I tried this dual coaxial compression spring setup but it feels like crap and is really hard to push. The carroll smith books like a compression spring because if it breaks, you still have some spring action.

How do you guys rig your throttle return springs on IDF's?

Also, does it help to lube the inside jacket of the throttle cable?

thanks,
dr

neat trick i saw at dunkels was as follows:

loop one end of a 'pull' type spring to the side of the aircleaner base, and the otherside to the extra hole on the arm on the weber throttle shaft

Aircooled.net sells little springs that go on the carbs themselves right at the throttle arms, and are good backup if your main tension spring breaks. I used those, and a simple tension spring between the arm and one of the trunk springs. Not too heavy, and three springs have to break for me to have stuck open throttles.

That "coaxial" spring is useless if your actuator arm breaks or falls off the carb. The return spring should be mounted on the carb shaft linkage - use two if you are uncomfortable.

take a side view pic of your carb attached to the linkage (middle of engine bay - looking at a carb) and ill show you the easiest solution.

OK,

thanks aaron, I looked at them and couldn't figure out what you were talking about....

dr

DONE: your welcome
loop end of spring on the air cleaner base, put other end of spring in the hole on the arm ... SIMPLE and EFFECTIVE!

I like to have the coil springs on the IDF throttle shafts, and a long, small wire gauge, pull spring attached to the same arm the cable is on.
It may take a few tries to get the correct tension so the pressure at your foot is reasonable.

I don't like the springs that attach to the filter plates, btdt.
I don't think the compression spring will work out; it will cause too much slack on the cable.

My P-tech installed some small pull springs on the throttle shafts to the filter plate (already had coiled up springs on the carb shafts). I immediately removed them. WAY too much pedal effort. I like just one longish loose spring on the hex bar.

Of course, when it comes to switchin'off the ignition, I'm pretty quick on the draw.

Your engine bay is looking good. How about a few picks of all of it?

Just a quick question....When you run the throttle cross shaft in front, it looks like you need a longer throttle cable to run it in from the rear?

Where do you get such a cable?

I also tried the small springs from the throttle shaft to the linkage....the springs were holding my throttle plates open (binding)...

Thanks, herb

Do not put a spring on the opposite end of the throttle shaft from the linkage. It will induce a slight amount of twist in the throttle shafts causing a stumble upon throttle opening. I used to run a center pull linkage with a return spring mounted on each carb that pulled back to the chassis. Worked better than many other setups.