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What causes spark plugs to foul up with black
soot. I just changed them a couple of months ago
53 chevy ...235 engine..

Burning oil, a slightly hotter plug could fix it if they are fouling.

To much fuel can also do it. Hows your fuel milage? The hotter plug is a good idea. You may not be running or working the engine enough to keep them clean. A hotter heat range will help burn the carbon off. Put a load on the engine every now and then to keep the cob webs out

Joe

How well does it SOUND like it runs?
The other two guys Tony M and Joe H, are or may both be correct.
Check your plug heat range an see if it is the correct plug for the truck.CHeck your points ,set them and then set the timing as well.
,
Is your truck still 6-volt?
Have you read Kens post on how he set his points in the dark?
May help.

.
Let us know

Yep it's still 6 volt 235 motor...Just went out
and pulled a plug to see whats in it...AC R45
and it's all blacken with soot again...
I set the points at .019
It starts good and the engine sounds good, but
every once in a while, when it starts black soot come out of the tail pipe..???

If it is wet black , then that would be excess oil .
If it is dry black then it may be excess fuel . Check the idle mixture setting .
Check the float level . Check the needle and seat are ok.

My 250 would do the same thing, blow black watery crap out the pipe and all over everything. I keep leaning it out till it started to run rough. Then I stepped it back up till it smoothed out. The black crap went away. I never did look at the plugs, I new what they would look like. By raiseing and lowering the float, you can make a drastic change in how it runs. The Idle screw also changes how it runs. The idle curcuit is always working even with the carb open. If idle is to lean or rich, it affects the rest of the carburator and how it runs over all.

How does the exhaust smell, fuel or oil burning. You can control the fuel part. If oil burning, you can live with it or put money into a rebuild. The hotter heat range will keep it on the road for a while. Try one or two ranges hotter. If this a parade type non working truck, you won't have any problems. Joe

The motor is not burning oil, but the
exhaust does smell strong when starting. My
next questions are: 1. Raising or lowering the
float what happens when this is done.
I'm gonna try hotter plugs also and check the
idle screw to-day...thanks everyone..

It sounds to me like the power valve is not working like it should. When you remove the top of the carb, check to see if the plunger that opens the power valve is free in it's bore and the retainer is installed correct, also make sure the gasket between the bowl and top is correct and letting vacuum pull the plunger away from the power valve when high vacuum is in the intake manifold. I would look at the power valve to make sure it is in good shape and will close when the plunger is pulled up by vacuum.
Good luck!

the ac-r35 plug is a resistor type plug...isn't that generally used in an HEI system???. couldnt you go to a non-resistor type plug

Its the carb & weak spark. My 235 used to do this all the time when I had the 6volt and rot-pot carb. Set the points for about .017 or .018. Your plug heat range is fine. Check the power piston to make sure its moving freely in the carb. Also check for a loose main jet, high float level or plugged air filter.

chip

The float level can make a big difference when trying to tune a engine. There is a tube or fuel passage in the carb that sticks down in the fuel bowl. When fuel is needed buy the engine, vacumn pulls on the tube to draw fuel out. There are air bleeds in the top somewhere to let air in with the fuel. With out the air bleeds, it would draw way to much fuel. By raising or lowering the fuel level, more or less fuel in drawn in. Its just like drinking out of a straw, with the cup full its easyer to get a mouth full.

The distributor will fire any plug at the end of a good wire. The resistor is there to cut out electrical noise in radios. They won't hurt a thing. It will cost you a set of plugs if they don't work out. Its part of tuning. You never know what will help if you don't try it. Joe

Is it possible to purchase some kind of guage to
set the level of the float in a carburator. Or at
least determine if it is sitting right.

A simple machinest ruler will work, or any ruler that will read in 32's. Some will come up with the correct measurement. Carburator rebuilt kits have the gauge and specification. Joe

Thanks Joe ...hope someone will come up with a
measurement for me. Here's the question again.

Can someone give a measurement to set a float on a 53 chevy 235.. When I rebuilt the carb I
threw away the "T" guage to set float...I know
deh!

Yep;I found the answer "Truckernix" posted
in the upper threads...thanks