dual carbs, one return spring or two

my duals have 1 return spring on passenger side. lately the car doesnt go back to full idle. nothing rubbing, greased all the moving parts, throttle wire thru firewall etc. i even shortend the spring a little. should there be a return spring on each carb or is there a better way or place to hook spring.

Could it be your idle need adjusting? I have had this happen a few times over the summer and adjusting the idle screws set's it right where it's good. The only thing I could think is that one of the screws slowly turns a touch enough to FEK-up the idle. I open the right carb so it's really not working (touching the cam) and adjust to 1000 rpm with the left and then go back to right until it's a little over and back it down slowly to see it at 1000 on both.

Could be the same on yours.

I'd recommend a return spring on each carb.

Warm the engine up (take a ride to Starbucks and back).

Sitting in the driveway and with the engine idling, note the idle speed.

Now....quickly tap the gas and immediatly let it off (we call that "blipping" the gas). I mean it - tap it with your toe....just a "blip", but push it 1/4 way or so (the distance isn't that critical). Do it JUST ONCE.

What's it idling at after that? Same? Higher? Lower?

Let me know.....

Then...how, in general, does it idle? Smoothly? Uneven? Does it hunt around (changes idle speed at random)?

Report on that, too.

Thanks, gn

car returns to perfect idle 50% time,,,it is not the idle speed adjustment screws...everything is greased and nothing rubbing...i need another spring on other carb or a bigger spring on the one...is there a better place to hook spring onto other than carb..

Two springs will keep the cross cross linkage controled on both ends and prevent the possibilty of one end being slightly different from the other.......Tomlinson reccomends 2 "light" springs over a single heavier sping.....Throttle should snap home when released without undue foot pressure required for operation.......Just a thought...

Most carb guys suggest springs on both carbs. It will prevent uneven wear. But the problem may be unrelated to the springs. Have you checked your throttle cable? If it's too tight it could cause this problem.

Looks like the general concensus is run dual springs. Sounds like one side or the other isn't fully returning (it doesn't take much to hold it off the idle stop) and messing you up.

You might also look into a slightly stiffer pair of springs, too, but don't go nuts or you'll end up with a stiff pedal.

Most hardware stores have a spring tray with a number of different lengths and tensions. Find something that looks like it'll do the job and try it out - they're cheap.

gn

Bob -

As with the general consensus, I agree with the two return springs gig. But as Gordon alluded to, don't get too carried away with a spring tension that is too much. It would put additional/undue duress on your throttle cable. Don't ask me how I know (pic).

Actually, if it doesn't already have one, it would be a good idea to convert your throttle cable to a heavy-duty cable as used on dune buggies and a generous application of lube at friction points.

Good luck with your project!

I see that Jimbo is using some of that Hemp-based, accelerator return material.

Once you get done harvesting, you can use what's left for linkage repair....