Need advice from Carb Guru's

[kurtnkegger]

Trying to get my timing adjusted, and idle set, but the idle on the timing gun fluctuates a lot. It vary as much as 75-100 RPM, and never stays constant on the tach through the gun.

Looking down the air horn, there is fuel that sprays (more of a pfft, pfft, pfft) down tha barrel nearest the accelerator pump, and of course the idle fluctuates when this happens.

I don't recall seeing fuel there at idle, but never really paid attention before, and it's been quite a while since I had a carbuerated fuel system. Do I have something stuck in the carb causing this, or is it normal? Should I have more of a constant spray?

The fuel I see isn't a fine mist, but more of a "spritze" for lack of a better word.

Any advice would be appreciated....

1977 2F motor, original carb.

 

[Splangy]

First of all, you're idle is set too high if you have fuel flowing from that nozzle. During idle, you should only have fuel leaving the idle circuit at the base of the carb.

 

[kurtnkegger]

Thanks Splangy,

Here is a you tube video of the thing running...What should my idle be set at? I thought it was pretty low as is...

Any more advice is appreciated.

YouTube - 045

 

[destin]

i could be speaking from out of turn, but I set my timing at an idle of 650 rpms.

While are carbs are likely different, if you have fuel coming out of the accelerator would that mean maybe your metering rod is maladjusted so it is letting in fuel when it should be running outta the idle circuit>?

My 1f carb the metering rod fits into the metering jet until the accelerator rod/ pump mechanism pushes the metering rod deeper into the metering jet/check until fuel can come out of the accelerator jet tube..

Again are carbs are likely dif.

Do i hear a knocking in that video? or is the camera just picking up extra noise?

 

[kurtnkegger]

I definately have a tick...I wouldn't call it a knock...the camera was right on top of the valve cover, so probably picked up extra noise.

I'll check in to that mtering rod adjustment as well.

 

[Pin_Head]

If fuel is coming out of the main nozzles, the idle speed is set too high, probably because it won't idle otherwise because of an intake manifold vacuum leak or a lack of idle fuel (non functioning idle fuel cut off solenoid).

Check for manifold vacuum leaks and check the solenoid for proper function.

 

[kurtnkegger]

Thanks everyone for your input. I checked the idle solenoid, by jumping the positive battery post to the plug. It clicked, so I'm assuming it works properly. Also checked the voltage feeding the solenoid, and get 12 volts there when running.

I started turning down the idle speed screw, and alternated the idle mix screw until I was at 650RPM. Once that magic number was achieved, the spritzing from the main stopped.

I'm running at about 3 to 3 1/4 turns out on the idle mix screw. I don't know how many turns in I am on the speed screw...moved it about 1/4 turn out though.

I didn't check for vacuum issues...My vacuum was about 15" on last check.

Are 3 to 3 1/4 turns out acceptable?