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PTO engaging stalls engine.


wickedace

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A mid 90's Sovereign 18. I got this tractor last year to do snow duty at my vacation home. It seemed a good runner when I got it.

Anyway towards the end of last winter it broke the snow blower belt. I chalked it up to bad alignment of the pulleys because the belt was shredded and let it sit until this weekend. I have a new belt and put it on in about a half hour, careful to align the pulleys.

I have a 7117 at home doing 4 season duty so I am familiar with the systems swapping in the mower deck and snow blower.

Belt put on and pulleys adjusted I fired her up. As soon as I engaged the PTO the engine stalled. Started it up again and verified the blower was moving on engagement. It was but stalled immediately.

I worked back to the PTO and even with the belt off it stalls when engaging. Now the shaft spins freely on the bevel gear box and drives the hydro pump fine, I can drive around the yard to my hearts content. I just can't get the PTO to drive my snow blower.

Is there something in the cone clutch that would do this?

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If it stalls without a belt on it you must have something binding up in the cone clutch, check to see if the pulley rubs on anything with the pto engaged, can you turn the pulley with the pto disengaged?

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"check to see if the pulley rubs on anything with the pto engaged"

Rick

I won't get back to the tractor until next weekend hopefully. Any hands on will need to wait for now.

The PTO had worked, I cut grass after getting the tractor and cleared snow with the blower a couple snow falls. So to answer your question I would have to say it does not rub.

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There is another possibility. Does it "stall" or does it shut down? I would think 18 HP throttled up would take one heck of a bind to bring it to a quick and hard stop. Engaged and dead, you could try to turn the engine over by hand and determine any major resistance (nut and wrench on the crank, a good grip with two hands on the driveshaft coupler, etc.) The other thought, and I am not sure how this would happen, but maybe electrical? A faulty nanny? I think the nanny's only kill the starter circuit on these, but maybe they also, on a mid 90's, are killing the engine when the seat nanny, PTO nanny, etc., are not all in sync. In other words, maybe the PTZO nanny doesn't recognize you being on the seat, and as soon as you engage it kills the engine?

Just a thought. Those that are more familiar with the safety electronics on the later Sovereigns may be of help.

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Have you released the belt tensioner to see if it is a clutch problem or something else. You should be able to do a little bit with out harming the belt.

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quote:Originally posted by Brettw

There is another possibility. Does it "stall" or does it shut down? I would think 18 HP throttled up would take one heck of a bind to bring it to a quick and hard stop. Engaged and dead, you could try to turn the engine over by hand and determine any major resistance (nut and wrench on the crank, a good grip with two hands on the driveshaft coupler, etc.) The other thought, and I am not sure how this would happen, but maybe electrical? A faulty nanny? I think the nanny's only kill the starter circuit on these, but maybe they also, on a mid 90's, are killing the engine when the seat nanny, PTO nanny, etc., are not all in sync. In other words, maybe the PTZO nanny doesn't recognize you being on the seat, and as soon as you engage it kills the engine?Just a thought. Those that are more familiar with the safety electronics on the later Sovereigns may be of help.


id="quote">
id="quote">I can verify that a newer sovereign will shut down when getting off the seat with the pto engaged or the hydro lever out of neutral. I would guess that any sovereign with the safety switch under the seat would do this if not disabled.
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Brettw and DanD

I think you two are on to something. I was standing alongside the tractor at a safe distance from moving parts where I could watch things as I engaged. Never gave a thought to lowering the rear cowl and sitting down.

Sometimes I am my own worst enemy!

Thanks guys.

I'll let you know next week.

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Here is a little bit of text from the large frame service manual.

SEAT SWITCH TESTS

All Sovereign models with product numbers above

1691382 came with safety switches. Several switches

have been used over the years ALL are N/O (normally

open) switches.

This is referring to the safety switches on the seat.

I can tell you that if everything is working correctly, a mid 90's Sovereign 18 will immediately shut down if you try to engage the PTO when you are not sitting on the seat. I believe that a 7117 like your other tractor may or may not be this way. If the 7117 is older, it will just not start if the PTO is engaged or the hydro lever is not in neutral. Once running, then there is nothing. Newer 7117's will be like the newer tractors as described in this thread.

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Ok...I'm the dummy.

As promised I'm reporting back with my results.

This morning I put the belt on and pulled back the tension spring. Fired her up allowing a bit of warm up to cycle the oil. Plopped my but in the seat, ran up the rev's and flipped the pto engage lever. It's a miracle! Runs like a charm!

Thanks for indulging me.

Mike

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