Solex Carb Adjustment

[Tom Oxner]

My son and I are still in the process of bringing the 67 912 back to life. I rebuilt the carbs and put them back on the engine. The engine runs good as long as you are accelerating. To get the car to idle I have to back the idle adjustment screws out about 4-5 turns (a gret deal more than the suggested 1.5 turns). Any less and it is very lean (popping back thru the carbs). These are split shaft carbs. Any suggestions (other than purchase webers)? Thanks,

Tom

[maybe368]

Make sure that the float level is adjusted properly. You said that you are turning the idle adjust screw, but it sounds more like the air-fuel mixture screws (x4). It certainly sounds like a lean condition. If it is all 4 mixture screws that do that more or less equally, it seems like a general fuel delivery problem like low fuel pressure from a bad or kinked fuel line or bad fuel pump. It would be unlikely a coincidence that all 4 carbs have blocked jets or a similar common problem, although with some of the gremblins that seem to dwell within these cars all bets are off, Good luck Mark

[Tom Oxner]

Thanks for your suggestions, Mark. You are correct, I am turning the idle mixture screws. I set the float levels as the manual suggests (fuel slightly running out the sight hole plug removed) and it seemed to make little difference. The engine pulls to redline in third and seems to run strong (based upon how I remember my old 356B running). I rebuilt the fuel pump and it has good pressure as well as volume. Thanks for your help, I will keep tinkering.

Tom the Tinkering Man

[j.hall]

Tom, I too rebuilt my solex split shaft carbs but found that if the bushings are worn (that support the shafts) nothing I did would make the car run correct. If you can see a worn slot where the butterfly has rubbed in the throat its a good indication.
I sent mine to Beiker Engineering and had them re-manufactured. I'm by no means an expert on these carbs but followed his mounting and set up instructions and was quite pleased the results. The cost was actually a little less than replacement Weber's.
Its a time consuming process though...but Beiker was upfront about this. Fortunately I sent mine out during the winter and was ready to roll by spring.
Best of luck!
Joe

[C. Clark]

If indeed the bushing are worn they must be redone, look to the 912 Registry for links and threads on this very popular topic. Personally I employed Harry Bieker to rebuild my Solex 40s with very positive results, to say rebuild is a insult though, more like re-manufactured. You must know though that Bieker comes with mixed reviews, John Benton is another carburetor expert associated with the 912 community, I have no personal experience with him. As previously mentioned much information is available at http://www.912bbs.org/index.php
Best of luck,
Chas.
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