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Engine cut out

#1

M

Mojoboots

Mower was running, quit suddenly running and started smoking from this part. ( see photo) IMG_2405.jpegIMG_2405.jpegIMG_2405.jpegTurned key to off and pulled the plug out of this part whatever it is and it quit smoking. Haven’t try to start it in fear of making it worse. What am I dealing with here? Thanks in advance, I’m not mechanical at all! I change air filter and engine oil regularly however.


#2

R

Rivets

You’ve disconnected the fuel solenoid which shuts off the fuel when you shut down the engine. Will not start unless you reconnect it. Before doing anything check your oil level and see if it is over the full mark and smells like fuel. If it does the float needle in the carb is sticking in the open position. What color is the smoke? Report back.


#3

I

ILENGINE

Rivets said:
You’ve disconnected the fuel solenoid which shuts off the fuel when you shut down the engine. Will not start unless you reconnect it. Before doing anything check your oil level and see if it is over the full mark and smells like fuel. If it does the float needle in the carb is sticking in the open position. What color is the smoke? Report back.
Click to expand...
I think the smoke he was referring to was the electrical smoke from the shorted solenoid/connector.

Seems like that is the 3rd or 4th solenoid I have heard about or encountered this year.


#4

M

Mojoboots

Rivets said:
You’ve disconnected the fuel solenoid which shuts off the fuel when you shut down the engine. Will not start unless you reconnect it. Before doing anything check your oil level and see if it is over the full mark and smells like fuel. If it does the float needle in the carb is sticking in the open position. What color is the smoke? Report back.
Click to expand...
The engine oil level is below the fill mark but within normal range.Cannot detect fuel smell from oil reservoir. Smoke was black. The plastic white tab with the black and grey wires was burnt had black residue on it and had started to melt. I pulled it as it was glowing red.


#5

M

Mojoboots

Mojoboots said:
The engine oil level is below the fill mark but within normal range.Cannot detect fuel smell from oil reservoir. Smoke was black. The plastic white tab with the black and grey wires was burnt had black residue on it and had started to melt. I pulled it as it was glowing red.
Click to expand...


#6

M

Mojoboots

ILENGINE said:
I think the smoke he was referring to was the electrical smoke from the shorted solenoid/connector.

Seems like that is the 3rd or 4th solenoid I have heard about or encountered this year.
Click to expand...
yes, it was smoking from the plug, then starting to glow red at the plug blackening and melting it…is this something I can replace myself?


#7

M

Mojoboots

Are solenoid problems serious? is this something I can repair?


#8

R

Rivets

They are easy to replace, but I have my doubts that it is the cause of your problem without testing it first. I would check the wires going to the solenoid first, looking for a spot where the insulation is rubbed through.


#9

M

Mojoboots

Rivets said:
They are easy to replace, but I have my doubts that it is the cause of your problem without testing it first. I would check the wires going to the solenoid first, looking for a spot where the insulation is rubbed through.
Click to expand...
Ok thanks!


#10

M

Mojoboots

Mojoboots said:
Ok thanks!
Click to expand...
Traced wires and they look good throughout their lengths…only damage I can see is where they terminate in the plug, which is burned and melted. Perhaps trying to replace the wiring first before addressing the solonoid?


#11

M

Mojoboots

The two prong plug which enters the solenoid is burnt on the ground side…any thoughts?


#12

I

ILENGINE

My thoughts would be the coil in the solenoid has shorted and the pin for the negative side may be the weak point therefore the high resistance cause the smoking and damage.


#13

StarTech

StarTech

No just replace both the solenoid, terminals, and connector housing as the magic smoke is already gone bye bye.


#14

F

Freddie21

Leave the connector unplugged, pinch the fuel line just before the carb, using a thin 1\2" open end wrench, remove the solenoid. Gas will spill from the carb bowl. Catch it. If possible, leave the carb bowl in place.

On the end of the solenoid is a little plunger. Many have rubber tips. Using side cutters, cut the plunger off close to the body of the solenoid. Reinstall the solenoid in the card and snug it in. Try to start the engine. It should run.

You can use it this was or replace the solenoid. These are installed to prevent backfiring, or run-on, after the key is turned off. My Toro machines backfire even with them in. If so, just lower the idle speed before shutting off.


#15

M

Mojoboots

Freddie21 said:
Leave the connector unplugged, pinch the fuel line just before the carb, using a thin 1\2" open end wrench, remove the solenoid. Gas will spill from the carb bowl. Catch it. If possible, leave the carb bowl in place.

On the end of the solenoid is a little plunger. Many have rubber tips. Using side cutters, cut the plunger off close to the body of the solenoid. Reinstall the solenoid in the card and snug it in. Try to start the engine. It should run.

You can use it this was or replace the solenoid. These are installed to prevent backfiring, or run-on, after the key is turned off. My Toro machines backfire even with them in. If so, just lower the idle speed before shutting off.
Click to expand...
Good morning,
what would cause the ground wire at the plug to heat up and burn?
thank you


#16

C

Cajun power

the most likely cause of this issue is:

the connector itself is shorting the two wires and thus you have a dead short. this WILL cook the connector and produce the magic smoke,even though it's not a great deal of electrical power.

