Eyes Tearing on fumes

My small block stroker seems to run fine, but do I have to jet up or down to cut down the fumes when idling, I cant stand the tears when its just sitting at idle.. Is it running to rich or lean?? It is a Pro-Form main body with 4 corner Idle..I do not remember the jets size right now, but can check

Rich, or poor electrical, eyes tear from un burnt fuel.

So do I cut down on the jet size?? I think my electrical is in pretty good shape..
thank you

jets are not being used at idle, try adjusting the two or four idle adj screws on the side of the carb for the highest vacuum.

Then Im screwed, since I have the 4 corner idle setup for the best vacuum around 12#..maybe I can tweek it in some more..
thank you

What is your vacuum at idle and what PV (#) is in there.

I am pulling around 11-12#..I do remember that the PV was set for around 12#..Is the PV open during idle??

it would appear so. W12 in hg @idle might go with Holleys recommendation of half that which'd be 6 (for starters) more on that later. I'm not sure if this is a valid test on a 4 corner idle setup but turn all 4 idle mixture screws in until they are lightly seated & count # of turns if need be to easily return them to where they were when you are done) and see if it dies. If it'll still idle it's a dead giveaway the the PV is open @ idle and it should not be open then. Float levels have already been checked right?

Float levels are perfect..and I do remember the PV is set for 6..I will run your test to see if its open during idle..thank for the help

Check for a vacuum leaks around the intake manifold. Mine did the same thing and found that I had a really bad vac leak there.
attaboy

Alright the carb appears good. What is your initial timing at? Next I'd bump it up then close down the throttle/adj mixture screws. this'll over advance the total but for now keeping it at idle & see if this makes a (positive) difference in the idle quality and the fumes

My initial timing is around 18 and total around 34..I will try and dial down the mixture screws, hopefully it will kill some of the fumes..it really brings tears to your eyes when its at idle..
thanks for the help

Taken from someone else's post:

"Contrary to popular belief, the mixture needle does not control the idle circuit air/fuel ratio. Although this may simply be a matter of semantics, there is a difference between the mixture in the idle circuit itself and the mixture that ultimately reaches the intake manifold. The idle circuit calibration is determined by the diameters of the idle feed restriction and the idle air bleed. A 'feed restriction' is nothing moere than a metering jet for the idle system and the air bleed serves as an airflow regulating orifice. As the air/fuel emulsion exits the idle port it is mixed with small amounts of intake air that flows past the throttle plates. Varying the throttle plate opening (with the idle speed screw) increases or decreases both the amount of air that is allowed to flow into the intake manifold and the amount of pre-mixed air/fuel emulsion discharged at the idle port. Since these two idle mixture components are affected by degree of throttle opening, the ratio of intake air to idle mixture air/fuel is not drastically altered by changes in idle speed. Turning the idle mixture screw varies the volume of air/fuel emulsion discharged into the manifold, not the ratio of air to fuel in the emulsion. Therefore when a satisfactory idle cannot be achieved by tweaking the mixture screws richer (more idle air/fuel to intake air) or leaner (less), it can be assumed that the carburetor idle calibration is not within the range demanded by that particular engine.

The use of two four-barrel carburetors is an excellent example of such incompatability. With such an installation, the volume of air/fuel emulsion is effectively double that available from a single four-barrel mounted on the same engine. Even when the mixture screws are adjusted toward lean, there may simply be too much emulsified idle fuel flowing to allow a clean idle. In such cases the idle feed restrictions of both carburetors must be reduced, in cross section size,to lean the idle mixture to an acceptable level. These types of alterations are confined almost exclusively to highly specialized race applications. Satisfactory idle performance can, for the most part, be achieved by varying the settings of the idle mixture screws, and the idle speed screw."

In other words, if you are running way too rich at idle then it is very likely you need to look at the air bleeds and idle feed restriction to change the A/F ratio at idle. Or easier yet, change to a different carburetor that more closely matches your application.

No question working with the carb is in order. It does sound like you have enough cam overlap so some unburnt fuel at idle is likley even if the carb is set up just right.

It also sounds like you have enough initial timing but it may be worth trying a little more - say 20 deg.

My B stroker makes some pretty good fumes even tuned with a wideband O2 sensor... but its a lot better than before I tuned it.

I have not tried upping the timing yet, but will give that a try..The engine runs great, just can let it idle long in the garage cause of the fumes. I have to test the PV or maybe change it also..I originally thought the jet size was the issue but found out that it has nothing to do with idling.
thanks for the info
al

just can let it idle long in the garage cause of the fumes. (quote)

Maybe your garage is too rich try adding some air flow in the garage.
( a small joke)
How does it run outside?
I was thinking the problem was while sitting in the car. You should not run the car inside without proper ventilation. AS IT CAN KILL YOU!
Maybe try hoses on the exhaust pipes like the shops do.

Well float levels are good the PV # is good enough to be closed. either the idle circuit is WAY off which I doubt if it could be causing this much richness or the PV is blown (common) or the gasket behind it has lost a piece (less common) or WAG could a piece of the carb be loose but my money is on the PV that it's blown. do holler when you discover what it is

Even if the PV is blown, it only adds fuel when the main circuit is in operation, not the idle circuit...

if so, first thing to do is get it to idle with the throttle blades properly closed (so the transfer slot is not exposed or even beyond).

Just curious, could it be the throttle base plate? I installed a Proform main body new floats, new jets, and converted it to a 4 corner idle..but the Holly base plate was never touched. Also trust me I have all the doors open, and even with a strong breeze the fumes are tough..can anyone explain the idle circuit?? the components involved? IE..power valve, jets ?? or is it the metering blocks?
thank you for your input..
al

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Just curious, could it be the throttle base plate? I installed a Proform main body new floats, new jets, and converted it to a 4 corner idle..but the Holly base plate was never touched. Also trust me I have all the doors open, and even with a strong breeze the fumes are tough..can anyone explain the idle circuit?? the components involved? IE..power valve, jets ?? or is it the metering blocks?
thank you for your input..
al

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Whoa! You need to do some drilling (and plugging) on the baseplate to convert to 4-corner idle. Do the rear idle mixture screws do anything at all?

But, let's back up. First, you must be sure your primary transfer slots are only exposed to the point that you see a square. Any more and you begin idling on the transfer circuit (or worse yet, the mains) and you'll have the rich idle you describe. Typically, this problem manifests itself when the initial timing is too low.

I can explain the idle circuit to you (the explanation a few posts up is good), but let's make sure the cart is behind the horse. Does your t-slot exposure look like the attached photo?