Black soot ok plugs

[elvaliant66]

Hey slant nation I got some concerns on my slant and wanted to see if u guys have any input or can lead me in the right direction. I have.' 66 170 with a Holley 1920 .its an original carb I have rebuilt it about 3 months ago and set the float to the best of my knowledge which is half way to the body of the carb. The kit never came with the gauge stick to do any accurate setting. It ran fine after that till about 3 or 4 days ago. It started idling low and leaving a black spot on my driveway from the tail pipe . It has never done this before ..I adjusted the carb to the best I can.I'm assuming it might be the carb again , making it run rich but I just checked my plugs and they look fine .theyre not white or black they're a light tan color. I also discovered a little black splurge on the surroundings of the intake runners in the manifold . Is that another sign of running rich? Or is it just some loose intake nuts that I have to tighten which I already snugged up a bit.ive been thinking of going super six but now I wanna wait and fix this problem before I do some light mods.i also have adjusted my valves to .11and .21 and I have the electronic ignition to mining is at about 10btc. Sorry for the essay but I need some fellow slant sixers help. Thanks in advance guys

 

[elvaliant66]

Anyone?

 

[nm9stheham]

Are the temperatures getting colder there? (Sorry, I don't know where 'sgv' is...) It may just be the choke working in the cold temps.

By the way, look up 'wet float setting' for your 1920 carb. That is the most accruate way to check the float setting. But your spark plug color sounds good.

 

[Double M]

Are the temperatures getting colder there? (Sorry, I don't know where 'sgv' is...) It may just be the choke working in the cold temps.

By the way, look up 'wet float setting' for your 1920 carb. That is the most accruate way to check the float setting. But your spark plug color sounds good.

I'm guessing 'sgv' is San Gabriel Valley (AKA Los Angeles, CA).

Russ.

 

[AJ/FormS]

My slanty is a 225. It does not like 11/21. It runs much better at 13/23.
yBlack soot inside the tailpipe is not good.Tan plugs is vert good.These two do not usually appear together.
The slow idle seems to indicate a mixture problem; but could be a slipped timing issue. If there are no other driveability issues, such as powerloss, stumbling,etc ,this is what I would do.
Fill up with fresh gas, recheck the timings, make sure the choke is coming off in a reasonably short time, make sure the choke pull-off is working and that the vacuum break is correctly set, and check for vacuum leaks. Then roadtest.
If you still have problems, I would increase the valve lash to .013/.023.
Oh yeah, check to be sure the float-bowl vent is open.
If you still have problems, revisit the fuel level.

 

[elvaliant66]

Are the temperatures getting colder there? (Sorry, I don't know where 'sgv' is...) It may just be the choke working in the cold temps.

By the way, look up 'wet float setting' for your 1920 carb. That is the most accruate way to check the float setting. But your spark plug color sounds good.

Yea it's San Gabriel valley basically low Angeles. The coldest is getting here is about 43F . I actually don't have the choke hooked up I have to adjust it and compensate for the 1 inch difference . I have a 170 in a 72 valiant. Never had a 170 choke the one I have now was for the 225. I just gotta snip about an inch off the rod of the choke that connects in the carb . Hopefully that works. I'll look at the wet float setting again and tinker with it

 

[AJ/FormS]

If the choke is not hooked up, then to keep it running during the warm up period, you will have to either babysit it (lots of pedal pumping or a higher foot-controlled idle), or you will have to compensate it with rich mixture settings and or a higher float level setting, and/or additional timings. Any of these fuel band-aids can/will cause the soot in the pipe.The tighter valve lash may also cause issues, but not usually until the engine is fully warmed up. The loss of fast-idle will also drop out the vacuum advance, and the engine really needs that at this time, to promote a full burn of the fuel. Without it, the engine is running ,comparatively speaking, retarded, so not all of the fuel will get burned.
Also keep in mind that icing can occur at temps just a little lower than 43*F

 

[nm9stheham]

OK....and sgv... now I know! I mention the soot with warming up because my '62 does the same thing regularly, but the plugs look A-OK. Float is right on the mark, using wet float.

While the carb is idling and warmed up, look down the carb throat and make sure there are not any drops of gas dripping down the throat. And check the same when you shut the car off; the carb throat should remain dry, and not be seeping any gas.