@Literati914 , The one you linked to is the correct one. I clicked through and looked at the other options to be sure. You picked the right one in the first post.
There isn't a spring that works with our direction of rotation.
@Tbrown4x4 , if you have one of those installed, take it off -- unless you're absolutely sure it's pulling the throttle closed. But I looked at a lot of options and could never find spring that was compatible. The 914 is the only car that has the accel cable come from the fan side of the engine. So we're the odd-man-out. If you
NEED help making the carbs close, add helper springs at the throttle shaft, one on either carb. Make sure the springs are exactly the same and installed in exactly the same way to ensure equal action.
BUT if you're having trouble returning to idle, you need to inspect and address the following places, and you must do ALL of them because their resistance is additive -- one may not be a problem on its own, but all together they become sticky.
-Throttle Pedal: If it's not new, maybe it's time. The rubber around the base hinge is intended to aid in throttle return. If it's torn, it can't do that. The hinge itself is meant to move freely and without wobble. If it's rusting inside, it'll add resistance.
-Pedal Cluster Bellcrank: If those little bushings are worn, they can add resistance. They need to be clean, greased, and unworn.
-Throttle Cable: Make sure it's not twisted around the clutch cable first of all. And the
most common issue I see with throttle cables is where they protrude from the firewall under the engine. If this area gets even slightly, imperceptably kinked it'll cause a problem. If the steel tube-guide pops off, it's done for -- even if you push it back into place. Now I
always pull the steel tube-guide bit off the body accel tube at the firewall when removing the engine specifically to avoid this type of damage to the cable. If in doubt, replace it.
- Throttle Cable Tube: The center tunnel guide tube can have rust in it, can have wear marks, can be bent or broken. The front few inches is the most critical. If that has broken off and been repaired poorly, it can cause a tight spot. That tight spot will increase friction and will quickly erode any plastic liner or even the tube itself. If there's a groove for the cable to sit in, it will increase resistance to movement.
- Throttle Shafts: Finally, the throttle shaft in carbs can be sticky as well. Disconnect your linkage and feel for any sticky action. They should snap closed on their own when released quickly.
AND they should move closed of their own accord when gently and slowly returned to closed. And stickiness in this motion will add to the resistance.
It's a bit blunt I suppose, but every piece from your foot to the carbs needs to be moving 100% within spec in order for the throttle to operate like it should. This is the 'trick' for old cars. You simply can never ever assume anything is as it should be. Even if it 'seems okay'. Adding closer springs to the carbs or the linkage are really just band-aids. Springs can cover it up, but the true problem is in all the other pieces.