1988 John Deere Hydro 175 - Engine stalls when I engage the blades

[SquatchLife]

Hey all,

Literally bought the tractor yesterday for $150. It was running and mowing very well when I bought it. Fast forward 24 hours and it mowed for about 10 minutes before it threw the blade belt. Got it back on and mowed for another 10 minutes when it threw the belt again. Got it back on, went to engage the blades and the mower stalled. I checked the belt to see if it was too tight and it spins freely by hand. I checked the blades themselves and they spin freely by hand. Checked the blade engagement toggle in the dash and one of the connectors was not plugged in. So I unplugged it, cleaned it up, got all the connectors plugged in and lined up and the mower still stalls when I try to engage the blades.

Should I start with replacing the toggle switch or should I look elsewhere on the mower first? Or should I be looking somewhere else entirely?

 

[oldnslo]

Is the engine stalling like under load or like you turned the key off?

I would investigate why it is throwing the blade belt. It could point you towards a problem also.

 

[SquatchLife]

It’s as if I turn the key to the off position.

I will continue to look into why it’s throwing the belt. At the moment I haven’t the slightest idea. It does look like there is a minor wave in the front pulley but not enough for the belt to throw.

 

[Richard001]

Is this what your mower deck looks like ?

If so, then I would start by looking at the support that holds the idler tenson pully and the pulley bearings. I'm guessing that they are worn and allowing the pully not to be aligned with the belt path.

Also make sure that the tension spring is doing it's job.

Richard

 

[SquatchLife]

Is this what your mower deck looks like ?


View attachment 3217737

If so, then I would start by looking at the support that holds the idler tenson pully and the pulley bearings. I'm guessing that they are worn and allowing the pully not to be aligned with the belt path.

Also make sure that the tension spring is doing it's job.

Richard

That is my mower deck. For clarification it’s actually the top pulley at the bottom of that picture that keeps throwing the belt

 

[alexpops]

when it's hooked up & attached to the tractor, check the alignment, tension, routing & clearances between the pto clutch & that pulley. Could be the power belt is loose enough to grab somewhere & stall the engine. Finally, does it look like that pulley has been removed by previous owner & put back upside down or with missing shims? Also, I'd check for any bends/flex/loose bolts on the tensioning brackets/pulleys/etc. between the pto and that deck pulley. Could be the previous owner clipped a tree/stump/rock & bent/loosened/broke something.

 

[oldnslo]

If it is like turned the key off I would suspect a safety switch is the culprit. I am not sure how many switches there are on that tractor though.

Does it have a switch on the seat for operator presence? If yes I would check that and then look for more. Hopefully someone more familiar with that model will chime in with other things to check.

 

[Mtsoxfan]

I had that model, served me well for years. If all spins freely, I would check the seat switch. That is the only safety switch for the mower deck. Check alignment of brackets/pullies, as well as bolt tension as to why it's tossing the belt.

 

[SquatchLife]

I will check that first thing in the morning and bypass it then try again. Thank you!

 

[Mtsoxfan]

You didn't mention, but even a bit of oil on belt will do same thing. My NH TC29D has a oil leak, it shredded a belt, tossed the replacement before I installed an oil shield.