What is the correct Choke richness setting? - Mercedes-Benz Forum

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post #1 of 5 (permalink) Old 09-20-2013, 09:52 AM Thread Starter
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What is the correct Choke richness setting?

I read about this a while back, but I cannot seem to find the info anywhere. What is the correct setting on the choke "starter cover"? As you can see in the photo, the cover mark is set at the yellow arrow, should it be there or rotated to the line where the cyan arrow is pointing? The manual on the jaimekop site ( http://www.jaimekop.com/CarbManual/Page18-19/index.html ) shows that it needs adjusting, but it is not very specific to where it should be adjusted to.

Thanks guys!
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Last edited by Luna Gaudi's 72 250; 09-20-2013 at 09:56 AM.
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post #2 of 5 (permalink) Old 09-20-2013, 05:12 PM
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The manual says the rear one should be a bit rich when the car is new and then they should both be at the center line after the first service

since that was 40+ years ago they should be at the center line..

I have noticed that in some cars, the bi-metallic strips inside are old and binding and the choke doesn't pull off correctly unless the covers are adjusted a bit to the lean side, so I would use trial and error to find what works for you. there are other adjustments on the Zenith chokes, the top screw is a trim for example

good luck !
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post #3 of 5 (permalink) Old 09-20-2013, 05:35 PM
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The center line is a reference point and nothing more.

Depending on the climate you live in, you may need to adjust these seasonally. The mark is just a place to start from and not a whole lot else.

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post #4 of 5 (permalink) Old 09-20-2013, 10:07 PM
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the closed air gap has to 2.2 mm for perfect starts.

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post #5 of 5 (permalink) Old 10-06-2013, 04:53 AM
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Hi choke covers were set at datum mark at factory,when vehicle came for first service had to be retartded by 5 mm (earlier opening) change in emission rules Germany and Australia where I am. Choke covers for these engines and M130 had different Bi-Metal springs,23 for front & 18 for rear if memory is correct. Rear choke activated via 60 degree thermo switch, front via terminal 15 (IGN), front opened earlier & has fast idle adjustment, rear no adjustment. Pre Throttle Gaps should be 2.4 mm when engine has started and running, (220 SB with ZENITH 2.6mm).
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