still fighting extreme rich condition

markyb

markyb

Senior Member
Been fighting this all summer, even broke down on the way to Greenfield Village and had to be towed...


Yesterday I swapped modern points setup back to original design, thinking that I had intermittent shorting. My carb was sent back to Renner's to make sure everything was in order after his rebuild, checked out OK. I started the car, and again, looked like a giant black smoke machine at the exhaust. Even though Renner double checked the float, is it possible that it is hanging up somehow? I've never had the carb apart and would like to check it as it sits on the manifold. turning the idle screw fully closed or opening all the way has no effect on running at low idle, probable due to so much gas flooding in.

I have the Wix filter setup suggested by Mitch to ensure no debris enters the carb
 
For trouble shooting purposes, remove the air filter and see if the problem still exists. With the air filter off see if any gas drips out when the engine is off but the fuel is on, you may have a leaky float valve, a common problem with stock carb rebuild kits. Also how is your GAV set? It should be about 1/2 to 1 turn open to start. And yes during shipping things could happen to the Carb, make sure the float pin is centered and the float does not drag on the bowl. When you tip the carb you should not hear the float rubbing on the bowl, the pin is just loose so it can move around with rough handling in the mail.
 
do you have good fuel in the tank
do you have a strong blue spark at coil wire
i also like to check things with spark testers for intensity and rhythm which would show up problems in the igniton circuit while running
many things can cause rich mixture or fuel from burning properly
how is the cond of the loweer dist plate wire
usually a dumping carb would be flooding on the ground
 
Fresh fuel, no air filter, GAV open a quarter turn to start, then shut off completely after a minute. Electrical stuff has been gone over with a vengeance! Used an ohm meter as I installed the new original points setup, everything checks out, .020" point gap, timing is TDC with the spark lever in full retard position. The re-check by Renner of the float needle showed no problems, and he added a Viton seat for good measure.
The engine has about 150 miles since a full rebuild from AER, 6.0 head. Exhaust/Intake gaskets lightly sealed with hi temp sealant, leaks unlikely as I have been very careful to eliminate any of these issues.

Not being familiar with the carb, can I drop the lower half as it sits on the car and see if the float is hanging up somehow?

I'm being a bit lazy by asking, will dig out my manual right now, not sure if it has an exploded view of the carb....
 
Mitch//pa said:
do you have good fuel in the tank
do you have a strong blue spark at coil wire
i also like to check things with spark testers for intensity and rhythm which would show up problems in the igniton circuit while running
many things can cause rich mixture or fuel from burning properly
how is the cond of the loweer dist plate wire
usually a dumping carb would be flooding on the ground
Click to expand...


Mitch,
I have one of the NuRex cutaway distributor caps on it right now, spark looks strong at all 4 contacts in the distributor. The coil, points, condenser distributor cap are all new....I keep coming back to too much fuel being fed to the engine, plugs foul up within 5 minutes of running!

I'm going to hunt down another carb, good to have a backup, surely someone here in town has one, I'm going to my monthly East Side A's mtg on Tuesday, will see if someone can bring one...
 
markyb said:
Mitch,
I have one of the NuRex cutaway distributor caps on it right now, spark looks strong at all 4 contacts in the distributor. The coil, points, condenser distributor cap are all new....I keep coming back to too much fuel being fed to the engine, plugs foul up within 5 minutes of running!

I'm going to hunt down another carb, good to have a backup, surely someone here in town has one, I'm going to my monthly East Side A's mtg on Tuesday, will see if someone can bring one...
Click to expand...

ok keep us posted...renners is pretty good so i am figuring your carb is good esp since you sent it back for a recheck
also make sure your oil is not fuel saturated.
we do some auction cars at work with many having contaminated fuel. we get a sample pour some on the concrete and light it to make sure it has a strong and complete burn.
 
Is it best to set the bowl level with the carb mounted to the car with a sight glass gauge?
 
I wondered the same. I had lots of problems with flooding and sooty spark plugs when I used Motorcraft TT10 plugs. Champion W 16 Y wasn't much better. I now run Champion W 18 and they run clean and perform really good.
 
What plugs are you running?? What gap?? Were they new after engine rebuilt ??

"turning the idle screw fully closed or opening all the way has no effect on running at idle" This is probably directly related to your problem. Ck for a vacuum leak at the carb and/or intake manifold. JMO
Paul in CT
 
Purdy Swoft said:
I wondered the same. I had lots of problems with flooding and sooty spark plugs when I used Motorcraft TT10 plugs. Champion W 16 Y wasn't much better. I now run Champion W 18 and they run clean and perform really good.
Click to expand...

hmmmmm, those are exactly to two that I've been running, gapped at .035", swapped back and forth as I've cleaned them during my quest for finding the problem. The w18 runs a bit hotter?

With clean plugs, I'm still blowing black, sooty exhaust at cold startup and it never goes away after the engine is warm...I'll try that plug, thanks
 
Another thought is if the idle adjust screw at the throttle of the carb is adjusted to fast, the idle circuit in the carburetor can't cut in. if its not running on the idle circuit , the air adjust screw on top of the carb will have no effect.and yes the W18 is a hotter spark plug
 
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Just a thought, but nobody has mentioned burning oil, oil might be getting past the rings and burning when the cylinder ignites. After it warms up it might not be as bad because the rings get hot and expand, not letting as much oil pass by.
 
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