I cut the grass and then changed the oil and filter. Now mower won't start. I replaced spark plug but still won't start. I checked the fuel filter and it flows. Cleaned air filter. I sprayed with starting fluid and it runs for a few seconds and dies. Any suggestions?
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B&S 18HP engine won't start
- Thread starter Jerryb
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You may have filled the carb with oil through the breather system. Did you tip the mower over to drain the oil?
Check carb bowl maybe garbage in there. Also check float to see if working proper.
Also do you have fuel shut off valve. That could also be a problem.
Thanks for your help. I took the carb apart and cleaned it but it looked clean already. The engine now starts, but when I lift my foot off the clutch, the engine stops. Also if I try to engage the blades, it stops. It will only run if I keep my foot on the clutch. There is some connection between the clutch and the carberator that I am missing. I need to read the operator's manual but there is not a lot of detail. Any suggestions?
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Make sure the choke flap in the Carb moves freely and is properly connected. On the Intek engines, I've seen a little grit get down into the hole that this flap rotates in and mess up the works completely. Blasting it with brake cleaner or removing it and cleaning the hole and sanding the post have had good results.
Originally Posted By: Jerryb
Thanks for your help. I took the carb apart and cleaned it but it looked clean already. The engine now starts, but when I lift my foot off the clutch, the engine stops. Also if I try to engage the blades, it stops. It will only run if I keep my foot on the clutch. There is some connection between the clutch and the carberator that I am missing. I need to read the operator's manual but there is not a lot of detail. Any suggestions?
Sounds like an electrical thing. If engines is running fine and it kicks out clean it sounds like no current is going to the spark plug. Coil or some contact switch.
Thanks for your help. I took the carb apart and cleaned it but it looked clean already. The engine now starts, but when I lift my foot off the clutch, the engine stops. Also if I try to engage the blades, it stops. It will only run if I keep my foot on the clutch. There is some connection between the clutch and the carberator that I am missing. I need to read the operator's manual but there is not a lot of detail. Any suggestions?
Sounds like an electrical thing. If engines is running fine and it kicks out clean it sounds like no current is going to the spark plug. Coil or some contact switch.
If the engine starts fairly easily and runs more than one or two turns over (which as I interpret the OP, it does), then the spark plug is getting fire and the timing is on. The way I see it, when load is applied the throttle opens but the mixture is too rich due to a choke that stuck in the closed position, therefore the engine dies.
To the OP - when the engine is running at idle, try to manually manipulate the choke and see if you're able to get more out of it.
To the OP - when the engine is running at idle, try to manually manipulate the choke and see if you're able to get more out of it.
Thanks again. I think you are all close to the answer.
When I have my foot on the clutch/brake, the engine starts and runs fine. When I take my foot off the clutch, I can see a rod on top of the carb pull back and it looks like it is closing the butterfly plate that controls fuel from the carb to the piston. When I slowly move my foot, I can push back on the clutch to prevent the engine from stopping. I don;t know what causes the clutch pedal to effect the carb. Governor problem?
Also, when I try to engage the blades, the engine stops. If I play with the blade engage handle, I can release it so the engine will keep runing. This looks like an electrical switch problem. I looked at the electrical sonnections and they seem to be OK. The manual doesn't address these problems. Can anyone recommend a book or site I can look at? I appreciate you guys trying to help without seeing the mower.
Thanks
When I have my foot on the clutch/brake, the engine starts and runs fine. When I take my foot off the clutch, I can see a rod on top of the carb pull back and it looks like it is closing the butterfly plate that controls fuel from the carb to the piston. When I slowly move my foot, I can push back on the clutch to prevent the engine from stopping. I don;t know what causes the clutch pedal to effect the carb. Governor problem?
Also, when I try to engage the blades, the engine stops. If I play with the blade engage handle, I can release it so the engine will keep runing. This looks like an electrical switch problem. I looked at the electrical sonnections and they seem to be OK. The manual doesn't address these problems. Can anyone recommend a book or site I can look at? I appreciate you guys trying to help without seeing the mower.
Thanks
The only thing I can think of might be to download the manual from the OEM website.
You can try the Lawnsite forum.
Thank you for all your help. I went to the Sears site and others had the same problem. It seems to be the seat safety switch that cuts off the mower if no one is in the seat. There is also a switch that prevents you from starting the mower with the blades engaged. I took of the seat safety and checked it with an ohm meter. It seems ok but I sprayed it with WD40. I also sprayed the blade safety switch. I was able to cut the grass today.
Now my son called and said his car overheats in 15 minutes. I told him to check the thermostat. He's 45 miles away so there is not much I can do frome here except give advice.
Thanks for all your help.
Now my son called and said his car overheats in 15 minutes. I told him to check the thermostat. He's 45 miles away so there is not much I can do frome here except give advice.
Thanks for all your help.
