1971 220 - Page 12 - PeachParts Mercedes-Benz Forum

#**166** 12-24-2005, 03:44 PM

Quote:

Originally Posted by meltedpanda

when I asked the parts guy about a hotter plug he could not give me any advice, what "number / type" should I ask for?
I am also going to try to lean the carb mixture per Marks suggestion

Not long before your car was built, Mercedes used to recommend a cold plug for highway use, and a hotter plug for city driving. They also used to have a summer and a winter thermostat.

What you want is a plug that is ONE heat range hotter than what you are using now. Depending on plug manufacture, the number on the plug will be either higher or lower. Champion used to be one way and now go the other way, I forget which way.

If the parts store you use has a actual paper catalog for the brand of olug you want, it should be easy to figure out. Believe it or not, another great plug to use with older sensitive motors is the NGK brand. Make sure you get NON-RESISTOR plugs.

If you have a NAPA in your area, they should be able to help you.

Those stromberg 175CD carbs are a real pain. If you can find a early model 220/8 with the dual Solex carbs, your life will be much easier. You need to switch over the intake manifold also. Considering you were able to rebuild the fuel guage sending unit, that should be a problem.

You might also want to check the resistance in ohms for the plug wire on the cylinder that is fouling out. The ends of the plug wires can fail and cause the plug to foul. Good luck.

meltedpanda · #**167** 12-24-2005, 06:16 PM

Thanks
Today was a good day despite the fact I had to work this morning

When I looked at the lean rich mechanism I found that the lock nut was undone and the entire mechanism had worked its way to the rich side. I suspect because of engine vibration. I leaned her up and I was able to zoom about and actualy got her up to 60! responded pretty well. It was way way out. This may solve my plug problem...
Now the question is how lean to make it and how do you tell????

I also seem to have oil squirting out down by where the dip stick runs into the engine or somewhere around the housing, can't tell yet. I thought it was PS fluid but it is not. Any thoughts on where these are prone to spit oil under load - R side.??

meltedpanda · #**168** 12-26-2005, 11:21 AM

Is the best way to tell lean rich adjustment by looking at the plugs?
I looked for information on settings but could not find anything

250 Coupe · #**169** 12-26-2005, 07:36 PM

I found this cool page with color pictures and everything.

If you are into gadgets, you can look for a colortune and set the mixture by looking at the flame color.

I have the Digital Gastester from back when it didn't cost quite so much.

Michael

meltedpanda · #**170** 12-26-2005, 10:03 PM

excellent 250, thanks. I noticed today that they are getting a brownish color to them, I am moving in the right direction!!
Can plugs once fouled as mine have been be cleaned or should I start anew now that I am approaching proper air fuel mixture?

250 Coupe · #**171** 12-27-2005, 11:55 AM

I'd start with new plugs. When I've tried to clean plugs in the past, they don't really come back to white.

Michael

meltedpanda · #**172** 12-27-2005, 06:23 PM

thanks
Found the oil leak, it seems to be blowing out of the top of the oil dipstick, it does not fit tightly, may be mssing a rubber gasket at the top???
I was able to salvage a muffler and mounting brackets off the donor today so I now have a muffler. Drove 14 miles today around back country roads and she felt good. I need some tires as these are pretty dry rotted and out of round. Engine is running good, good pick up, minimal smoke.
Next stop will be body man, in the meantime cleaning up interior pieces, taking carpets to get steam cleaned.
As always....more to follow

250 Coupe · #**173** 12-27-2005, 09:02 PM

I don't think it should be blowing oil out the dipstick, even if the rubber stopper is toast. On my M130, the crankcase breather hose goes into the top of the air cleaner and then to a flame trap. There is a calibrated vacuum leak at the bottom of the flame trap to draw crankcase vapors into the intake. Sort of like a PCV setup but without the valve.
Might yours have something similar that could be plugged up with gunk? That would allow the crankcase to become over pressured and pop the dipstick.

Lemme check the CD and get back to you later.

