Why so many stuck throttles?

[Elkoldtimer]

I am curious about what causes stuck throttles.
Saw one at Ellisville in the vintage cars. Saw a couple on Speed51 coverage this year. The one at Sunshine a few weekends ago that ultimately led to the drivers passing. I think David Rodgers had one at last years Snowball derby also, not 100% sure.
The one at NSS yesterday is about the 5th one I have heard about or seen this past year- and I'm just one fan following a handful of races.
Is there any one cause or usual reason? I know the cars are pretty tore up so it might not be something that can be determined. Just seems like it's happened alot lately.

[Phil Jacques]

Seen a couple at Thompson during the World Series this past weekend... The cause? Air Cleaner rotated and caught the linkage... IMO It's really not that hard to rig up a simple wire or bracket to keep this from happening. Sure it takes a couple hours of time, but it's worth it if it saves your car and/or your life... Suck throttle is a scary thing. I also run 2 return springs in case one for some reason lets go... ALWAYS have a backup.

[andre]

Being very cautious on these points is No 1 precaution.

Secundo, if the stock car world would apply some of 2013 car technology to their weekly motorsports toys, maybe less of those would happen,. Technology to stop these things from happening is there in the open market, but the prehystorical rules or rulemakers would not allow them, for whatever reasons.

[Jack Burroughs]

Stuck throttles

Last night at N.S.S. it was announced that one occurred earlier that day.

[dd38]

The one's I've seen "Stick" or "Hang-up" are on cars that depend on a throttle stop in the lower portion of the fire wall and the foot pedal inside the car stops on it. They usually have a big washer as part of the stop. With the slop in some of the pedals I have seen this is possible. I had a friend who had that set up and the washer either was not big enough or the slop in it that portion slipped passed the washer and it hung up on the back side and hung open. My cars run the type of stop that bolts directly to the carb base plate and the throttle arm where the linkage hooks up stops against it. Double springs that don't loop thru the carb linkage and bent around but has a bracket both hook to and they are allowed to swivel as the throttle opens. And a air cleaner base plate with clearance no matter where it is rotated. MOROSO sells the stop and spring set-up. I heard a long time ago if Hamke built someone a turn key car he would not do the throttle linkage. It was up to the new owner.

[scottgarrity07]

There's only two things that scare me in racing. Fire and a stuck throttle. I have seen many cars have a stuck throttle due to "drop base" air cleaners. The air cleaner spins due to vibration and hangs the throttle wide open. As a result I will never run a drop base air cleaner (notice the air cleaner sticking throught the hood on my avatar). If you must run a drop base air cleaner here's a little safety "trick". On the top of the Holley carb there is a little notch. If you weld a little tab on the base of the air cleaner it will "lock" in that notch and keep the air cleaner base from spinning. Please, please do this. I never met Dennis but raced with him many times at Citrus. It really hits home that someone I have raced with is gone due to this. It just plain sucks and I can't imagine what his family is going through. As far as the throttle stop on the firewall deal goes, I agree, pass this up and use the one that bolts to the carb base sold by Moroso. If you must use one for the pedal on the firewall try this "trick". Use an automatic transmission mount for a mid 70's GM. It can bolt directly to the firewall and you can adjust the throw by using square tube and 2 bolts into the trans mount (no washers to hang up on). Hope this helps somebody.

[Lurkin]

Good stuff to keep in mind. Thanks guys.

[Darrell 76]

throttle

Through the years i've only had one stuck throttle (at NSS) IT'S SCARY --- now I run 2 springs in different directions , spring on bottom of linkage goes towards back of engine and spring on the top goes towards the front of engine , VERY unlikely anything will knock off both springs at the same time -----also throttle shaft/bushings will not wear on one side only ----- just my experience and thoughts

[ocalasp76]

11 years ago we lost a driver in the SLM division. Throttle stuck and I heard he was using a 'cable' type linkage. Hope no one is using them now... hard linkage and dual return spring on any car I drive... or I don't drive it..
My filter uses a spacer on top of the carb and when I spin the filter, I make sure there is NO contact to the linkage...
-JIM-