why would a carburator start burning my eyes???????

[billyd21970]

i have a 13 to1 406.i have a brodex intake and bow tie heads with 208.im running a 618 roller cam.with a quick fuel 850.its all new and first got it running it was running fine.but after the 6th pass it has started running rich and burning my eyes.any help fixxing it.

[coloradoracerguy]

What is your fuel pressure set at? Where are your floats set at? Do you have fuel coming out of the boosters while idling? What are the idle mixture screw set at? What is your initial timing? Need to know more about setup before we can help. Lots of things can cause that to happen.

[billyd21970]

fuel pressure is set at 7 1/2,floats are set at the bottom of the sight holes,no fuel coming out the boosters,the fuel mixture screws are set at 2 turns out both front and rear.timing at 36.

[TS1955]

Does your carb have a power valve?

TS1955

[coloradoracerguy]

IMHO, I think your mixture screws are too far out. They should be between 1-1 1/2 turns. How much transfer slot is showing on your combo? Do you know what air bleeds you have in it? Idle feed restrictions?

[billyd21970]

i have tried them at 1 to 1 1/2 to 2 to 2 1/2 turn. and it does have a power valve.it a number 4.not sure how to check it if it bad.

[coloradoracerguy]

How does it respond when you change the mixture screws? You might have a pv issue. Pull it out, and try to blow through the flat part. If you can blow through it, it's bad. Gonna taste like crap though...... :shock:

[billyd21970]

ill try that now.i have it apart.so it taste as good as it smells?lol

[billyd21970]

i tried to blow throw it and nothing.

[billyd21970]

the pv 4.5 and the front jets are 78 and rear are 84..

[coloradoracerguy]

So how much effect does adjusting the idle mixture screws have? At what point can you get the engine to stumble/die? Is it only rich at idle, or is it rich at part throttle and going down track? Trying to get it narrowed down as to where it's fat. My guess is something is blocked or stuck open. While you have it apart, make sure to blow out EVERY passage in the carb with carb cleaner and blow it dry with air.

[billyd21970]

all rmp ranges.its just burns your eyes and takes you breath.it will leave black marks on the ground where its sitting running.they say going down the track its blowing a little black smoke from it.its just wierd that it just got worse and worse.it was good when i first got the car going?

[zipper06]

Have you changed the spark plugs since you got it running, and what gap are you running? You might want to go 1 step hotter on the plugs, also run the gap about .026/.028 Alcohol eats plugs pretty fast.

Just a thought.

Zip.

[coloradoracerguy]

Time to take the carb off and take it apart. You need to inspect EVERYTHING. From the sounds of things, you're leaking fuel internally, but no way to be sure until you check. Pull all bleeds and everything else out and blow everything out with carb cleaner then air. Somewhere fuel is getting in and it shouldn't be.

[jmarksdragster]

Make sure the timing is locked to full advance, and you are running a plug heat range equivalent to an NGK7 and not colder. Timing should fall from 34-37 if they are Iron Bowties, 1-2 more with aluminum.

[murrayjest]

Do you have fuel coming out of the boosters while idling? What are the idle mixture screw set at? What is your initial timing?