# Tecumseh 8 HP Over Reving all of Sudden



## Mike Smith (Dec 9, 2019)

Hello All

Tecumseh HMSK80 155487S

The Guy across the Street was snow blowing my driveway for me while I was away on a trip. All of a Sudden the engine started to Over Rev. 

No warning did not touch anything just happen.

I can work on Small Engines so tried over the phone to help him - He removed the Carb cover and could not find anything that Looked Broken or Disconnected from the outside.
Or snow packing someplace.

Since we had 22" Snow fall and needed a snowblower we went and purchase a new one.

I came home yesterday and went to look at it. As soon as you start it with the Throttle in Full Run it over revs right away. If you lower the throttle to the bottom it seems to run normal idle and sits there running Ok. Have looked at Videos and Read posts - see a lot on over revving - most are from people changing Carbs and not installing linkage correctly or adjusted the Governor incorrectly. Can find nothing on this Happening all of Sudden.

What do you think can cause this to happen all of Sudden? Besides Governor Failing inside engine - if that did happen is there a way to check from outside.

Want to try and eliminate all springs and linkages before opening the engine to check governor inside. Did not see anything that looks wrong or broken.
Checked round spring on Throttle it is there and works. I seen one video on tighten that spring tighter but do not know how this can make Rev all of Sudden.

Was thinking to remove the engine oil and look at it to see if find any metal or plastic that may come from inside governor. I heard the gear is plastic and can break in pieces.

Any help would be appreciated

Thank you


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## ELaw (Feb 4, 2015)

Any chance you can shoot a photo or 3 of the throttle-carb-governor linkage and post?

I will say that if really truly nothing was done to the engine and the problem appeared out of nowhere, it's likely the governor broke inside the engine. Those plastic gears are getting pretty old! If it broke you might find pieces in the oil, but they alsod may be large enough that they can't fit through the drain hole.

Another possibility that comes to mind is the governor arm slipped on the little shaft that comes out of the engine. I think if you google or look around youtube there are some videos that show how to adjust that arm on the shaft.

Oh and specifically to the point of testing the governor, there's really no specific way to do that. It's more a process of elimination... if the linkage is installed and adjusted correctly, the governor pretty much has to be the problem.


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## Mike Smith (Dec 9, 2019)

As soon as can get pictures will post - not sure when he will be home so can get to it. I know how to adjust governor linkage will do that too before re-posting pictures.


Thanks for help


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## Mike Smith (Dec 9, 2019)

Talked with him and he said he was going into heavy snow so was loading the engine up when happen and revved up.


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## Zavie (Sep 23, 2014)

Donyboy73 video on over-revving Tecumseh:


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## 1132le (Feb 23, 2017)

Mike Smith said:


> Talked with him and he said he was going into heavy snow so was loading the engine up when happen and revved up.



Sounds like the gov took a dump
or the set screw holding it tight is loose
readjust gov it takes 5 min there are vids on you tube if you have never done it
the arm should be slightly towards carb when adjusted right with the throttle on full
there are 2 ways to adjust it make sure you understand it
if still revs,and the carb linkage isn't farked up
the gov took a dump


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## paulm12 (May 22, 2015)

Mike: in your 2nd pic, is there a spring hanging from the linkage assembly that is attached to the shroud?


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## 1132le (Feb 23, 2017)

paulm12 said:


> Mike: in your 2nd pic, is there a spring hanging from the linkage assembly that is attached to the shroud?


Le 

I see no spring you mean the throttle cable


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## Mike Smith (Dec 9, 2019)

This snowblower has a Throttle Control on the front panel between handle bars - it does not have a leveler with red knob to control speed



I think you see the wire and the cover ( looks like spring) that goes to the throttle.


Click on the picture you may see better - if not that I do not see what you see


Thanks


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## toromike (Aug 20, 2018)

Mike Smith said:


> . . . Governor Failing inside engine - if that did happen is there a way to check from outside. . . .


here's how to get a clue of the condition of the internal governor (and how to reset gov arm)
https://youtu.be/TKvceEBaVH0?t=540


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## Mike Smith (Dec 9, 2019)

If you run a Engine with a Normal Governor inside ( not damaged) and full throttle 



Now you move Governor Bracket with you hand and move it back so less Rpm or open for more Rpm - 



What would you feed on the arm if anything the engine is trying to do?


Now say you have a Broken Governor and you hold it so idle so does not over rev - would you feel the arm give more resistance.


Trying to determine if you can tell with resistance or no resistance of Governor Arm so can tell if broken inside or not.


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## notabiker (Dec 14, 2018)

Make sure the shaft isn't spinning on the governor to throttle linkage first off.



Then start the engine and leave it running at an idle. 



Push or pull on the governor arm so the engine speeds up, the governor inside should fight your movement to lower the engine rpm to around the max which is probably 3600 rpm or so. If you don't feel any resistance and the engine is screaming then the governor inside is broken or somehow slipped out of adjustment.


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