My throttle won't snap back. I recently packed the end of the handle bars with silicon to help with vibration. Now my throttle sticks and won't snap back right away. How can I fix this?

if you take off the bar ends. fill the inner of the bars with silicone sealant. use a tube to get in. this is a cheap and light way of getting rid of vibration.make sure you refit bar ends before silicone cures. i use this method on my race bike, i used to get pins and needles. not any more.

Throttle cables got crushed or kinked by tie downs or throttle grip housing crushed. If that doesnt help check the housing that the throttle cables turn in to make sure the barrels at the grip end of the cables are seated correctly. If that fails check the push pull at the throttle body to make sure the cables are in the grooves. I'll bet it was the tie downs doing some damage at the handle bar area.

To make a throttle cable or any cable you have to have both ends fixed to the same bar. IT cutter shaft mount bar mower handles etc otherwise the inner won't move as when you push the throttle the outer moves and not the inner.. By you video you need to fix this first.

z_dogg, you do not need new carbs. Several issues may cause throttle sticking, and all of them are cheaper than a new set of carbs. Introducing a used set of carbs just introduces a new unknown set of potential issues.
This approach moves from easiest to most involved solution.
First, take apart the throttle at the handlebar. Clean the throttle tube, the part you twist to accelerate, and lubricate the throttle tube and throttle cable with penetrating oil like WD40. To get the lube into the cable I use a finger from a rubber glove with a small hole in the tip, slip it over the cable end and fill it with lube, then let it seep down into the cable. Best results ever. Re-assemble this end and test your results.
Second, if it is still sticking, check the cable routing. Often the cables get bent or twisted and cause binding that prevents free release. Make sure the cables are routed with no sharp bends, and the largest curves possible.
Third, disconnect the cable from the carbs and move the throttle linkage itself. If it snaps back into place, it is the cable not the carbs. If it does not snap back, lube the linkage at each carburetor while moving it and see if it frees up.
Fourth, if it still sticks, you will need to pull the carbs and clean them thoroughly inside. It may be the vacuum slides that are sticking open and keeping it from slowing down. It would be best to invest in a manual to guide you through this process. It can be done with a few cans of carb cleaner and careful handling of the parts.
All the best in your repairs!

they can stick in a number of places.
You may need to dissassemble the hand throttle assembly
Make sure the plastic twist grip turns freely on the handle bar.
Check the new grip doesnt push against the throttle switch assembly.
Check the cables move freely
Check the cables dont have any frayed ends
check the cables arnt missing any of the plastic outer cover
check the cables a routed correctly and dont get jammed or pulled turning lock to lock

adjust the cables to were they are as loose as possible. one cable should be for snap back and the other for the actual throttle. you will have to put the housing on the bars and the throttle sleeve on the bars, then install the cables in the throttle sleeve.

no spring in the grip!
id suspect the cables are binding up inside so disconnect at the carby end then & see if they are moving freely
Cheers Rob

sounds like tie rod ends with the shaking.check struts and sway bar links on the snapping. hope this helps you.

You may have over tighten the screws. try backing them out then when they are snug give just another 1/4 turn. Try that and see what happens. you may have to open it all back up and make sure that the throttle cable is not binding.

Hi pl427
I love these bikes. Vertical twins of this era vibrate, is just how it goes. Engine design was simple back then and no counter shafts are used, so there is a degree of vibration at low revs produced by 2 big bore pistons that will make the handle bars get a real bogey on at idle.  If the carbs are out of sync,or need a tune, then you may have a lazy clyinder at idle that is producing the vibration also. Not sure if your bike has them, but some have rubber bushes that mount the handlebars. These can get sloppy with age and may need to be replaced. Another trick if the vibration is anoying you is to mix some lead shot with silicon and fill the ends of the handle bars up to "weight" them and reduce the vibration.
click here to see one walking on its center stand. Notice the way everything is vibrating on this old girl. 
regards robotek