HELP Still no luck understanding where to connect vacuum hoses after converting carbs - Mercedes-Benz Forum

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post #1 of 1 (permalink) Old 04-08-2016, 08:39 AM Thread Starter
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Date registered: Sep 2013
Vehicle: 1963 230SL & 1972 280C (sold sadly) & 1973 280C
Location: Portland, OR
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HELP Still no luck understanding where to connect vacuum hoses after converting carbs

Hi Guys. Weekend coming up. I'm going to get time to play on my M110 / 280C now with Weber on it.

My issue is this:
+ the Solex had 4 vac hoses connected to it! Weber has only 2 nipples.
+ that leaves me with 2 free/disconnected hoses. I can cap them off back at the pots they originate from (near the left wheel well) okay, but then i have another unspoken for vacuum nipple:

+ On the fuel line going into the carb there is a kind of 3 way valve thingee... It's the fuel pressure regulator / FUEL RETURN VALVE. and on (mine anyway), there is a vac nipple on the bottom, and this is one of the lines that *was* connected to the SOLEX, BUT NOW HAS NO HOME.


Do I...

a) cap it off on the fuel pressure / return valve and use it as is?
b) connect it to one of the now-free vac hoses that no longer needs to be connected to the carb (since the webber only needs 2 and the Solex needs 4)
c) remove the fuel pressure reg/return and get another model (part number?) that does not require a vac actuator of any kind.

(if c, i need a part number. the blue workshop manual shows a part just like it without a vac hose on it, but no number, and mentions that this is the new (in 1975) style replacing the old style (eg. mine) and doesn't need vac)

Help! Please and Thank you.
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