It could be the the solenoid is internally shorting also...and the same things happens: dead short.

this conditions is quite hazardous as the anti back fire solenoid is just below the carb fuel bowl...any fuel vapor or leaks can start a fire. so be VERY CAREFUL when dealing with this issue.

there are a number of ways to solve this problem. first and foremost, use safety first methods. Do not hook this back up back up until you have identified root cause and made correct repairs.

what does the SAFE CORRECT REPAIR look like?
a. replace the entire wiring run from the mid disconnect harness all the way up to and including the anti back fire connector. it's possible that the wiring insulation is good, but the conductor internally has been damaged..so replace this entire length of wiring from the mid disconnect harness AND the connector. Replace the anti back fire solenoid. Make sure the anti back fire solenoid is properly grounded to the engine...there should be a wire that does that. Make sure it is installed and tight.
b. You can also consider just deleting the anti back fire solenoid. the only purpose of these devices, that are common failure components, is to prevent a back fire. If you are concerned about back fire, just idle down before turning the engine off. There are some youtube videos that show how to delete the anti back fire solenoid. This involves making a small modification to the wiring connector and stowing it away and making it safe so there are no sparks and no shorts. And a fine threaded bolt to hold the carb fuel bowl. This anti back fire solenoid is a common failure item because the pin gets gummed up and does not retract...this results in a no start or fuel delivery problem, a lean condition..and over time a stuck pin will eventually cause the internal solenoid to short and overheat...and this is probably what has happened. I've deleted anti back fire solenoids in ALL my mowers with no problems. I just idle down before engine shutdown. It's rare that a back fire actually happens. I can live with a back fire here and there. I cannot and do not have the time to replace expensive anti back fire solenoid that fail often! I would also recommend installing a inline fuel shut off valve close to the carb fuel inlet. This can be used to starve the engine of fuel in a alternate way to shutdown and it also helps when long term storage (coupled with draining all the fuel from the carb fuel bowl, by simply removing the fine threaded bolt! then let the engine starve from fuel...then you have less chances of gummy fuel in the carb main jet and float pin!)


#17

D

dwzkd

It looks like the connector part of the solenoid came loose with the harness side. Remove the solenoid side of the connector and look at the pins/terminals for damage (black, shorting, etc). Use an ohm meter and verify the ground in the connector is connected to ground and that the power (likely white wire) has +12v when the key is in the run position.
If you get 0v, check for a fuse in the harness somewhere. If it checks good, you should be able to replace the solenoid.

Make sure that the terminals in the harness side are getting a tight connection to the new solenoid. I assume the solenoid will have male spade terminals. You may be able to pinch the harness side to get a better connection.

Let us know how it goes...


#18

C

crazykartman

dwzkd said:
It looks like the connector part of the solenoid came loose with the harness side. Remove the solenoid side of the connector and look at the pins/terminals for damage (black, shorting, etc). Use an ohm meter and verify the ground in the connector is connected to ground and that the power (likely white wire) has +12v when the key is in the run position.
If you get 0v, check for a fuse in the harness somewhere. If it checks good, you should be able to replace the solenoid.

Make sure that the terminals in the harness side are getting a tight connection to the new solenoid. I assume the solenoid will have male spade terminals. You may be able to pinch the harness side to get a better connection.

Let us know how it goes...
Click to expand...
I don’t disagree with dwzkd, however I don’t go to quite those lengths. If you don’t have a problem with an afterfire (which doesn’t damage anything, just a loud noise as unburned fuel dripping into the hot muffler), simply eliminating the solenoid is the way I do it. I do this at least a half dozen times a year for my customers.

With the engine cold, simply unplug the solenoid connector, pinch the fuel line, remove the solenoid from the carburetor, break off the pintle/plunger on the solenoid, reinstall the solenoid, and do not reconnect the connector.

There is now no way for the carburetor to prevent fuel flow when running, and with it unplugged there is no possibility for any sparks.


#19

S

SamB

Rivets said:
They are easy to replace, but I have my doubts that it is the cause of your problem without testing it first. I would check the wires going to the solenoid first, looking for a spot where the insulation is rubbed through.
Click to expand...
Wouldn't a chaffed wire, before going to the fuel solenoid, melt there at the chafe rather than at the carb plug?


#20

R

Rivets

No always, especially if it is the ground wire on a 2 wire circuit.


#21

S

smallenginerepairs

It sounds like the problem is in the plug itself. It could be shorted out within the plug. Cut the wires before the plug, instal a new plug. The solenoid either works or dosent. when you repair the wires and plug, remove the solenoid from the carb and watch the nedle valve on the end of the solenoid. When you turn the key to run position the needle should be pulled back within the solenoid to allow fuel into the carb. If the needle dosen't move when you put your key in start position you need a new solenoid too. I hope this helps you, Pete


#22

S

slomo

I would install a 1 amp inline fuse on that circuit. Then figure out why there is excessive draw on it. Bad carb solenoid is an easy fix.

Don't need a mower fire.


#23

M

Mojoboots

Mojoboots said:
Mower was running, quit suddenly running and started smoking from this part. ( see photo) View attachment 66578View attachment 66578View attachment 66578Turned key to off and pulled the plug out of this part whatever it is and it quit smoking. Haven’t try to start it in fear of making it worse. What am I dealing with here? Thanks in advance, I’m not mechanical at all! I change air filter and engine oil regularly however.
Click to expand...
Problem resolved. Replaced solenoid and cable with new. Problem appeared to be in the solenoid itself.


#24

S

slomo

I appreciate you coming back with a fix action. Nice work sir.


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