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Discussion Starter #1
Tecumseh LH318SA-156554H
Start the motor on full choke, go to no choke, and it will overrev.
Adjusted both throttle screw and carb idle screw-no change
Adjusted throttle adjustment bar-all the way in, all the way out-no change
Adjusted linkage (bent)- no change

Is there something I am missing? Both the carb and the throttle are oiled and in good working condition where they respond to movement. It constantly overrevs no matter the situation.

What should I do? I bought this on a need to have, and now it isnt running right.
Help please!
Brian
 

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It could be a few things, I have a 5hp that does similar that the governor may need replacing but that one also does not speed up when loaded so the governor does not seem to working but yours could also have a air leak some place causing a lean situation making it rev.
 

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Discussion Starter #3
Pretty handy, dont mind a governor replacement. How difficult is that, and is it cost effective (or how would you test other than the way I am if a governor needs replacing?)?
How can I search for an air leak?
 

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if this is a 5 HP TEC, have you checked the linkage on the throttle and governor to insure they're hooked up correctly along with moving as they should?
That's where I'd start: insure they're correct and they move correctly. I did find a couple of pictures of a 5 hp I rebuilt and hopefully it might help such that it is.
 

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Discussion Starter #7
As a point of reference, even when I push towards the motor on the governor lever, so that would be towards a lower RPM, it really does not go low unless I press relatively hard on the lever, but even when you push without much force, it does not slow the motor down. That makes me think that it could be a governor issue inside....but, if I knew, I would not be asking!!
 

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Is it safe to say that the engine HAS NOT been disassembled at all recently, and that there's NO possibility that someone pulled the Oil Pan and didn't put the Mechanical Governor's Gear Shaft back together quite right ?
 

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Pulling the pan

Is it safe to say that the engine HAS NOT been disassembled at all recently, and that there's NO possibility that someone pulled the Oil Pan and didn't put the Mechanical Governor's Gear Shaft back together quite right ?

I can not confirm that. In the 3 months I have owned it, I have not. However, who knows about the previous owner. It had run rough, so I cleaned out the carb and it runs smooth, other than the overrev issue. How would you recommend making sure it "goes back together right" if I pull the pan?
 

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maybe un-hook the throttle from the governor and manipulate the throttle by hand. if you can control the rpms by hand then you know it is not a carb issue and it is a governor linkage or governor issue
 

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If it ran rough, but did not overspeed prior to the carb work, my bet is on a linkage or spring error on reassembly. The spring should pull the carb *open*, and the gov close it when speed is reached . . . Not always terribly obvious. Oh, and the throttle typically varies tension on the spring to set speed, so if the spring is in the wrong place or overstreched, you will overspeed as well.
 

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Discussion Starter #12
If it ran rough, but did not overspeed prior to the carb work, my bet is on a linkage or spring error on reassembly. The spring should pull the carb *open*, and the gov close it when speed is reached . . . Not always terribly obvious. Oh, and the throttle typically varies tension on the spring to set speed, so if the spring is in the wrong place or overstreched, you will overspeed as well.

Ok, so I checked out the placement of the linkage.
Started it in the current position-overrev.
Moved it to the position lower, (making the linkage have less pushing pressure in its position.)-Overrev.
When I play the linkage by hand, I have to push seriously hard to get it to not overrev, which is what one person said about the governor gear being improperly installed.

That is all I currently know.
 

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Discussion Starter #13
Is it safe to say that the engine HAS NOT been disassembled at all recently, and that there's NO possibility that someone pulled the Oil Pan and didn't put the Mechanical Governor's Gear Shaft back together quite right ?

Vermont-Any guidance on having to pull the gear when I pull the pan?
 

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A Harbor Freight Predator 212cc will fix that.
A Predator would make sense here but per the pic this motor has two output shafts (1 for impeller, 1 for drive) and a Predator has only one output shaft so he would need a new single dual-belt pulley and new belts, at the least.

I think someone has done this "2 to 1" conversion before?

.
 

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Discussion Starter #16 (Edited)

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Vermont-Any guidance on having to pull the gear when I pull the pan?
No, though I have the same Engine (LH318SA-156568H); I've never had to crack it open.

And I don't know any sure-fire way to tell if the prior Owner was ever in there (can you ask him if and why it was opened up ?). Barring that, I would consult a service manual for it. For smaller engines, Tecumseh emphasizes the distance the Governor Gear Shaft should be driven into the case, and that varies by specific engine.
 

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Discussion Starter #19
Well, I got bored today. I ended up pulling apart everything on the exterior engine side today to look around the linkages. When I pulled off the governor arm with the governor clamp, i found a small metal shaving between the clamp and the governor pin that runs down to the gear. From what I remember, this guy had been doing some metal work in his garage when I showed up to purchase. I am wondering if a piece did not get wedged and cause it to hold in an overrev situation. So, after all that, a simple metal shaving did the trick. No need to drop the pan. But in the end, a new carb, throttle and governor adjustments, and we have an operational machine again!!
Thanks all,

Brian
 

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It usually ends up simple on things like this (well, once you find it) and just about zero reasons to even begin to consider replacement. We are guilty of not asking how easily the gov armmoved when not running, or this would have leapt out at us! They typically have almost no resistance at all . . .

Glad you found it!
 
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