170 shut off problems

wv109323

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I started the mowing season by replacing the transaxle drive belt. During that job, the gas tank was removed, steering was unbolted, mower deck removed ETC. The top bushing for the steering column was dislocated so I had to remove some wiring to to put the top bushing back in place.
Now the mower has a problem that I can not diagnose. While mowing it will begin to sputter and sometimes quit. It will always restart when the blades are disengaged and transmission in neutral. The most likely times are when the grade changes and the engine governor should be opening up the throttle but not always. Also at times the engine dies when the blades are engaged. Engage the blades several times and suddenly everything seems normal for a while.
I thought at first it was the governor. I looked at that and found no reason to suspect it. But I am now leaning toward an electrical problem.
Is there a set of contacts in the blade engagement switch or electric clutch circuit that will kill the ignition? Anyone had a seat safety switch or transaxle neutral switch to act like this?
Where can I find an electrical diagram for this mower?
Other ideas?
 

wv109323

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I need the WD for a 170 that was made in the 1990 to 1992 time frame. My model number has no "D" in it. My mower has a 38" deck with a 14HP Kawasaki engine.
 

toddsyr

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This one?

URL unfurl="true"]https://schematron.org/john-deere-model-d170-wiring-diagram.html[/URL]
Todd K Stearns
 

wv109323

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The mower/engine now will die every time I engage the blades. The switch for the electric blade clutch has two wire connectors plugged into it. One has three wires and the second 2 wires. If I unplug the two wire connector the blades will engage when I throw the switch. The two wires are gray and green. Anybody know what the two wires are for?
 

toddsyr

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I changed the link above to a different wiring diagram page. The first image is for a 175 but below that it's for a 170. Is this of help for you?
 

wv109323

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Thank You for your efforts toddsyr. That is it. The problem was the seat safety switch. It was very erratic in making/breaking contact. If you checked it with an ohm meter you thought it was ok but the slightest wiggle it make contact and caused the engine to miss or quit.
 

bertsmobile1

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The switch is a very simple sliding contact
The plunger has a bit of brass on it that connected the left & right terminals ( on most ) when depressed.
Cut your old one in 1/2 and you will appreciate how simple they are.
They cop a beating from dirt & weather plus unlike the brake or PTO or MIR switches , which are the same, they are perpetually sliding back & forth as you bounce up & down in the seat .
As such they wear faster .
I often pop a self tapper in the end of the plunger so it depresses the contacts a bit further so they are not making & breaking contact 20 times a minute while you are mowing.
Mostly it is done to ZTRS with owners who are frustrated NASCAR drivers & take it out on their mowers .
 

toddsyr

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Thank You for your efforts toddsyr. That is it. The problem was the seat safety switch. It was very erratic in making/breaking contact. If you checked it with an ohm meter you thought it was ok but the slightest wiggle it make contact and caused the engine to miss or quit.
You're quite welcome, glad to be of help. It's great to hear that you have it figured out.
 
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