W114 Carbs\engine problem - Page 3 - Mercedes-Benz Forum

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post #21 of 93 (permalink) Old 04-24-2013, 07:46 PM
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I don't know that the stops missing is an issue, as the flap inside won't allow them to move beyond a certain point anyway. I suspect they are there to prevent any stress on the flap, since the weights are pretty substantial.

Where the function of the flap makes a difference is in cold start and warm ups. By heating the plenum the mixture is rapidly warmed, making the engine run better and allowing the enrichment circuits to close off more rapidly. It's an efficiency thing more than anything else.

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post #22 of 93 (permalink) Old 04-24-2013, 08:04 PM
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So then its really not necessary to fix if I am happy the way the engine is running?
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post #23 of 93 (permalink) Old 04-25-2013, 05:53 AM
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I fixed the flaps on a couple of my cars and didn't observe any difference in warm-up. My fintail has the same arrangement but with Solex carbs. A couple of years ago I had the manifolds off to fix a vacuum leak and I had the machine shop secure the flaps in the closed position. No issues with warm-up.

That would be my recommendation rather than trying to fix the opening/closing mechanism.

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post #24 of 93 (permalink) Old 04-25-2013, 06:01 AM Thread Starter
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Ok, I will not concentrate too much on the heat risers.
Can someone advise looking from the front of the car at the engine which one is in and out valve? I am also getting conflicting information on the gaps, what should the valve gaps be set to?
Thank you.


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post #25 of 93 (permalink) Old 04-25-2013, 08:08 AM
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Garage
You can tell which valve it is by matching up with the intake/exhaust runner.

Look at picture, round is intake, square is exhaust.

Exhaust: 0.008 inch

Intake: 0.004 inch



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Originally Posted by kavadarci View Post

Can someone advise looking from the front of the car at the engine which one is in and out valve? I am also getting conflicting information on the gaps, what should the valve gaps be set to?
Thank you.
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post #26 of 93 (permalink) Old 04-25-2013, 06:32 PM
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when you have warped top housing on the cabs , the fix we used to do , is putting them on a flat surface , and hitting at center with hammer , this would work everytime . the flat surface could just be a clean concrete floor .
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post #27 of 93 (permalink) Old 04-25-2013, 07:49 PM Thread Starter
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ok,
i need to understand which position is open and closed for the heat risers.
looking from the front of the car at the engine the first flap is stuck into upper/right position and the second i can push lower/left position where the lower stoppers are.

Can i visually tell that i have warped carb plate without removing anything?

and third, :-) how do i turn the engine manually, i have the car in neutral and all the plugs out and via the belts this thing is not moving at all.

Thank you.
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post #28 of 93 (permalink) Old 04-26-2013, 02:44 PM
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I personall have not had to adjust my valves as of yet, but this is per a repair manual.

The valve clearances should always be checked when the engine is cold. Try turning the crankshaft by means of the pulley bolt until the long profile of the camshaft lobe nearest the front of the engine is pointing upward (cam base circle of camshaft next to rocker arm) Now insert a feeler blade between the cam lobe and the rocker arm to the specifications. The feeler blade should be a stiff sliding fit. If it is not, adjust the clearance by turning the ball pin. The ball pin has stiff threads and is self-locking. Where it is found that moving the ball pin still does not provide enough clearance between the camshaft lobe and the rocker arm then an alternative thickness thrust piece should be obtained and fitted. These thrust pieces are available in several different thicknesses. When the first (exhaust) valve has been checked, continue with the next valve and so on. If the firing order of the engine is followed (1-5-3-6-2-4) it will avoid excessive rotation of the crankshaft. Remember that the inlet and exhaust valve clearances are different so identify the valve carefully before checking its clearance. Refit the spark plugs and rocker cover.
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post #29 of 93 (permalink) Old 04-26-2013, 02:45 PM
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As per my heat risers. I'm not too sure either. I will try to get in there and figure it out,
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post #30 of 93 (permalink) Old 04-28-2013, 04:05 PM Thread Starter
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here is an update:
i have measured the compression on each cylinder and here are the numbers:
1. 100psi
5. 100psi
3. 120psi
6. 130psi
2. 120psi
4. 100psi

are these numbers normal?
what is the expected compression for this engine?

thank you.
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