Has anyone done this before....standard carburettor to Webber system

[ESO]

Dear all,

My 1977 280S (W116) engine keep cutting out at idle during traffic jam and I have just been told it is likely to be caused by the stanard carburettor system in the car. Someone suggest that I should replace this standard unit with a WEBBER 38DGAS with a conversion kit ::: http://69.0.202.131/html/kits/k248.htm .


Now, I would like to ask if anyone here has done this before and how much better apart from solving the engine problem will this new system do? If I should have it replaced, does anyone know where is the best place to get this and how much in total will I be looking at? I am struggling whether I should keep the car and really am a bit lost as I do not want to drive a car that doesn't give me confident driving on the road.....Please help if possible.

Thank you

ESO

[oscar]

Hi ESO,

I've been researching a similar subject ie Carburettor replacement/servicing.  Not sure about the Webber specifically, but why not.  I have had running problems in my recently acquired 280S, one of the culprits is the carb.  But I have a Holley carb model 4160 list#8007.  I was a bit disappointed that the original Solex 4 A 1 wasn't in the car but have now reversed my thoughts on this as some other forum searches tend to give the Solex unit a bad rap.  Partly because of the non existence of Solex anymore and the more complex functions built in which other carbs can do without so much fuss.  The others keep it simple.  There's also the layout and difference in size of the barrels within the solex that differ from 4 same sized in the primary and secondary barrels.  My opinion has swayed that far from the solex that two 4 A 1's sold for $25AUD yesterday on ebay without me bidding.  I'd rather tackle the Holley.

A Weber or Holley I think will be much easier and cheaper to service than a solex but that's my opinion without experience.  However, a rebuild kit for the Holley is $75AUD from Melb in ebay, including jets, gaskets, diaphragm etc.  In the new year I'll be rebuilding mine.  Never done it before, but the online support for this carby is great.  I'll be coming back with a full report on how rebuilding this carb changed the way the car runs.

There's a few options before you consider replacement.

1  Download the PDF's from the Library about the Solex.  There's a few reasons why your Solex could be starving the engine at idle, or flooding it perhaps.  You should consider servicing it yourself first to see what the problem is. It could be simple like an idle/mixture screw.

2  Read these BMW related sites-
    Solex rebuild
    carb replacement

A replacement is an attractive option.  There are other brands too.  Your only issues will be first up tuning and adapting the carb to fit the manifold.  After that you will know the componentry of the carb is new.

My running problems are here.  A few issues, but I'm really looking forward to see what a carb rebuild will do. 

[ESO]

Hi Oscar,

It's great to hear from you, specially on this issue. Since I do not have time and the correct tools, I sent the car to my mechanic friend nearby and I have yet to find out what he had done but during my visit last night, the car seems to idle a lot better or I should say idle well without cutting off. However, I have also noticed that whenever I step on the brake hard, the idle speed seem not very stable. This will be further investigated today. My friend said he guarantee it will runs well.

Anyway, this still doesn't stop me from considering having the Webber system as a replacement. According to the websites I have study, the 2-barrel Webber system allow a better response, improve in fuel economy, less maintenance, etc. advantages and from one of the US site, they are selling a kit for USD670 + shipping which is quite reasonable. Let me do a bit more research and share the info here, please keep in touch.....

Merry X'mas

ERIC

[oscar]

That bit about stepping on the brake, same thing here.  If I kept pumping the brake I could get it to stall.  It's all vacuum related and I had various vacuum leaks or disconnected hoses.  Once I reconnected hoses and replaced missing ones things improved but my idle will still drop with braking like that.  There's so many things that affect idle, igniton timing, leads blah blah. There's a few. 

If you have this friend that will do the work then think about a replacement.  But see if your solex is still serviceable first. I've still yet to look up what weber has to offer and compare it to the holley and solex.  I thought the price you quoted was a bit steep only because i "thought" I saw a Holley new for around $400USD.  Unlike some other components of w116 engines that "need" oem stuff, in my opinion, a suitable carby replacement in the 280S application is an exception where once tuned a new replacement should have it running well. 

Yes please keep us informed It would be good to read more about Mercedes experiences then BMW fixes I'd love to post more on the Holley rebuild but I dare say you'll get yours sorted out before I do mine.

Merry Xmas

BTW, Does HK celebrate Xmas now that it's Chinese rule?  Do you get the Chinese New Year off as well?  Best of both worlds 

[ESO]

Dear Oscar,

Thx again for your advise. I also saw this ignition system which seems would be good for W116 ::: http://www.vintageperformance.com/retrorockets/PerTronixConversions.htm . The price seems reasonable (approx. USD100) which should improve a lot for the car. I remember when I was still in Melbourne, I installed a similar system for my 1979 Range Rover and I could feel the difference. The only thing you have to give them is the ref. numbers on the distributor. Most likely they have a kit instock.

Here, we do celebrate X'mas of course, it is a big date for most people and yes, we do get from time to time some holiday from now until Feb.

Best regards
ERIC