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My decades old L120 (always reliable until this year) has had a fit getting back to normal this year. Replaced starter, fuel lines, fuel pump, clutch, plugs, air filter, one of the spindles and all -- but had removed carb and cleaned it out and in replacing that carb think I've incorrectly attached the throttle cable to the governor adjuster or whatever the bracket down below the carburetor is called. And, to mention this quirk, before I got the mower someone replaced whatever engine it originally had with a Briggs & Stratton Model 350777-1034-A1 (Code 97061711) which bears labels indicating the engine is a 19.5 I/C Platinum Craftsman engine (which is why I believe the engine was replaced -- otherwise why would my Deere have a Craftsman labeled engine, right?).

So, by the way, I believe the carburetor on that engine is an 847395 B&S unit. Whatever. It was running rich. I thought I'd watch Youtube videos and saw Tarryl's video about the little nozzle gasket with four holes at top being clogged up -- but my carburetor is a single barrel and the 841649 part I got was a wasted $6.00 purchase. Fine. However, in investigating the matter (and considering why the engine would run rich) I noted that the choke plate wasn't fully opened up when choke lever pulled back -- so I adjusted that and the engine ran brilliantly -- but at full throttle only and adjusting the throttle lever does nothing about that. Which almost brings me to my question -- after investigating governor adjustments and looking at the whatever that bracket is with springs and stuff with the round plate on front (below the carburetor) I realized that I had probably connected the throttle cable to the wrong hole on that round plate because when I adjusted the throttle lever to low speed it was shoving that plate into wide open throttle. There was a different (lower) hole on that plate so I re-located the throttle cable to that hole and thought that would fix it. Nope. Still running at wide open throttle -- it'll mow and all -- but only without the air filter -- a brand new clean one.

So, my question: Is anyone familiar with the engine model noted above and its governor/throttle linkages? If so, if you could give a bit of advice on how to regain throttle control over the speed of the engine, I would be most appreciative. It could be a missing spring allowing the governor to be wide open. I'm going to see if the governor needs adjustment and get into the operating works of that throttle/governor bracket and see if I can figure out what needs fixing but thought I'd ask for insight and advice if anyone can provide same.

Thanks for your assistance. I'm not really much of a small engine guy -- but will add that I've checked valve clearances and the guides haven't dislocated so that isn't a factor involved (just to note).

:welcome:

Welcome to the forum! I'm going to move your thread over to our John Deere section to see if anyone over there is familiar with it.

You will find step by step instructions for cleaning various carbs here http://outdoorpowerinfo.com/
You lost me totally with your descriptions so a couple of photos would be really beneficial , by preference without the air filter housing so we can see the linkages.
And if possible ut the camera on some thing so the photos are full frame and in clear sharp focus.

Thanks. I'll take some photos as I take a look at it this afternoon.

Was raining last weekend and I didn't get to take pictures -- but here they are. Four pictures: One of the engine configuration with air filter on (0415). Picture 0416 with front air breather removed (and I probably should have taken one of the one barrel carburetor but didn't. Pictures 0417 and 0418 with full throttle and low throttle captions. Still running at full throttle. I took the throttle cable off and rotated the plate manually and still no difference -- engine runs at full throttle and cannot be adjusted or will not adjust. Just runs wide open. Help! And thanks.

OK,
Firstly are you sure that the cable comes in from the right side ?
The photo looks like there is a wear mark on the left side cable clamp.
Next the engine is controlled by the governor, the throttle cable sets the upper limit that the governor can open the throttle to.
The lever in the background to the left is the governor and that lever should be connected to the throttle control by a spring so that the spring is pulling the carb butterfly closed

Yes, throttle cable comes in from the right side and the spring to throttle butterfly is attached, it is (however) pulling the throttle butterfly fully open at all times. But, like I said, even with the throttle cable removed rotation of the plate makes no difference -- throttle butterfly is in wide open position. I'll take pictures of the carb itself and send later. Thanks for your reply.

bertsmobile1 said:

OK,
Firstly are you sure that the cable comes in from the right side ?
The photo looks like there is a wear mark on the left side cable clamp.
Next the engine is controlled by the governor, the throttle cable sets the upper limit that the governor can open the throttle to.
The lever in the background to the left is the governor and that lever should be connected to the throttle control by a spring so that the spring is pulling the carb butterfly closed

Click to expand...

The throttle should always be open fully when the engine is turned off regardless of what position the throttle lever is in because the governor spring is stronger than the throttle spring.
When you move the throttle control, the wire turns that plate.
The plate stretches a spring between it and the GOVERNOR ARM the governor arm should be the only thing connected to the throttle butterfly and that has to be a solid rod.
The spring pulls the governor shaft into the open position.
The engine rotating mover the governor into the closed position.
When the engine is stationary the governor holds the throttle wide open
As soon as the engine starts to turn the governor closes the throttle down to whatever position you have set the throttle control to.

Put your finger on the governor lever, you should be able to move it by hand to fully close the throttle butterfly.

