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Good morning all,

I'm Jonny, new to the forums and looking for help/advice on a project I'm struggling with.
I have a Husqvarna LT125 ride on mower sat in my garage with a Briggs and Stratton 10 or 12hp engine. The only problem I'm having now is making the throttle work. Engine and electrics are all good, but I simply cannot make the throttle cable and choke system work as its supposed to. The way it is now, is effectively running at maximum revs all the time with the throttle plate on the carburetor fully open.
I don't have the model type and code numbers at time of posting but I will add to the post when I can. There is no cutting deck as it will only be using for towing various things.

It was bought to replace an old one at my cricket club and ideally I would like it to be functional in the next few weeks as we start pre season ground work. I have another question about the other one which I will post separately.

Any information that can help would be much appreciated.

jaylees150 said:

Good morning all,

I'm Jonny, new to the forums and looking for help/advice on a project I'm struggling with.
I have a Husqvarna LT125 ride on mower sat in my garage with a Briggs and Stratton 10 or 12hp engine. The only problem I'm having now is making the throttle work. Engine and electrics are all good, but I simply cannot make the throttle cable and choke system work as its supposed to. The way it is now, is effectively running at maximum revs all the time with the throttle plate on the carburetor fully open.
I don't have the model type and code numbers at time of posting but I will add to the post when I can. There is no cutting deck as it will only be using for towing various things.

It was bought to replace an old one at my cricket club and ideally I would like it to be functional in the next few weeks as we start pre season ground work. I have another question about the other one which I will post separately.

Any information that can help would be much appreciated.

Click to expand...

Probably missing a spring or linkage. Will need to find model number for people to give you help. Looks like a Briggs single cylinder possibly starting with 28 on model number (6 digit number).

You are missing both the throttle and choke linkage. Once we get the model, type and code numbers, located on the shroud above the spark plug, we will be able to get you a service manual and part numbers.

His model is 281707-0200-01 with a starting date code of 900214##.

Attached are both a parts manual and service manual which should help you out.

Why not give him the correct IPL?

Because the linkages are the same and I found this one before you posted the model numbers. If the OP would stick to one thread it would be easier to help him and if you would see that there were two threads, you would understand the confusion.

Actually that how I got the engine numbers. But yes one thread is easier to follow. That's why on a forum I manage I combine the threads into one and link one to the other.

So, numbers on the front of this one as best as I can read with 2 digits I can't define
2-2707 015- 01 780417. I have a throttle linkage and spring which doesn't seem to reach the governor arm when the throttle plate is closed, I have no choke linkage. When I bought the mower the throttle cable was directly linked to the throttle plate on top of the carb but it wasn't working. I'm also not sure the governor spring is attached correctly.

I created two different threads because they are different problems on different engines. Neither are currently functional and I'm needing one or both running as soon as possible. I don't know if it makes a difference to parts availability but I'm located in the UK.

So let me get this straight, you created two threads about two engines, with different problems? Are the engines similar? On top of that you didn’t tell us this when you started the second thread. Now you are going to get everyone confused. Can you provide us a picture of the model numbers for the engine you are talking about in this thread. At this time I don’t know which engine you are talking about in this thread. Second, have you opened the manual I posted which contains pictures of how the linkages are attached?

They are both B&S and I think both 12HP but they have different parts.

The engine is this thread is shown in the first post with the red cover. The numbers I posted in the previous reply are on the front of the red cover but are incredibly difficult to make out even up close.

I have saved the manual, it's much appreciated and will definitely be useful.

Take one of your better half’s scrubbies and carefully rub over the engine numbers. Most times this will make the numbers pop out.

I'm all confused........

Jonny, you say you are new to help forums so I’ve got a couple of suggestions which will help you out. You’ve made some mistakes (posting two threads about different engines, but not clearly identifying what is going on) so I suggest you start over, and follow these steps in both threads.
1. Do not mix any info between threads, each is a separate problem.
2. Post all engine numbers for the engine in that thread.
3. Post your questions as clear as possible, only for that engine.
4. With this info we should be able to help you out.
5. Make sure that you only ask about 1 engine in each post.
Hopefully you will start over using these suggestions, or it is highly unlikely we can help you out.

