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fishnwiz

Purpose of spring on throttle linkage ?

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fishnwiz

Just curious on what purpose the fine spring serves that is wrapped around the throttle linkage between the gov and the carb? Most times these are not attached anyways. I can't see the reason for it. Can someone please explain? Thanks

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Talntedmrgreen

None of mine have the spring...most I've seen have it missing or unhooked. Only one tractor gives me trouble though, and that's the WB700. That old 3-bolt carb is a bit loose from use, and I need that spring to hold things steady. The butterfly is going crazy in there at anything above an idle, from the virbration of the engine, causing the linkgage to jump around.

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cojomu

I have an old Broadmoor 5008 series that has this same situation, the spring is just hanging on the linkage, not attached to anything. I've looked to see where it attached at the throttle controls but can not dteremine where. From what i've been reading on this topics, it really doesn't matter....right? There is so much play in the carb from wear that it is drawing air around the butterfly rod. JB Weld has helped close it up some, but this carb really needs to be put to rest.

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fishnwiz

It seems that air leakage on a worn throttle shaft is more to blame on surging then a missing spring. Just curious on how you can close the throttle shaft hole without sticking JB weld to the shaft?

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GrincheyOne

I have to agree with "all above", since both the governor arm, and the throttle lever have linkage holes without bushings, and the throttle rod has too much space in the bends at the ends, this spring does make the linkage more stable. One end attaches to the governor arm (sharing the same hole as the throttle rod), and fastens to the throttle lever via the small hole in the lever. care must be taken to not stretch or deform the spring in any while installing (or it looses effectiveness).

This spring, along with proper adjustment of idle air-fuel mixture, governor arm on it's shaft, and the manual idle screw, will minimize the surging of the engine. NOTE - the use of a light weight oil, applied to the spring and throttle rod, will help keep the spring from binding on the rod.

Cheers,

Wayne

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cojomu

The way I applied JB weld around the butterfly shaft was, I took a plastic straw and place it over the end of the shaft. Then I applied the JB weld around the straw and onto the carb housing. After it dried I cut the straw down and it became sort of a bushing on the shaft. This closed up almost all the worn area. As for the other side of the shaft where the throttle rod attaches, I applied JB weld all over end and when it dried I took a dremmiel and ground off enough to free up the shaft. Is working, don't know for how long, hopefully until I find another carb.

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Brettw
The butterfly is going crazy in there at anything above an idle, from the virbration of the engine, causing the linkgage to jump around.
id="quote">

These two statements reflect at least one reason why the spring is in place. A worn throttle shaft comes from movement. If the carb sat on a bench for a hundred years, it would be like brand new and not worn at all. If the shaft is rotated and moved a thousand times a day, every day, it will wear out. So it only makes sense to realize that, if the shaft is "bouncing around", moving back and forth hundreds of times or more per minute, in addition to normal use and rotation, logically this absolutely has to increase wear. If for no other reason than just to prevent this, the spring is a good idea, and was engineered to be there for a reason. Considering it is on countless engines, designed and redesigned by teams of engineers over years and years, says something too.

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Talntedmrgreen

I think that pretty much says it all...i have a rubberband wound on mine as a sort of shock absorber, to temporarily minimize the bounce/wear. It was all I had on hand at a show and worked well for the day.

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dlsven

For what it's worth I've been working on my 7116H after not using it for about 4 years having been left with old gas in it. I got it running pretty good by running Seafoam through it a few minutes for a few days but it would die whenever a load was placed on it. When I hooked up the spring on the governor rod it cured that problem.

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GLPointon

Ditto...well said BrettI always say "Don't try to out engineer the engineers". If it comes with it...I use it. Even if I dont know why (which is often) sm00

Originally posted by Brettw
quote:
id="quote">These two statements reflect at least one reason why the spring is in place. A worn throttle shaft comes from movement. If the carb sat on a bench for a hundred years, it would be like brand new and not worn at all. If the shaft is rotated and moved a thousand times a day, every day, it will wear out. So it only makes sense to realize that, if the shaft is "bouncing around", moving back and forth hundreds of times or more per minute, in addition to normal use and rotation, logically this absolutely has to increase wear. If for no other reason than just to prevent this, the spring is a good idea, and was engineered to be there for a reason. Considering it is on countless engines, designed and redesigned by teams of engineers over years and years, says something too.
id="quote">id="quote">

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GLPointon

Ditto...well said BrettI always say "Don't try to out engineer the engineers" if it comes with it...I use it. Even if I dont know why (which is often) sm00

Originally posted by Brettw
quote:
id="quote">These two statements reflect at least one reason why the spring is in place. A worn throttle shaft comes from movement. If the carb sat on a bench for a hundred years, it would be like brand new and not worn at all. If the shaft is rotated and moved a thousand times a day, every day, it will wear out. So it only makes sense to realize that, if the shaft is "bouncing around", moving back and forth hundreds of times or more per minute, in addition to normal use and rotation, logically this absolutely has to increase wear. If for no other reason than just to prevent this, the spring is a good idea, and was engineered to be there for a reason. Considering it is on countless engines, designed and redesigned by teams of engineers over years and years, says something too.
id="quote">id="quote">

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