# engaging pto question?



## hulkmag (Apr 2, 2004)

Ok, wasn't sure where to put this but i'll try here.As some may know from other threads I have a 14hp Deutz Allis 1914 Ultima and I am having a little snag with the electric pto engaging.The problem is that after mowing for oh i don't know 30 mins. if I shut off the pto it doesn't want to come back on.But if I let it set and like its waiting to cool down it will engage.But like i say it only does this after it has been used for a while,the first time i turn it on it engages fine and then even after that i can turn it off and on for the first 30 mins. or so but after it warms up and i turn it off it won't engage again til it sits for about another 30 mins. or so.Now I am not exact on the length of time because i have never actually timed it but it seems like 30 mins.
Anybody have any ideas on what may be causing this because i have know idea on where to even begin to look to fix this.Right now i just don't turn it off until i quit mowing if i need to go over some rocks or something i just raise the deck and lower it when i get to the other side (talk about a dust storm!).But if i stop it guarantees at least a 30 minute or so break :smoking: .


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## Neil_nassau (Feb 23, 2004)

If you have a Warner adjustable clutch (most older tractors are ) that has three bolts at 120 degree intervals ,check the airgap. It should be .012-.018. Are you blowing fuses?


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## Chipmaker (Sep 16, 2003)

Is your charging system up to par. I found a low battery on my old JD 317 would do almost that exact thing. It drove me nuts. I adjusted the air gap, and it would work, for about 30 or 40 minutes then quit, let it set awhile and it would work again. All that it was really doing when it would work is the battery would slowly charge itself while setting unused or while I was trying to figure out what was wrong. I even bought a new PTO electric clutch for JD (Ouch $$$$) and it did the same thing, only when I could not get it to crank one time is when I used another battery, and my problems went away. Never got a bat charge light or anything, so evidently it was sufficient to satisfy the bat light and keep the motor running but not handle the load of the electric clutch. Just something you may want to check.


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## Neil_nassau (Feb 23, 2004)

Good point Chip,
Engine charge system is what carries the clutch load normally. If its output is zero/low........the load falls to the battery. clutches draw a fair amount of current which the battery will handle until its charge falls below what can hold the clutch engaged.
Intermittent operation can also be caused by poor grounding. A poor ground can also cause engine main bearing failure as the clutch tries to ground through the crank and pits the main bearings balls. Kohler issued a bulletin on this in 1996..........calling it a problem for the mower manufacturer not them (rightly so) since it was a wiring harness issue.
Our Kohler rep said he's still having it show up now and then.
Electrical probs can be FUN :jumpropeb


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## Bigdog (Sep 18, 2003)

Electrically operated clutches generate a lot of heat. Add to that the engine heat and you can have problems if everything is not aligned just right. Most likely one of two things is happening. Either the heat has caused some binding up of the clutch components that releases when it cools or the clutch windings have developed a heat related resistance path effectively causing a current bypass or shunting of clutch current so that it cannot engage until it cools and the shunt is essentially removed.


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## hulkmag (Apr 2, 2004)

WOW,now you guys are getting way deeper then my experience can handle maybe i will just take it to my uncle and let him fix it cause i don't know enough to check any of that stuff except for the battery. I removed the cover on the tractor last night and good lord what a mess of wiring, electrical stuff is way over my head.But i will mention your suggestions to him so he can start somewhere.Thanks guys.Oh, and chip maker my battery does seem old but don't know how old bought the tractor used and this is the same battery tha t was on it , never really checked it because it was starting alright but i might try that first before i go any further.


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## Bigdog (Sep 18, 2003)

If the battery still has enough juice to start the tractor when it's hot, it should operate the clutch. Starting the tractor is about the biggest drain on a battery.


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## Neil_nassau (Feb 23, 2004)

If the clutches field coil resistance increased over the 3 ohms or so that makes it an electro magnet,(that value is easily checked by using a volt-ohm meter on the field coil wires).......it would draw too many amps trying to stay a magnet,and blow the fuse. Heat in these clutches usually fries the ball bearings (a mechanical failure) or the field coil (electrical) so it doesn't work at all....ever.
Intermittent operation is usually airgap,voltage source,wiring or switch related.
Good Luck


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## Chipmaker (Sep 16, 2003)

> _Originally posted by Bigdog _
> *If the battery still has enough juice to start the tractor when it's hot, it should operate the clutch. Starting the tractor is about the biggest drain on a battery. *


This is true, however, after pulling the most juiceout of abattery to start, the battery is lowered in capacity, and if the battery is not up to par, or the charging system is on the low end or high resistence at a corroded connection such as the ground, switch contacts etc, the battery may not be capable of handling what load this clutch puts on it after a period of time.

I have to agree with what Niel stated........voltage supply, wiring, switch or air gap on clutch. It common for a battery to take a charge but not to be able to hold or maintain it, due to its internal breakdown of the cells etc as it gets older.


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