The missing number after the first digit is either a 5 or 8. If it is a 10hp, it will be a 5, and 12hp an 8. You need to get the full 4-digit spec number, as "015" doesn't match anything. It should be four digits like this: 0167. Use a wire brush to get it as clean as possible, and you should be able to read it from one angle or another and either a flashlight or not. Need that number. You have the incorrect carburetor on there; it looks like an Amazon 20-dollar special. Do you have the original? You are missing the linkage rods going from the throttle control to the carb as well as the choke linkage. Do NOT allow that engine to run wide open; it will destroy the engine quickly. Also, can you provide the full model number and serial of the tractor? Since the LT125 was made from roughly 1990-2010, if you provide the full model, it will be easier to narrow down the correct engine. Your governor spring is hooked incorrectly, as is your throttle rod linkage; it belongs in the top hole of the governor shaft.

StarTech said:

His model is 281707-0200-01 with a starting date code of 900214##.

Click to expand...

How did you come up with that spec StarTech?

kbowley said:

How did you come up with that spec StarTech?

Click to expand...

It came from a picture on the other thread by this OP

A governor works by the internal parts a gear with flyweights attached the force a thimble against a lever. That lever is a part of the shaft that comes out of the carnkcase, it has the arm on that a spring is attached to it also has linkage as the attached picture shows. The spring on the rod in the picture is a slack take up spring and is used to take up slop in the linkage it is not really necessary.
The governor with the engine shut off should hold the carburetor wide open -- as the engine is started and comes up to speed it will if the internal governor is not broken and it is adjusted properly will slow the engine to the regulated speed -- if the arm is not restrained it will slow the engine to idle. On that externall arm is also a spring (the light blue one in your attachments). As I said the governor wants to slow the engine to be useful the engine needs more RPM to get it the spring pulls against the governor and once the forces become equal the engine maintains that speed.
The only adjustments are syncronizing the governor to the carburetor -- not hard but can be confusing -- and the top no load speed. After that unless there is damage or linkage is rubbing and hanging up on something all should be well.
Do not run engine "wide open" for long if you do you will get a window in the block and you will be able to see the internal parts!

If you have a throttle cable, the screw and clamp that holds the outside cable housing may have slipped. Disconnect the cable wire from the throttle plate lever and determine if the throttle wire is sliding easily in the housing when the throttel lever is moved. If not, the cable is rusted internally or broken. If so, replace the cable. If the cable is good, loosen the screw that holds the cable housing on the carb. Then attach the cable wire to the throttle plate lever and push the throttle lever wide open. with the throttle lever and throttle plate full open, secure the cable housing in place with the screw and clamp on the carb. Everything should work now. If reusing the old cable, oil the outside of the housing to lubricate the internal wire. If you throttle linkage instead of a cable, check the entire linkage for operation and lubricate as you go. Good Luck!!

I can send you a pic of the linkage installed correctly on 2/3/25. Sorry I don't know how to send online but can text the pic or possible part numbers that will work.

UPDATE

Having re visited this today in the daylight while I had some time, I have the throttle cable connected up and functioning properly. And I have the governor linkage and spring connected up as well. With the engine shut off I can manually push the throttle plate closed and it springs back nicely.

I re connected the battery and tried to start it with the throttle lever in the low revs position without success. As of right now I have nothing to connect the choke mechanism.

