when i got to it the carb was full of mouse droppings and leaves.. those are now gone. everything seems to be ok except for the four plates at the bottom of the carb, just above the manifold, are stuck. i got the two larger ones off of the rotating shaft, but i still cant manage to move the shaft like it should be. i fear that the carb is warped and that has caused it to seize.

my only experience with carburetors is one barrel vespa carbs so any and all advise is helpful, thanks

[Frank Reiner]

j.s:

With all respect, given your limited experience, it may be in order to have reconditioning work done by another. And, without the least bit of shame, I offer my services. I have experience with the 4A1, and have a spare carb, that along with yours, will most likely yield a working example.

[Mike D]

Take Frank up on the offer. You do NOT want to mess with the 4A1 carburetor. Without having the experience required you will do more damage unintentionally.

[JeffreyNMemphis]

The Solex 4A1 carbs can be warped if tightened excessively. The metal is soft. When the 4A1 carbs on Goldie Locks were rebuilt, my friend Don used a straight edge to verify that there was a warp, and to what degree it was warped, and where is could be persuaded to move back into straight lines. He heated and cooled the carb in cycled while adding pressure to the area that required an attitude adjustment. The outcome was a Solex 4A1 that was not warped and worked perfectly.

This carburetor rebuild was far beyond my skill set. I am grateful for friends like Don.

[jack.stew48]

Originally Posted by Frank Reiner

j.s:

With all respect, given your limited experience, it may be in order to have reconditioning work done by another. And, without the least bit of shame, I offer my services. I have experience with the 4A1, and have a spare carb, that along with yours, will most likely yield a working example.

i would definitely love to take you up on the offer, seeing as my lack of knowledge will simply lead to bigger problems down the road.

Jack.

[Clarion]

I also have a '73 280C with the Solex. I also have an'83 380SEL v8 for parts. Are the carbs interchangeable? Also looking for the '280C' emblem for the trunk...mine escaped...

[DieselPaul]

The v8s are all fuel injected.

[JeffreyNMemphis]

The Mercedes nomenclature is that S is SonderKlasse (special), E is fuel injected and L is Lang (Long wheel base).

[Larry Delor]

I had to deal with a 4A1 once... Not my favorite carb. Pretty sure that the mouse droppings were the opinions of the mice that found it. Good luck with that thing

[Mark DiSilvestro]

I suggest applying ATF to the shafts and working them till they loosen up.
Otherwise that Solex will be an expensive animal to replace. There's also an outfit called Jam Engineering that sells replacement carbs for Mercedes, but they're pricey too.
Or you may be able to substitute a Rochester Quadrajet, as used on GM V8s in the 60s and '70s. I saw one installed on a '79 grey-market BMW 6-cylinder coupe many years ago, that had originally had the Solex. Having worked on both carbs, I'd swear the Solex is a knock-off of the Rochester. But I don't know what jetting or adapting would be needed to fit a Quadrajet in place of your Solex.

Happy Motoring, Mark

[Mike D]

The Solex is indeed a copy of the Rochester carb. In fact, Solex manufactured them using a Rochester license.

Unfortunately the Q-jets suffer from the same warping problem as the 4A1's. Most of the ones you find at the U-Pull-its are warped beyond use. 80% of them can be straightened but it's a time consuming process involving ovens, press tables and jigs. The Q-jets are no longer manufactured but Edelbrock makes a copy.

Just installed a factory authorized rebuilt (the ONLY way to go on the Q-jet!) on a friend's GM product. $375 US.

I believe I have a write-up on this board about my carb swaps. Tom W. posted the jetting for his Q-jet swap also.

[Mark DiSilvestro]

Originally Posted by Mike D

The Solex is indeed a copy of the Rochester carb. In fact, Solex manufactured them using a Rochester license.

Unfortunately the Q-jets suffer from the same warping problem as the 4A1's. Most of the ones you find at the U-Pull-its are warped beyond use. 80% of them can be straightened but it's a time consuming process involving ovens, press tables and jigs. The Q-jets are no longer manufactured but Edelbrock makes a copy.

Just installed a factory authorized rebuilt (the ONLY way to go on the Q-jet!) on a friend's GM product. $375 US.

I believe I have a write-up on this board about my carb swaps. Tom W. posted the jetting for his Q-jet swap also.

I wasn't necessarily suggesting a USED Quadrajet. But I'm sure that $375 rebuilt is a lot cheaper than what the Solex would cost!

Happy Motoring, Mark

[BWhitmore]

Edelbrock no longer makes the Quadrajet type carburetor, however both new old stock and rebuilt Edelbrock quadrajets show up on Ebay at times. The other problem with the GM quadrajet was the main well plugs leaked which resulted in the carburetor running out of fuel. The cure was to epoxy the main well plugs in place.

[Adler]

Most mb Solex and zenith carbs are prone to warping and extremely difficult to correct, Weber replacements are a much better option from jam engineering.