Michael

250 Coupe · #**174** 12-27-2005, 10:06 PM

After checking the CD, there's way lots of info on the Strombergs. MB made a lot of running changes to the carbs, different mounting, backfire protection for the diaphragm, idle solenoids and so on.
If you don't have one, you may want to get one.
The hose from the crankcase to the air cleaner may have a flame trap inside that could be gunked up to the point that pressure is building up enough to pop the dipstick.
The "controlled vacuum leak" draws vapors at low speeds but at road speeds, there isn't enough vacuum so the vapors go around the water separator and into the air filter itself.

Michael

meltedpanda · #**175** 12-28-2005, 09:55 AM

The hose from the crankcase to the air cleaner may have a flame trap inside that could be gunked up to the point that pressure is building up enough to pop the dipstick.

Where do I look for this hose, flame trap?, I don't see any hose going to the air filter. This is a 4 banger. there is what appears to be a nipple of sorts off the center of the last rubber piece that attaches to the carb. This has a bolt in it probably from PO. No hose attached I have no clue as to what that was for.
Also new question for the day to ponder. I love having a few days off

I have replaced all the brake hoses, some new metal lines, new rear rotors, flushed system, bled system. Brakes now work great, stop smoothly, however the brake light on the dash stays on. I do not have my brake lights attached to the body, nor any other bulb housings. Can this be the reason? I know in the newer Benz, if a brake bulb goes out the red dash light comes on. Did this technology exist in 71?
The fuses look good
Thanks.

Mark DiSilvestro · #**176** 12-28-2005, 11:43 AM

Brake warning light could be the switch on the parking brake or the fluid level switch on the brake fluid reservoir.

Happy Motoring, Mark

meltedpanda · #**177** 12-28-2005, 02:03 PM

Hey Mark, Welcome back, I will check, I assume by your answer that bulbs out/disconnected would not cause the light ot stay on?
Where is th switch on the brake canister.
Also your thoughts on this oil blowby?, or blowout?
reading some posts it looks like a got a crankcase pressure problem, question is where does it vent? to and from, I see nothing
If you look here you can see the nipple between the carb and the air filter that has a plug in it (black nipple in th emiddle right before carb)
http://www.villagephotos.com/viewpubimage.asp?id_=15034064&selected=

250 Coupe · #**178** 12-28-2005, 06:19 PM

Ok, I see what you mean. The big curved hose from valve cover to intake isn't correct.
The factory hose is formed at a 90 and the short end plugs into the vavle cover. The long end connects to the water separator you don't have

The lower end of the separator connects to the intake where the current hose is attached. This point is the "controlled vacuum leak". It's a small orifice and is easily overpowered by the crankcase at speed. To compensate for this, there should be a second hose from the water separator to the plugged pipe in front of the carb.
I think that is why you are pushing oil out the dipstick tube.

I'm posting a PDF that, if it works, should help.

Michael

250 Coupe · #**179** 12-28-2005, 06:23 PM

My brake warning light switch is centered between the two filler caps on the master cylinder. The parking brake uses the same light and the wire for mine was trashed. All it needs to do is touch ground and the light will come on.

Michael

The PDF worked

Mark DiSilvestro · #**180** 12-28-2005, 06:52 PM

Your PCV system should have the hose from the valve cover connected to a ping-pong ball sized, black plastic or rubber vapor separator at the intake manifold. The separator should have a second breather pipe connected to a nipple on the side of a rubber boot connecting the throat of your carb to the air cleaner duct. That second pipe is supposed to bleed off any excess crankcase pressure, that the PCV port on the intake manifold can't handle. The original rubber boot and vapor separator appear to be missing in your photo. The hose from your valve cover should not be connected directly to the intake manifold without that vapor separator and breather pipe.

No 'bulb-out' warning circuits on these cars.
There should be a switch, or pair of switches on top of the master cylinder reservoir, that will turn on the brake warning light if the brake fluid is low (or the float or switch is messed up)

Happy Motoring, Mark