bolens st140 not starting

bolensst140

Member
Joined
Dec 21, 2023
Threads
6
Messages
20
it used to turn over i put gas in it and new fuel line now it wont even turn over it also hasn't actually ran in like 10 years
 

Bertrrr

Well-Known Member
Joined
Mar 11, 2021
Threads
5
Messages
421
How long since it turned over ?
Check battery voltage first - at the battery terminals , if 12 volts there , look at the solenoid terminal , should have 12 volts on one side even without the key turned on, if voltage present there , turn key to Start and listen for any clicking noise at the solenoid and post results , pull your plug and see if it rolls over by hand or with the starter as well.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,769
If my research is correct your engine should be a Briggs 400707-1205-02. As stated you are going to have to do some electrical troubleshooting to solve your problem. Start with the battery and it has not been replaced in 10 years probably needs to be replaced. When you have a good battery installed follow this procedure to find the cause of your problem.

Electrical problems can be very easy or very difficult, depending on four things.

1. How well you understand basic electricity.
2. What tools you have and know how to use.
3. How well you follow directions.
4. You don't overlook or assume anything and verify everything.

Remember we cannot see what you are doing. You are our eyes, ears and fingers in solving this problem. You must be as accurate as you can when you report back. The two basic tools we will ask you to use are a test light and a multi-meter. If you have an assistant when going through these tests it would be very helpful. These steps work the best when done in order, so please don't jump around. Now let's solve this problem.

First, check the fuse(s), check battery connections for corrosion (clean if necessary) and voltage - above 12.5 volts should be good. Check and make sure the chassis ground is clean and tight.
Second, check for power from the battery to one of the large terminals on the solenoid. One of the wires is connected directly to the battery and has power all the time so one of the large terminals should light a test light or show 12 volts on a meter at all times.
Third, check for power at the small terminal of the solenoid while depressing the clutch/brake pedal and holding the key in the start position (you may need an assistant to sit in the seat to override the safety switch). If your solenoid is a four wire solenoid, check both small wire terminals as one is ground and the other is power from the ignition switch. If your solenoid is a three wire solenoid, make sure the solenoid body is not corroded where it bolts to the chassis of the mower as this is your ground path back to the battery. If in doubt, remove the solenoid and clean the mounting area down to bare metal. If there is no power to the small terminal then your problem is most likely a safety switch, ignition switch or in the wiring.
Fourth, check for power on the other large terminal of the solenoid while holding the key in the start position (you may need an assistant to sit in the seat to override the safety switch).
Fifth, check for power at the starter while holding the key in the start position (assistant again).
Sixth, check your ground circuit back to the battery.
After you have gone through each of the above steps, let us know what happened when you did each step. At that point we will have great info to tell you how to proceed. Remember you are our eyes, ears, and fingers, so please be as accurate as possible.

Be as specific as possible with voltage readings as this will help diagnose your problem quicker. If you do not know how to perform the above checks, just ask and I will try to guide you through it. Youtube also has some videos and as you know a picture is worth a thousand words.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
79
Messages
10,274
Rivets the engine really depends on the year and even some models had a single, opposed, or Vanguard engine. Either way it should be a 14hp engine; although, there is 12hp and a 18hp version. The OP need to post the engine info.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,769
Star, I said if my research is correct. ST140 crosses to a 3114G, which uses a 14hp engine. I used that model to get the engine number I posted. I’ve worked on many of these units, as they were very popular around here. Not my first rodeo, but I might still be wrong. Won’t be the first time you’ve tried to shoot me down.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
79
Messages
10,274

bolensst140

Member
Joined
Dec 21, 2023
Threads
6
Messages
20
Rivets the engine really depends on the year and even some models had a single, opposed, or Vanguard engine. Either way it should be a 14hp engine; although, there is 12hp and a 18hp version. The OP need to post the engine info.
mines the 14 horse
 

bolensst140

Member
Joined
Dec 21, 2023
Threads
6
Messages
20
i have found out the starter is junk cause I left it outside this is my first totally a project lawn mower and im still learning thanks for all the help guys ill probably be making more posts about it but i think i have resolved my issue.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
79
Messages
10,274
Now it would actually help a lot if the OP would go out and get, the model, type code, and date code off the engine and post it. There is a 14hp single cylinder, 14 hp opposed, and a 14 hp v-twin that could have been used.
 
Last edited:

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,769
Stop wasting my time trying to prove you’re the best tech on this forum. You may know a lot, but as I’ve said before your people skills are lacking. Just the grinch who’s tried to tolerate you, but your attitude toward anyone who doesn’t bow to your knowledge is an inferior.
 
Top