Sudden engine acceleration!

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Reds Skid Steers

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Apr 24, 2021
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Sudden engine acceleration.
As I was plowing snow with my 742B Bobcat Skidsteer, I suddenly had an abrupt speed up of my engine RPMs. I had not thouched the throttle handle at all. I'm looking for some ideas on what may have broke or happened. Thanks for any ideas.
 

mrbb

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Jul 19, 2016
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494
could be a fuel issue, maybe you had some jelled up fuel and it finally broke free and allowed proper flow again, making what ever throttle position you were at, NOW faster, or same like deal with a dirty fuel filter
or ICE in things and it finally melted after heat got to it?
 

brdgbldr

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Check your throttle linkage. All the way from your lever to the governor to the carburetor. There are a lot of connections that can come loose or wear out.

Also, check the oil in your governor.

If all of this is good, you could have a bad governor or a carburetor problem.
 

foton

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a vacuum leak can cause a engine to increase rpm, but i am thinking governor too.
 
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Reds Skid Steers

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Okay, I'm going to look into those issues. My machine is outside and it's so damn cold out. -14 degree wind chills today. So, I'm hoping tomorrow I can look into it. Thanks and I will let you know what I find out.
 

mrbb

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well you didn;'t mention you couldn;t lower rpm's, so, based my first reply on that trying top keep things maybe a simple fix for you
but old saying, better info you give us, better answers you will get, , HAHA!
Any how,

does your throttle lever MOVE and NOT do anything to lower RPM"S< or is it frozen and not allowing you to lower rpm;'s with the lever?
as that can have different solutions or possible issues!
and again, trying to keep it simple , based on your cold temps!

as if ice melts turns to water, and can drip onto things, and then re freezes else where, which it then can prevent things from moving,
but I agree with the others above too for possible problems!
Vaccumn issues as well as air bbeing cut off will cause a surge in RPM's, as ina blocked air filter , can cause things to rem higher! snow dust can black air flow, since you were plowing when this happened! so, could be a possible cause!
 
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Reds Skid Steers

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well you didn;'t mention you couldn;t lower rpm's, so, based my first reply on that trying top keep things maybe a simple fix for you
but old saying, better info you give us, better answers you will get, , HAHA!
Any how,

does your throttle lever MOVE and NOT do anything to lower RPM"S< or is it frozen and not allowing you to lower rpm;'s with the lever?
as that can have different solutions or possible issues!
and again, trying to keep it simple , based on your cold temps!

as if ice melts turns to water, and can drip onto things, and then re freezes else where, which it then can prevent things from moving,
but I agree with the others above too for possible problems!
Vaccumn issues as well as air bbeing cut off will cause a surge in RPM's, as ina blocked air filter , can cause things to rem higher! snow dust can black air flow, since you were plowing when this happened! so, could be a use!
Sure did mrbb. Said above couldn't control it with throttle lever! Throttle lever moves back and forth with the same resistance as always. I cannot control the speeding up with the throttle lever. Maybe broken, maybe frozen. I am looking into it tomorrow, and will let you know. My guess is either the throttle or the govener is the problem.
 
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Reds Skid Steers

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Apr 24, 2021
Messages
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could be a fuel issue, maybe you had some jelled up fuel and it finally broke free and allowed proper flow again, making what ever throttle position you were at, NOW faster, or same like deal with a dirty fuel filter
or ICE in things and it finally melted after heat got to it?
Not a diesel but sure could be the tank had some moisture and froze in the filter.
 

mrbb

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Jul 19, 2016
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494
Not a diesel but sure could be the tank had some moisture and froze in the filter.
doesn;t have to be a diesel to have water in fuel or fuel filter(if one is on your's) bad fuel can happen in any type, and many stations have tank issue's that you can get it from!
Also, if gasoline here, Fuel can go bad, modern ethanol gasoline fuel has a rather short shelf life!
 

mrbb

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Sure did mrbb. Said above couldn't control it with throttle lever! Throttle lever moves back and forth with the same resistance as always. I cannot control the speeding up with the
where??

your first post?

Sudden engine acceleration.
As I was plowing snow with my 742B Bobcat Skidsteer, I suddenly had an abrupt speed up of my engine RPMs. I had not thouched the throttle handle at all. I'm looking for some ideas on what may have broke or happened. Thanks for any ideas.
 
Last edited:

spitzair

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Dec 17, 2009
Messages
168
Most likely the governor belt either came off or broke. Governor sees this as a drop in engine rpm so it tries to compensate by opening up the throttle on the carburetor. The throttle lever in the cab essentially links to the governor telling it what RPM you want the engine at and it does the modulating of the throttle on the carb…
 

Wayne440

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Sep 24, 2017
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My guess, either lost the governor belt, or broke something in the governor. The former is much less costly to fix, do not over tighten the belt.
 
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Reds Skid Steers

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Apr 24, 2021
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where??

your first post?

Sudden engine acceleration.
As I was plowing snow with my 742B Bobcat Skidsteer, I suddenly had an abrupt speed up of my engine RPMs. I had not thouched the throttle handle at all. I'm looking for some ideas on what may have broke or happened. Thanks for any ideas.
Yes. But I should've been able to slow it down with my throttle lever But thanks.
Thats ONE of the first things I said.
Also, somebody said something about fuel. I said I don't have a diesel. And that's referring to the Jelling comment.
Read all! Geez louize, calm down!
 
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Reds Skid Steers

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For everybody else who is interested in not arguing. I fixed it. It was simple. Found the ball on the control rod for the govener had come off. Repaired and runs great.
Thanks all.
 

spitzair

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Dec 17, 2009
Messages
168
For everybody else who is interested in not arguing. I fixed it. It was simple. Found the ball on the control rod for the govener had come off. Repaired and runs great.
Thanks all.
Excellent, gotta love it when it's an easy fix. That explains why you couldn't throttle it down...
 

brdgbldr

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Jun 1, 2012
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For everybody else who is interested in not arguing. I fixed it. It was simple. Found the ball on the control rod for the govener had come off. Repaired and runs great.
Thanks all.
That has happened to me before. I was using a zip tie to hold it for a while. Once they wear out they will continue to come apart.

Bobcat still sells the swivel ball joints. I just replaced one on my 742B a few months back just before I sold it.
 
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Reds Skid Steers

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Apr 24, 2021
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Yes, brdgbldr. It was the ball on the govener broke I had to some rigging to get it back together and now she runs just fine. Thanks
 

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