See if this helps. In your pictures the spring appears at an angle, it should be limp and in a straight line when in the idle position and pull on the governor arm as the throttle is opened. It also appears the bracket is not properly attached to the block, the top bolt is missing, this may be why the governor is not functioning properly.
When the engine starts you are saying the engine goes wide open? This could be that spring incorrectly hooked up or the governor is out of adjustment or not functioning. Unhook the spring and start the engine, it should immediately go to idle. Push on the governor arm and it should have a force trying to close the throttle. if not you have a governor issue -- out of adjustment or a failed governor.
A governor works by balancing the force of the flyweights against the spring -- the more the spring pulls the more the flyweights attempt to pull the throttle closed. That balance is the speed that you set the throttle at. The more you open the throttle the more pull is applied to the governor arm. The flyweight then attempt to close the throttle but can't due to the applied spring pull.
The second attachment is NOT a verticle governor and does not apply to your engine but it is the best diagram I could find to explain how a governor works.

jaylees150 said:

UPDATE

Having re visited this today in the daylight while I had some time, I have the throttle cable connected up and functioning properly. And I have the governor linkage and spring connected up as well. With the engine shut off I can manually push the throttle plate closed and it springs back nicely.

I re connected the battery and tried to start it with the throttle lever in the low revs position without success. As of right now I have nothing to connect the choke mechanism.

Click to expand...

Got to have some choke for cold starts.

bentrim said:

See if this helps. In your pictures the spring appears at an angle, it should be limp and in a straight line when in the idle position and pull on the governor arm as the throttle is opened. It also appears the bracket is not properly attached to the block, the top bolt is missing, this may be why the governor is not functioning properly.
When the engine starts you are saying the engine goes wide open? This could be that spring incorrectly hooked up or the governor is out of adjustment or not functioning. Unhook the spring and start the engine, it should immediately go to idle. Push on the governor arm and it should have a force trying to close the throttle. if not you have a governor issue -- out of adjustment or a failed governor.
A governor works by balancing the force of the flyweights against the spring -- the more the spring pulls the more the flyweights attempt to pull the throttle closed. That balance is the speed that you set the throttle at. The more you open the throttle the more pull is applied to the governor arm. The flyweight then attempt to close the throttle but can't due to the applied spring pull.
The second attachment is NOT a verticle governor and does not apply to your engine but it is the best diagram I could find to explain how a governor works.

Click to expand...

It's starting to look a lot better I think! I know that since I bought it it's never had the top bolt for that throttle plate, It doesnt appear to line up with the governor arm connected. I'm wondering if the governor arm should be to the left of the plate?
I can't seem to find many examples of this particular set up online to copy from.

kbowley said:

The missing number after the first digit is either a 5 or 8. If it is a 10hp, it will be a 5, and 12hp an 8. You need to get the full 4-digit spec number, as "015" doesn't match anything. It should be four digits like this: 0167. Use a wire brush to get it as clean as possible, and you should be able to read it from one angle or another and either a flashlight or not. Need that number. You have the incorrect carburetor on there; it looks like an Amazon 20-dollar special. Do you have the original? You are missing the linkage rods going from the throttle control to the carb as well as the choke linkage. Do NOT allow that engine to run wide open; it will destroy the engine quickly. Also, can you provide the full model number and serial of the tractor? Since the LT125 was made from roughly 1990-2010, if you provide the full model, it will be easier to narrow down the correct engine. Your governor spring is hooked incorrectly, as is your throttle rod linkage; it belongs in the top hole of the governor shaft.

Click to expand...

This is the sticker that came from the rear of the mower. And after a significant amount of scrubbing and cleaning, I have determined that the engine model number is 252707 0151-01 780417.

jaylees150 said:

UPDATE

Having re visited this today in the daylight while I had some time, I have the throttle cable connected up and functioning properly. And I have the governor linkage and spring connected up as well. With the engine shut off I can manually push the throttle plate closed and it springs back nicely.

I re connected the battery and tried to start it with the throttle lever in the low revs position without success. As of right now I have nothing to connect the choke mechanism.

Click to expand...

Is your fuel filter on backwards? Look for an arrow on the body.

slomo said:

Is your fuel filter on backwards? Look for an arrow on the body.

Click to expand...

Makes no difference; they have no check valve, and gas can flow either way.

This is an older engine, I would guess around the early 80's or older.
The model a type numbers are stamped in the top cover (flywheel shroud). Usually on the very back above the head, or on one side.

Let's resolve one post, call it fixed then move on to the second one. Get rid of the confusion.
At first glance, it has a wrong carburetor that someone put on it.