And remember the throttle butterfly is the one that you can not see at the back of the carb nearest the engine.
The butterfly at the front is the choke.

People not familiar with these engines get them confused and on some engines you can transpose the control cables

deerel120 said:

Was raining last weekend and I didn't get to take pictures -- but here they are. Four pictures: One of the engine configuration with air filter on (0415). Picture 0416 with front air breather removed (and I probably should have taken one of the one barrel carburetor but didn't. Pictures 0417 and 0418 with full throttle and low throttle captions. Still running at full throttle. I took the throttle cable off and rotated the plate manually and still no difference -- engine runs at full throttle and cannot be adjusted or will not adjust. Just runs wide open. Help! And thanks.

Click to expand...

The trottle cable should be conected in the bottom hole on the throttle disk, not in the top hole.

http://outdoorpowerinfo.com/repairs/briggs_intek_v-twin_carb.asp

bertsmobile1 said:

The throttle should always be open fully when the engine is turned off regardless of what position the throttle lever is in because the governor spring is stronger than the throttle spring.
When you move the throttle control, the wire turns that plate.
The plate stretches a spring between it and the GOVERNOR ARM the governor arm should be the only thing connected to the throttle butterfly and that has to be a solid rod.
The spring pulls the governor shaft into the open position.
The engine rotating mover the governor into the closed position.
When the engine is stationary the governor holds the throttle wide open
As soon as the engine starts to turn the governor closes the throttle down to whatever position you have set the throttle control to.

Put your finger on the governor lever, you should be able to move it by hand to fully close the throttle butterfly.

And remember the throttle butterfly is the one that you can not see at the back of the carb nearest the engine.
The butterfly at the front is the choke.

People not familiar with these engines get them confused and on some engines you can transpose the control cables

Click to expand...

Great information -- I've never been schooled on the functional mechanics of how the governor operates. Really appreciate the insight. Will advise what I'm able to do with it. Thanks.

bertsmobile1 said:

The throttle should always be open fully when the engine is turned off regardless of what position the throttle lever is in because the governor spring is stronger than the throttle spring.
When you move the throttle control, the wire turns that plate.
The plate stretches a spring between it and the GOVERNOR ARM the governor arm should be the only thing connected to the throttle butterfly and that has to be a solid rod.
The spring pulls the governor shaft into the open position.
The engine rotating mover the governor into the closed position.
When the engine is stationary the governor holds the throttle wide open
As soon as the engine starts to turn the governor closes the throttle down to whatever position you have set the throttle control to.

Put your finger on the governor lever, you should be able to move it by hand to fully close the throttle butterfly.

And remember the throttle butterfly is the one that you can not see at the back of the carb nearest the engine.
The butterfly at the front is the choke.

People not familiar with these engines get them confused and on some engines you can transpose the control cables

Click to expand...

Bertsmobile:
With the insight from your message (above) and watching a couple of Youtube videos on governor adjustment, I finally figured out the problem. The shaft to which the governor arm on my machine is attached needs to be turned counterclockwise on my vtwin. Seems like every other machine in any video I watched is set when rotated clockwise. I finally was able to put the puzzle together when I saw a video with someone in the crankcase demonstrating how the governor actually works and then I understood that mine had probably needed to be adjusted forever because I never really did have much throttle control. And now I do.

What tipped me off was the fact that rotating the swivel plate wasn't doing anything to slow down the engine and there wasn't any play when I -- as you said above -- "put your finger on the governor lever, you should be able to move it by hand to fully close the throttle butterfly." Another Youtube video demonstrated the operation of the swivel plate and showed that when the throttle cable moves the plate to throttle-up the machine it stretches the spring between the swivel plate and the governor arm -- but the way mine was adjusted the spring had no tension at what I thought was wide open throttle -- so I figured things were backwards; it all worked when I made the governor adjustment you would make for a governor shaft that is rotated counterclockwise to set.

I'm still not out of the woods, though, because when I put the new air filter on it (brand new air filter) it started running rich and bogging down. Took the air filter off and the engine worked like a dream. Not quite sure why that is, It wasn't dusty today so I went ahead and mowed. Had to. But any thoughts about why putting the air filter on would make it start running rich?

Thanks for your help.

Congratulations,
I hope you have gained some satisfaction from finally nutting out a problem you seem to have inherited.

I cop a bit of grief for the lengths of my posts but I have always believed in the teach a man to fish philosophy.
Once people understand how things are supposed to work , most can nut it out, mowers are not rocket science.

To burn properly you need a specific ratio of air to fuel.
Air filters reduce the air flow so if you are running rich with the filter on and running clean with the filter off, that says you are getting too much fuel.
The engine breather can also cause similar symptoms so the first test is to disconnect the tube that goes from the engine to the carb don't pinch it off, just pull it off the carb end.
If that makes no difference then the main jet is too big , missing or not seated properly.
or the level of the fuel in the float bowl is too high.