440 Six-Pack: Throttle spring doesn't seem strong enough

[Grec]

Six-Pack is up and running. Woohoo!

One issue I'm seeing is the throttle not returning to idle after having given it gas.

ie. you start out at 1000 rpms, give it gas and let off of it and it goes back down to 1200 rpms.
(these aren't exact numbers as my tach isn't hooked up but you get the idea :-)

If you manually pull forward on the throttle it'll go back down to the correct idle.

Note: there is no more adjustment in the idle adjust screw.

Questions are:

Is there a stronger spring made?

Does it take a bit to get the carbs worked in? I've only run them for a total of an hour or so and maybe driven it 3 miles so far.

As always, any help is appreciated!

[gkring]

unhook the rod to the outboard carbs and try it. You probably have them misadjusted a turn and they will hang open the throttle slightly.
Also check the gasket from carb to intake, it will fit on backwards, but barely hangup in the throttle blades. The only other thing I have ever seen is overtorquing the carb bolts causing the shaft to bind a little. Good luck

[Chryco Psycho]

you could also have a small vacuum leak keping the idle too high ,I recommend using a double spring at all times in case 1 breaks

[Grec]

Thanks for the tips...

If In recall correctly, my vaccum was reading around 22-23 after I adjusted the timing and mixture. Does that sound about right?

Where would I get the double spring you mentioned? That's a good idea anyway as the motor will go right to full throttle if that thing ever loses tension, right?

That could be messy. :-)

[Chryco Psycho]

wreckers will have double spring sets from other Mopars