New MTD Owner with a question

JoshDennis1982

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Hello everyone. I'm sure this is a question that has been beat to death but I just can't seem to find an answer. Quick backstory to the mower in question (Yard Machines 638RL 38") is I just got it from a new home owner. A guy got a house and it was in the shed. He knew nothing about it or where the key was. I got it cheap. When I got it home all the fuel had been drained, fresh oil in the crankcase, and all of the connectors where unplugged. Whoever put this one away...my hat is off to you good sir. I have everything squared away except for one connector. There is a small female spade connector on the left side of the mower under the seat. I can't find a place this wire seems to want to go. It almost seems long enough to go to the solenoid but there are no open spots to put it. I'm so confused. Any chance anyone here has one to help a brother out?
 

tom3

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Is this a hydro with the shift on the fender? Could be a wire going to the shifter as a reverse indicator. Look under the fender for the connection. Could be something for the seat too?
 

bertsmobile1

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Some manual boxes have a neutral switch to prevent cranking in gear
Try looking for a parts break down for the mower or owners manual.
One of them will have a wiring diagram in it.
Also check to see if it gets powered at any time.
The mower could also have been fitted with a 4 pole solenoid in which case the wire would be a ground for the solenoid.
 

tom3

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Maybe some help?

yard-machine-638-rl-wiring-diagram-for-yard-machine-riding-lawn-mower-wiring-diagram-3-8-yard-machine-wiring-diagram-yard-machine-638rl-manual.jpg
 

JoshDennis1982

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First off, huge thank you for the wiring diagram. For some reason google was no help on finding that. The wire I was talking about went to the reverse. I looked under the shifter and there was a male spade just begging for a connector. Still didn't want to crank so I got to messing with anywhere there could be a safety and my pto lever is a little loose. Slid forward, pulled back and held and it cranks. Poured in a little gas and it fired with a little hesitation. Ran for a second then bogged down, started smoking horribly (imagine seafoaming an engine style smoke) and then just didn't want to run right. Initial thoughts were clean the carb, replace spark plug, and adjust valves. I let it cool off for a few hours and got to work. Pulled the spark plug and fuel poured out of the cylinder. Pulled the valve cover and the intake was a little loose and exhaust was actually a little tight. They are all adjusted up, new spark plug is at the store waiting but here is my question. The electric valve on the bottom of the carb is a type of float if I'm not mistaken. I pulled it from the bowl and turned on the ignition. The plunger didnt' move. Cranked it, plunger didn't move. Would I be wrong in thinking it might be stuck open and am in need of a new one thus causing the flooding and possibly the smoke show as well?
 

JoshDennis1982

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Quick little update, I figured if I'm going to clean the carb might as well pull it and pop the bowl off so I can see what I'm working with. Found the main jet almost completely plugged and the rubber on the float valve pretty nasty looking. Gonna slap a new valve in and get the carb cleaned out. Maybe once the gunk is out it'll actually run. I might actually have to spend some money to get it to run reliably. Hopefully a can of carb cleaner doesnt' break the bank lol.
 

bertsmobile1

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Two types of solenoids, one grounds through the body & has 1 wire
the other ground via a ground wire & has 2 wires.
Next this does not stop fuel entering the carb, it stops fuel leaving via the main jet to stop the engine running.
So you have to pull the carb off and fix the float valve that is not shutting off the fuel supply.
YOur oil level will now be high s& diluted so you will need to change the oil, run the engine fro a couple of minutes then change the oil again.
 
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