B&S Won't Start
#1
10-13-04, 12:47 PM
B&S Won't Start
"I have a late 80's B&S 12HP engine on a electric start Simplicity
riding mower. As I mowed through some heavy grass and small brush the
engine slowed down and almost died out. Then it got back up to speed
after I got out of this area. I mowed through the same area again and
the engine slowed down and stopped. Next the engine won't start. The
starter engages flywheel but the flywheel only moves appx. 1/8'' each
time. Also, I can't move the flywheel by hand. Any ideas?
Thanks
riding mower. As I mowed through some heavy grass and small brush the
engine slowed down and almost died out. Then it got back up to speed
after I got out of this area. I mowed through the same area again and
the engine slowed down and stopped. Next the engine won't start. The
starter engages flywheel but the flywheel only moves appx. 1/8'' each
time. Also, I can't move the flywheel by hand. Any ideas?
Thanks
#2
10-13-04, 05:08 PM
Did you check your oil? Its probally very low or non existant. If you still have the proper amount of oil in the engine, then it should still spin freely. If the motor is cooled down and can't spin it and neither can you, then either the engine is shot, or the battery needs to be charged or replaced. Let me know on what you find out. As for the mower slowing down it isn't abnormal for that to happen espically on long grass, and when the grass is wet. You might also need the carburetor cleaned out considering the age and if it has ever been cleaned out.
Kushballz
Kushballz
#4
10-14-04, 09:15 AM
Change your oil now, drain the old oil and just for cuz, run a magnet through it and check it for metal particles. It doesnt sound like you should find any but good to check in this case. Refill with new oil!!
Next remove the spark plug. Using the pulley on the bottom of the engine, see if you can turn the engine by hand CLockwise (normal direction) If you can not turn it by hand, use a strap wrench or pipe wrench will work too.
This is a "resurection" so be GENTLE but deliberate!
You can put the wrench on the shaft between the main drive pulley and the deck pulley, turn the engine slowly and only in one direction. Once you have got the engine to turn a bit, put some lube in the cylinder via the spark plug hole. A tablespoon of oil or some spray lube, if choice of WD-40 or oil, use a bit of oil. Continue to turn the engine checking occasionally to see if you can turn by hand. Use the pulley and not the screen on top of the flywheel to turn it.
Again be gentle and STOP if any solid resistance is felt.
Once you have the engine turning by hand, (turn it several times and add another spoon of oil b4 the next step).
With the spark plug still removed, try to spin the engine with the starter now.
If it will spin with the plug out freely with the starter, put the plug in and try to start it. If it starts,(its gonna smoke, dont worry its all that luv lube you have been feeding it and should cease or lessen in a few minutes) let it run a few minutes, change throttle speed a few times from idle to full. After a few minutes shut it off and CHECK THE OIL!! Restart it and lightly try putting it under load by engaging the drive first then the blades IN MOWED OR LIGHT GRASS. If you made it this far you should be good to go. Keep a very close eye on the oil to see if it is using it, or if it still smokes heavily you may have overhaul or replacement in the future.
If with the plug in it still wont spin, you can try jumping it with a car battery for some extra amps.
Do not sit there with the key to start and the engine not turning, if its not already, you will burn the starter up. If the engine and starter still drag or will not spin when jumping with a car battery or on its own, you can try some more lube and turning by hand.
If all this fails and you can not get the starter to turn the engine, 2 things, either your starter has gone south (have it checked at a shop) or your engine may be shot.
Must be due to end of the mowing season but I have had 3 mowers in the last week with the same problem
Happy to report however, that all are back home and in service now 
Good Luck and keep us posted.
Next remove the spark plug. Using the pulley on the bottom of the engine, see if you can turn the engine by hand CLockwise (normal direction) If you can not turn it by hand, use a strap wrench or pipe wrench will work too.
This is a "resurection" so be GENTLE but deliberate!
You can put the wrench on the shaft between the main drive pulley and the deck pulley, turn the engine slowly and only in one direction. Once you have got the engine to turn a bit, put some lube in the cylinder via the spark plug hole. A tablespoon of oil or some spray lube, if choice of WD-40 or oil, use a bit of oil. Continue to turn the engine checking occasionally to see if you can turn by hand. Use the pulley and not the screen on top of the flywheel to turn it.
Again be gentle and STOP if any solid resistance is felt.
Once you have the engine turning by hand, (turn it several times and add another spoon of oil b4 the next step).
With the spark plug still removed, try to spin the engine with the starter now.
If it will spin with the plug out freely with the starter, put the plug in and try to start it. If it starts,(its gonna smoke, dont worry its all that luv lube you have been feeding it and should cease or lessen in a few minutes) let it run a few minutes, change throttle speed a few times from idle to full. After a few minutes shut it off and CHECK THE OIL!! Restart it and lightly try putting it under load by engaging the drive first then the blades IN MOWED OR LIGHT GRASS. If you made it this far you should be good to go. Keep a very close eye on the oil to see if it is using it, or if it still smokes heavily you may have overhaul or replacement in the future.
If with the plug in it still wont spin, you can try jumping it with a car battery for some extra amps.
Do not sit there with the key to start and the engine not turning, if its not already, you will burn the starter up. If the engine and starter still drag or will not spin when jumping with a car battery or on its own, you can try some more lube and turning by hand.
If all this fails and you can not get the starter to turn the engine, 2 things, either your starter has gone south (have it checked at a shop) or your engine may be shot.
Must be due to end of the mowing season but I have had 3 mowers in the last week with the same problem
Happy to report however, that all are back home and in service now 
Good Luck and keep us posted.
Last edited by Azis; 10-14-04 at 09:25 AM.
#5
11-01-04, 05:56 AM
I have changed the oil and have gotten the engine to spin. First I spun the pully with a pipe wrench and now I can spin by hand. Without spark plug it spins freely with the starter. With the plug in however, it spins freely for almost one revolution then it spins slowly until it to the free spinning portion of the revolution. I have tried with car battery for extra amps but the same thing happens. I am getting spark, and I've tried starter fluid in the carb. Any ideas?
#6
11-01-04, 10:47 AM
The car battery your using, is it in a running car when your jumping it?
You could try to put a bit of oil in the plug hole and spin the engine by hand a few times to help lube the cylinder.
You may be at the point where you will need to at least pull the head to see what condition the inards are in.
You could try to put a bit of oil in the plug hole and spin the engine by hand a few times to help lube the cylinder.
You may be at the point where you will need to at least pull the head to see what condition the inards are in.
