solex 4A1 overhaul

[e21manic]

hey there guys,since not many build thread on e21s thought i wud share what DIY i have been up to..over the merdeka weekend was preety free so i took apart the carb from the e21. had problems idling and accelerating was as good as useless as i floored it and it didnt move much.. when taken apart,was shocked to see the butterfly for the bigger barrel wouldnt open when i pushed its lever. and the jets were all covered in some weird clay-ish type thingy. even the diaphragm had this clay-ish build up around it. nowonder couldnt get any proper idling and and high revs from the engine! even found a small leaf cloggin the fuel filter! what the?! wonder how the car ran with the previous owner..:stupid:haih.. so i took it all apart and compared parts from the spare carb i have. i havent put it all back together yet but i have cleaned everything properly after letting the whole thing soak in petrol overnight. some of the stains wouldnt come off without a good scrub. could anyone recomend something normally used to clean it all up? i doubt the mechs use petrol.. hmm?found this few faults.-the butterfly for the bigger barrel wont open coz there is a plastic cam connected to its rod that had already broken to piece. lucky the spare carbs cam is intact! pheww!!-i think the clay-ish material is from a small filter that is missing. it is supposed to be red in color in comparison with my parts carb. so i think it must have warped in the carburetor somehow? hmm...- this carburetor i took apart says pieburg on the side while the spare one says solex. i found that i couldnt interchange parts between these two as some wouldnt fit and some openings were sealed in the pieburg. are these two very differnt carburetors? would it be ok if i used the jets from the solex in this pieburg carbie?havent assembled the whole thing back together again as am busy now in melaka with work. will get the e21 out of its coma in the coming weekends hopefully. now am reading through some manuals to get a better understanding of the whole thing. for reference u can get it here..http://www.halsboe.dk/bmw/pics/solex/Solex4A1manualEnglish.ziptook a few pics and will upload them when am back in kl. any advice for a noob like me guys? :wink:thanks!!!

 

[Russie]

Good initiative there do keep us updated on the progress. Take your time and I believe you'd restore your E21.

Any E21 sifus here? Please assist our friend here.

Cheers

 

[beemer04]

I had the same problem on my solex, don't dare to open up as parts are not easily acessible, did spray the carb cleaner on the sticky parts, it works fine now, just could not resolve the rich mixture smell from the exhaust!

You should contact Rahman e21, pm me should you need his no?

 

[e21manic]

already took it to pieces but from what i see all the parts i require are in order.
hopefully i dont have a massive fault or else that would mean me saving up for a long time to get a set of twin DCOE webbers..

i have rahmans number.. yea think i shud give the sifu a call.. hehe

thanks for the info guys! will keep this thread updated as it happens..:top:

 

[e21manic]

heyya guys,
was doing some reading up on this carbie and on some forums they had not many good things to say about the 4A1. some even labeled it a lemon! :S vacum leaks are common and it warps easily. how true is this? how do i check the carb for warping? hope all is well with it!!
reading up also on the other problems it has.... hmmm
better come up with plan B in case i run into major issues!
what other carb set ups would be ok for the M20. am not looking for a powerful set up but a decent one that balances fuel economy and power as well..
-some go the weber route but its a bit tooo $$$ for me in terms of FC and getting it in the first place i feel.. but then again, any thoughts on the webers?
- was always fascinated by SU carbs. would a twin SU set up work well with a M20 engine? anyone seen this done before? possible issues?
-any other suggestions?
dont think i want to consider injection set ups coz.. i have this thing where i like to tinker around with my engine.. cant tinker muc with and injection can i?

thanks for the advice guys!!!!

 

[wjie20]

hey bro, (reviving an old thread here sorry). I've been doing some research on this Carb on google, and I found this thread. I think you posted on other forums as well? mercedes one. Anyway, I have the e12 and it's using the same carb, I suspect there is something wrong with the carb, I want to take it apart but I am unsure, could you give me some heads up on opening it up? I have never done this before. Thanks

 

[e21manic]

Hi bro,
glad to help out any way i can.
but before you plan to open it up, what exactly is the problem you are facing? best to see if it is something else before planning to open up this carb coz to get parts for it locally is almost impossible and with luck you could find it online from overseas sellers..
but what i can advice on this carb is that vacuum leaks and the choke is the common faults. as for the vacuum leaks, check all hoses connected to the cab and make sure it is all ok. as for the choke, there are two types. earlier models use a system by checking the water temperature so you would have a hose drawing water from the cooling system, and later models use electric choke. best way to differentiate is to see if you have any water hoses going to your carb. and also brand is it? Solex or Pierburg? these are two similar style carbs but some parts cant be interchanged.

my two cents is to bin the carb if it is giving you trouble. i threw my engine out and went the route of the motronic injection. the carb is great and sounds superb when high revving but it is also difficult to fix these days and it has a problem of warping, whereby the top half deforms and you can never get good vacuum no matter how many gaskets you use!!

but as i said earlier, for all you know it could just be a bad vacuum hose or something else so best troubleshoot other things before plannning to open the carb up..

all the best bro! hope your E21 runs again soon!

 

[wjie20]

Hmm, thanks for replying bro. The problem is starting. I tried starting it and when it finally started, it backfired. After that I couldn't start it anymore.

I was thinking that it's the choke. I also suspect the carb needs cleaning and retuned. But then again, I have no knowledge of this sort of stuff. I have a lot of interest in mechanical stuff.

I will try to find everything that needs to know. Btw, where to find the carburetor brands?

Thanks again!

 

[e21manic]

hie bro, the carb brand would be written on the sides of it. after you remove the air filter from the carburetor the you should be able to see it.
i not much of a sifu but lets help see if its actually the carb.

was the car running fine and this suddenly happened or was the car sitting and not started for a long time?

have you checked the ignition system? has it been dismantled before? is there spark coming from all the spark plugs? easy way to check is to remove them one by one, connect back the spark plug leads and when someone is cranking the engine, touch the end of the spark plug to the engine cover, you should see sparks coming from it. make sure no petrol leaks are anywhere.. lol.. if that is ok then ignition system should be good enough to start the car.

is fuel supply to the carb ok? there is a mechanical fuel pump mounted, if i am not mistaken, on the same side and area as the distributor. it looks like a mushroom with two hoses coming out if it and the top hose should be the one feeding the carb, you could check this by removing the hose that goes to the carb and crank the engine, fue should be gushing out.

if the top two are ok then the ignition and fuel system should be ok to start it.

where are you located btw bro? if not too far off i wouldnt mind having a look as well. im off this whole week to get my car done, why not help another E21.. :rock:

 

[wjie20]

Hey bro, thanks again for your reply. I will probably check on those when I have the time. The car is not completely mine. It's my uncles, but he is unavailable to do this now. I'm helping out as much as I can. For now I will get some info from the mechanic on your questions. I was told that the carb is kaput, but I suspect it's not that bad.

Btw bro, it's an E12 525 '81. Still willing to help me? Haha. It's currently at Bangsar area.

 

[e21manic]

haha.. i read wrongly and thought is was an E21.. but no worries if its using the same carb then the works should be pretty much the same as in the E21.. bangsar no probs, i am in ampang area and go to bangsar quite often. check with your mech and then see how we can proceed from there.

All the best bro!!

 

[wjie20]

Ok bro, how about you PM me your contact number? So we can arrange something. Friday should be free.