Might be the water pump, that happened once in my dodge stratus.
P.S. Good to hear the mower is working.
P.S. Good to hear the mower is working.
Originally Posted By: Jerryb
Thanks for your help. I took the carb apart and cleaned it but it looked clean already. The engine now starts, but when I lift my foot off the clutch, the engine stops. Also if I try to engage the blades, it stops. It will only run if I keep my foot on the clutch. There is some connection between the clutch and the carberator that I am missing. I need to read the operator's manual but there is not a lot of detail. Any suggestions?
IF you actually said WHAT mower/tractor this is, there may be a schematic available.
Usually, if the engine dies (electrically) when lifting the clutch pedal, the seat switch is bad or mis adjusted.
Thanks for your help. I took the carb apart and cleaned it but it looked clean already. The engine now starts, but when I lift my foot off the clutch, the engine stops. Also if I try to engage the blades, it stops. It will only run if I keep my foot on the clutch. There is some connection between the clutch and the carberator that I am missing. I need to read the operator's manual but there is not a lot of detail. Any suggestions?
IF you actually said WHAT mower/tractor this is, there may be a schematic available.
Usually, if the engine dies (electrically) when lifting the clutch pedal, the seat switch is bad or mis adjusted.
Originally Posted By: Bill Kapaun
Originally Posted By: Jerryb
Thanks for your help. I took the carb apart and cleaned it but it looked clean already. The engine now starts, but when I lift my foot off the clutch, the engine stops. Also if I try to engage the blades, it stops. It will only run if I keep my foot on the clutch. There is some connection between the clutch and the carberator that I am missing. I need to read the operator's manual but there is not a lot of detail. Any suggestions?
IF you actually said WHAT mower/tractor this is, there may be a schematic available.
Usually, if the engine dies (electrically) when lifting the clutch pedal, the seat switch is bad or mis adjusted.
The brake clutch peddle has nothing to do with the seat switch solenoid? The engine will not start unless the hand brake is engaged, once the hand brake is disengaged when engine is started if one leaves off the seat the engine will shutdown. This is a safety feature if an operator falls off his mower with no operator to prevent ... a safety feature.
Originally Posted By: Jerryb
Thanks for your help. I took the carb apart and cleaned it but it looked clean already. The engine now starts, but when I lift my foot off the clutch, the engine stops. Also if I try to engage the blades, it stops. It will only run if I keep my foot on the clutch. There is some connection between the clutch and the carberator that I am missing. I need to read the operator's manual but there is not a lot of detail. Any suggestions?
IF you actually said WHAT mower/tractor this is, there may be a schematic available.
Usually, if the engine dies (electrically) when lifting the clutch pedal, the seat switch is bad or mis adjusted.
The brake clutch peddle has nothing to do with the seat switch solenoid? The engine will not start unless the hand brake is engaged, once the hand brake is disengaged when engine is started if one leaves off the seat the engine will shutdown. This is a safety feature if an operator falls off his mower with no operator to prevent ... a safety feature.
Originally Posted By: Mamala Bay
The brake clutch peddle has nothing to do with the seat switch solenoid? The engine will not start unless the hand brake is engaged, once the hand brake is disengaged when engine is started if one leaves off the seat the engine will shutdown. This is a safety feature if an operator falls off his mower with no operator to prevent ... a safety feature.
Your ignorance is profound!
Typically-
The brake/clutch switch has 2 parts.
When the pedal is depressed, it completes the circuit to the starter solenoid.
It ALSO opens the engine kill switch circuit!
Once the pedal is raised, it disengages the start circuit and completes the engine kill circuit.
The engine kill circuit then goes to the PTO switch.
When the PTO is OFF, the engine kill circuit is open. PTO ON and the kill circuit is connected and then goes to the seat switch
The seat switch is open when someone is in the seat, so the kill wire is not grounded.
That said, the OP mentioned it's a Sears tractor. Sears tractors have AT LEAST a dozen different schematics and not all follow the above described "typical" engine kill circuit.
Some systems have up to 3 Operator Presence Relays. Most have 0.
Those with 1 or more OPR's are "typically wired very different regarding the seat switch, where the seat switch must be closed to provide 12V to an OPR to "onground" the kill circuit.
IF the OP would post the Sears 917.xxxxxx number, the correct schematic is probably available!
That would save a LOT of time!!!
The brake clutch peddle has nothing to do with the seat switch solenoid? The engine will not start unless the hand brake is engaged, once the hand brake is disengaged when engine is started if one leaves off the seat the engine will shutdown. This is a safety feature if an operator falls off his mower with no operator to prevent ... a safety feature.
Your ignorance is profound!
Typically-
The brake/clutch switch has 2 parts.
When the pedal is depressed, it completes the circuit to the starter solenoid.
It ALSO opens the engine kill switch circuit!
Once the pedal is raised, it disengages the start circuit and completes the engine kill circuit.
