Throttle moves down on own

[Panther416-8 341]

So I put a new carb on the 16 horse Kohler Magnum and now I have an issue with the throttle lever. As it is running the lever keeps moving down by itself, it doesn't stay in the high position.  I had no issues with it before replacing the carb. Any ideas what to look for? The clamp that holds both the choke and throttle cables in the front of the engine is tight.

[Snoopy11 5,714]

Can we have some pictures of your setup?

 

Side question (just in case) Do you have any little springs in stock @Panther416-8?

 

Ones like this...

 

 

Don

[The Freightliner Guy 1,327]

Does it have enough tension or to little tension 

[pfrederi 17,741]

If the throttle handle moves very easily take it out give the pivot a couple whacks with a hammer while blocked against something ...or drill it out use a bolt and nylock nut

 

 

 

[peter lena 8,634]

@Panther416-8 

after freeing up my throttle / choke  cables , using  SUPER LUBE OIL , in the cables and related linkage , use some perforated  steel on existing mount spots to add  light spring pull on the cable . lever areas , EXPERIMENT FOR EFFECT  , did that on 1 kohler magnum,  soon adapted it to all 3 .  cables / levers , do not creep , solid / smooth . pete   

[c-series don 8,719]

My 416-H does the same thing. I tried squeezing the pivot point with vice grips but it didn’t help. I’ll have to try @pfrederi’s idea and take it out and smashing it! 

[peter lena 8,634]

@Snoopy11  sounds wrong , but those springs actually assist  closing those cables , as I  experimented with them , the best effect was on the pull to close side . cables and related levers and movement points were lubrication  smooth with action . just went back and forth with engine off  function , started up , and it was like magic , smooth easy response , and zero throttle closure , years and lots of hours , still good. pete

[pacer 3,173]

I suspect @pfrederi solution will be what you will end up having to do. It works strictly on friction and with age it slowly loosens. Hopefully a "whack" will tighten it up, but just may have to put a bolt/washers there.

[Handy Don 12,233]

On 9/22/2022 at 3:36 PM, pacer said:

I suspect @pfrederi solution will be what you will end up having to do. It works strictly on friction and with age it slowly loosens. Hopefully a "whack" will tighten it up, but just may have to put a bolt/washers there.

I'm a fan of a shoulder bolt, flat washer, and nylock nut (with all the original washers and spacers in their original positions).

The shoulder keeps the pivoting lever and bracket from getting worn by the sharp threads and the nut lets you adjust the friction to your liking easily.

[Rick3478 428]

On 9/22/2022 at 1:24 PM, c-series don said:

My 416-H does the same thing. I tried squeezing the pivot point with vice grips but it didn’t help. I’ll have to try @pfrederi’s idea and take it out and smashing it! 

I've used the vice grip method myself with success.  You have to use a large one to get enough mash on the rivet.  The advantage is that you don't have to take anything apart.  Bolt & nut is probably best long term.

[Bill D 1,923]

I've used a grade 8 bolt and nylock nut or all steel lock nut.  I also replaced the fiber friction washers with plastic washers.  The original fiber washer broke.

[Handy Don 12,233]

16 hours ago, Bill D said:

replaced the fiber friction washers with plastic washers

The friction washers are an essential part of the function, for sure.

[Bill D 1,923]

39 minutes ago, Handy Don said:

The friction washers are an essential part of the function, for sure.

Plastic washer seems to be working fine so far.  

[Handy Don 12,233]

2 hours ago, Bill D said:

Plastic washer seems to be working fine so far.  

Not surprised, though some "slippery" plastics would likely need extra tension.

[Panther416-8 341]

I drilled out the large rivet as per @pfrederi using a 1/4" bit , kept the fiber washers and used a bolt and nylon lock nut. Works perfectly now, stays wherever i set it. Thanks all for the suggestions. 

[peter lena 8,634]

@Panther416-8 looks like a simple fix to me , as with anything  I  go after to repair / fix  look at total function , anything / everything  that's part of  intended  set up . another thing I  do , is to go after cable lay out , put it where it wants to be , any forcible bend , stiff spot will effect slide.  add a few cable clips , to mounting spots , super lube oil . notice your battery ground rail , next to battery , good spot to tie into battery ground bolt point , for enhanced , verified  electrical grounding . add a battery cable / or electrical lug , to trouble spot , headlights , rectifier , amp charging reaction ,  also a pto lever start spot that can be improved . pete

[OldWorkHorse 3,045]

Have the same issue on my 314-8 throttle will slowly slide down to about 2/3 throttle. Been planning to fix it but havnt looked into it much, guess I found a solution and my next small project. 

[gwest_ca-(File Mod) 11,046]

The throttle cable increases the rpm.

The governor tries to reduce the rpm. The faster the engine runs the more force the governor develops to reduce the throttle opening.

That is why the throttle crepes back most at high rpm.

[kpinnc 12,082]

My 520-H does the same thing. I never considered adding a bolt and nylock. That's a great idea, and I will be doing this myself!

[peter lena 8,634]

@kpinnc local H/W store  probably has  small pull out drawer section with those  slide washers , probably also has SUPER LUBE in a 6 oz bottle , made for cabling  function. use that on all my cable / linkage / lever areas , pete 

[gwest_ca-(File Mod) 11,046]

1 hour ago, kpinnc said:

My 520-H does the same thing. I never considered adding a bolt and nylock. That's a great idea, and I will be doing this myself!

Use a bolt with enough unthreaded shank to go all the way through the assembly plus a bit. Add flat washers to the outside so the nylock nut has room for future adjustment. You can reach in with two wrenches to adjust as necessary.

[Horse Newbie 7,071]

On 9/22/2022 at 12:28 PM, pfrederi said:

If the throttle handle moves very easily take it out give the pivot a couple whacks with a hammer while blocked against something ...or drill it out use a bolt and nylock nut

 

 

 

Because my throttle knob did not want to come off easily and I was about to tear it up, and the fact that to drill it out you have to probably take the throttle lever mechanism completely out to drill it, I reached in there with some vice grips and squeezed the pivot rivet a little and that made it tight enough to where mine on my 520 H stays where I put it now…

Edited September 27, 2022 by Horse Newbie

[peter lena 8,634]

@Horse Newbie  think most important thing you can do is to go over every  intended movement point , what I  do on cables is to unhook  from carb , does it move easily / smoothly ?  often cables were clamped down , where they do not want to be , loosen up hold downs , lubricate , if any binding is suddenly gone , you are on track with cable base setting. I  go the opposite way  of force , detail and enhance function . just an idea , pete