Briggs 44R877-0001-G1 - Max Rev on startup

Patra

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The Briggs 44R877-0001-G1 is a 24hp Intek V-Twin sitting in a Husqvarna yth24v48 mower (from Lowe's).

The mower sat for a while and at first I couldn't get it to start and realized a rat had chewed wires, not allowing me to start the mower. I fixed that, then the starter would work but the engine wouldn't come on. That started my journey, ending up in taking out the carburetor and cleaning everything out (there was indeed gunk in it, also causing the solenoid to get stuck, etc.).

Now it will start easy, but the engine revs at maximum throttle only. I also discovered that the throttle cable had come unseated at the lever under the dashboard, so it would move the cable housing along with it when adjusting. I fixed that so the throttle assembly under the carb works again. So I played with the linkages, governor, checked all the springs, etc. Whatever I do -- and I mean WHATEVER I DO -- when I start the mower, it revs at maximum. The RPMs are so scary high, I turn the mower off right away because I feel it's going to blow if I don't.

So I started thinking along the lines of the governor internal parts being messed up, but I want to make sure I have done all I can outside the engine before going there or having someone go there (tight budget). The mower literally has less than 20 hours on it, but it's 3 years old and so it sat a lot. However, oil was new, looks great and clear still from the other year. Installed a new fuel pump (the old one was actually fine), cleaned carb real well, no missing screws on butterfly. Have played with various spring tensions, throttle cable adjustments, loosening governor arm and tightening it with throttle full open (all the way down), what have you. But whatever I do, it starts with very high RPMs. As far as I can tell there are no hose leaks either.

So then I was trying to see what happens when I start the engine, having someone else start it while I sit in front of it. I notice the governor arm is not moving all the way up when it starts. So the linkage is not moving the carb air intake into the closed position or low idle. I was able to push up the governor arm / carb linkage and that DID lower the RPMs. But there was only a small window there, it was either low RPM and not a very smooth running of the engine, or it was full blast RPMs when I lowered it just a bit. So I CAN control the RPM that way, but why is the governor arm not moving up by itself?

When I just look at the governor arm while starting, it does move up a bit, but not all the way to idle position.

Any help is appreciated!
 

bertsmobile1

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Either you have connected the governor backwards or the governor is broken internally.
From what you have said I rather think it is the former.
At rest the throttle should be fully open and if you push on the governor arm it should close the throttle down.
If not then it is adjusted wrong.
If when you push it closed there is no movement then the spring is in the wrong position.

Some photos would help.
 

ILENGINE

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Almost make sure the throttle rod in the carb turns freely. I have seen them get sticky after the carb sets for a period of time, and since the governor when not running holds the throttle in the wide open position it will stick in that position.
 

Patra

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Thanks, guys.

Well, the governor is now in the same position it was in when the mower was functional. I took before and after pics to make sure I did it right. I've also tried all possible combinations of governor rod setting (left, right -- it has to be right/clockwise with open throttle), and throttle cable handle settings (turtle/rabbit), etc. But nothing I do even makes a difference, it's always wide open.

To help, I attached some pictures to this post of what the throttle / choke assembly looks like.

Here is a YouTube video I uploaded of what happens when I start the engine. The engine runs wide open even if the phone mic self-adjusts, but trust me, it's scary open and I have to cut it off immediately or I feel it's gonna blow. As you can see in the video, the governor arm does go up but not all the way. I've tried both loosening and tightening the governor springs to no avail. Last night I had someone start if for me while I sat in front of the engine and once started I was able to push the governor arm / throttle linkage upward and that DID lower the RPMs. Also see the description in the video:

https://www.youtube.com/watch?v=U8SisF4S9hY

Thanks!

EDIT: made another video of what the choke assembly (?) looks like and how it functions. This was before I pulled the carb and intake and cleaned it all up, but even then it functioned well even if it's better now:

https://www.youtube.com/watch?v=1937JuIHka4
 

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Tinkerer200

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My old computer does not do videos well so I don't fool with them. I suspect you have linkages wrong. I can send you a Service Manual for your engine IF you like. Address below,put in proper format and remind me engine model number and what you want. B&S says to always recheck the Static Governor setting whenever carb and or linkages have been, "messed with" (my words). You say you have adjusted that but did you do it correctly? You do not seem to fully know the correct method.

Walt Conner
wconner5 at frontier dot com
 

Patra

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The Governor springs and the arm itself are hooked up the exact same positions as they originally were, but again as I said it doesn't matter how I hook it up because it does the exact same thing regardless of how I set the governor rod, linkages, throttle cable, etc.

Sure, do you have a PDF link to the manual? I may already have it depending on what document it is.

I noticed one thing now. They still have a similar (older) model like mine sitting outside at a local Lowe's, and when I looked at the way things were hooked up, they were the same EXCEPT that the linkage on the right side of the carb had a thin spring wrapped around it, connecting somewhere up at the carb. I found this on the forum in another thread, and modified it to show the spring as it is on that model:

20170524_120406-adj.jpg

So I just hooked up a spring from the governor arm as shown to above where the carb is (I have no little hole in the swiveling part that comes out of the carb, so not sure how it would be hooked up -- or maybe it's a later model that has this only?) but had to put it on a bolt up there. This does hold the governor arm up a bit and I was able to run the engine with lower RPMs for the first time. But isn't the governor arm supposed to pull itself all the way up when the motor starts? That's what I don't understand, what that spring would even be good for.
 

bertsmobile1

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That is a damping spring it is designed to reduce the over run so the governor does not overshoot back off then pull on then back off in decreasing amounts till it smooths out
Loosen the clamp on the governor rod rotate the governor shaft as per the instructions in the manual then tighten the clamp bolt.

The governor MAKE THEN ENGINE GO SLOWER so when the engine is stopped and the throttle is wide open you should be ablt to put your finger on the governor arm and push the arm till the throttle closes fully onto the throttle stop ( idle adjustment screw ).
The rookie mistake is to assume the governor makes the engine go faster and adjust it backwards.

If after adjusting according to the manual the engine still races then the governor is broken.

So to recap
The throttle ( turtle & hare ) pulls the spring on the governor arm open
The governor pulls against that spring and tries to shut the throttle down
The faster the engine is going the harder the governor should pull against the spring.
From the video you posted yours is working backwards which is usually due to incorrect adjustment.
 

Patra

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Thanks for the information.

From the video you posted yours is working backwards which is usually due to incorrect adjustment.

What exactly in the video gives you the impression that it is working backwards?
 

Patra

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Update: Took the mower in to a local small engine repair shop. As I suspected, it was the internal governor gear that was busted. Turns out they first put a new gear in but it busted within 2 or 3 seconds, so they put another one in and the engine was running fine. However, once I got to mowing I starting seeing some smoke and I could smell oil. Turned it off, it was leaking oil. Took it back, after some assessment it appeared the crankshaft oil seal was leaking so they are replacing that now. Hopefully it will run well after this.
 
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