The engine kill circuit then goes to the PTO switch.
When the PTO is OFF, the engine kill circuit is open. PTO ON and the kill circuit is connected and then goes to the seat switch
The seat switch is open when someone is in the seat, so the kill wire is not grounded.
That said, the OP mentioned it's a Sears tractor. Sears tractors have AT LEAST a dozen different schematics and not all follow the above described "typical" engine kill circuit.
Some systems have up to 3 Operator Presence Relays. Most have 0.
Those with 1 or more OPR's are "typically wired very different regarding the seat switch, where the seat switch must be closed to provide 12V to an OPR to "onground" the kill circuit.
IF the OP would post the Sears 917.xxxxxx number, the correct schematic is probably available!
That would save a LOT of time!!!
Originally Posted By: Bill Kapaun
Originally Posted By: Mamala Bay
The brake clutch peddle has nothing to do with the seat switch solenoid? The engine will not start unless the hand brake is engaged, once the hand brake is disengaged when engine is started if one leaves off the seat the engine will shutdown. This is a safety feature if an operator falls off his mower with no operator to prevent ... a safety feature.
Your ignorance is profound!
Typically-
The brake/clutch switch has 2 parts.
When the pedal is depressed, it completes the circuit to the starter solenoid.
It ALSO opens the engine kill switch circuit!
Once the pedal is raised, it disengages the start circuit and completes the engine kill circuit.
The engine kill circuit then goes to the PTO switch.
When the PTO is OFF, the engine kill circuit is open. PTO ON and the kill circuit is connected and then goes to the seat switch
The seat switch is open when someone is in the seat, so the kill wire is not grounded.
That said, the OP mentioned it's a Sears tractor. Sears tractors have AT LEAST a dozen different schematics and not all follow the above described "typical" engine kill circuit.
Some systems have up to 3 Operator Presence Relays. Most have 0.
Those with 1 or more OPR's are "typically wired very different regarding the seat switch, where the seat switch must be closed to provide 12V to an OPR to "onground" the kill circuit.
IF the OP would post the Sears 917.xxxxxx number, the correct schematic is probably available!
That would save a LOT of time!!!
Well in a clutch/brake system one must make a complete stop and depress the clutch/brake to change into gears. Would depressing the brake to stop and change gears send a current to the starter when engine is running?
Originally Posted By: Mamala Bay
The brake clutch peddle has nothing to do with the seat switch solenoid? The engine will not start unless the hand brake is engaged, once the hand brake is disengaged when engine is started if one leaves off the seat the engine will shutdown. This is a safety feature if an operator falls off his mower with no operator to prevent ... a safety feature.
Your ignorance is profound!
Typically-
The brake/clutch switch has 2 parts.
When the pedal is depressed, it completes the circuit to the starter solenoid.
It ALSO opens the engine kill switch circuit!
Once the pedal is raised, it disengages the start circuit and completes the engine kill circuit.
The engine kill circuit then goes to the PTO switch.
When the PTO is OFF, the engine kill circuit is open. PTO ON and the kill circuit is connected and then goes to the seat switch
The seat switch is open when someone is in the seat, so the kill wire is not grounded.
That said, the OP mentioned it's a Sears tractor. Sears tractors have AT LEAST a dozen different schematics and not all follow the above described "typical" engine kill circuit.
Some systems have up to 3 Operator Presence Relays. Most have 0.
Those with 1 or more OPR's are "typically wired very different regarding the seat switch, where the seat switch must be closed to provide 12V to an OPR to "onground" the kill circuit.
IF the OP would post the Sears 917.xxxxxx number, the correct schematic is probably available!
That would save a LOT of time!!!
Well in a clutch/brake system one must make a complete stop and depress the clutch/brake to change into gears. Would depressing the brake to stop and change gears send a current to the starter when engine is running?
Quote:
Well in a clutch/brake system one must make a complete stop and depress the clutch/brake to change into gears.
I've driven a few and never had to come to a 'complete stop' to change gears. You just release the clutch and shift while using the momentum to carry you forward, then let up on the clutch. There's no need to come to a stop at all. Ever try coming to a complete stop then shifting your mower into fifth and letting off the clutch?
The starter's circuit can only be closed when the mower has the clutch/brake depressed, however whether or not the circuit is fully closed and current reaches the starter is governed by key position.
Well in a clutch/brake system one must make a complete stop and depress the clutch/brake to change into gears.
I've driven a few and never had to come to a 'complete stop' to change gears. You just release the clutch and shift while using the momentum to carry you forward, then let up on the clutch. There's no need to come to a stop at all. Ever try coming to a complete stop then shifting your mower into fifth and letting off the clutch?
The starter's circuit can only be closed when the mower has the clutch/brake depressed, however whether or not the circuit is fully closed and current reaches the starter is governed by key position.
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