B&S 10/12HP throttle repair

[jaylees150]

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.

 

[Rivets]

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

 

[slomo]

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

 

[Rivets]

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.

 

[kbowley]

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.

 

[kbowley]

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

How did you come up with that spec StarTech?

 

[ILENGINE]

How did you come up with that spec StarTech?

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

https://www.lawnmowerforum.com/threads/b-s-12hp-fuel-delivery-issue.78791/

 

[bentrim]

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!

 

[rhkraft]

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!!

 

[outdoorpowermike]

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.