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216 Randomly slows down.

5K views 52 replies 9 participants last post by  HeyYou 
#1 ·
JD 216, belt drive system. All belts are new. Variator spring has been adjusted to just about max tension. But, randomly, the tractor will just slow down to a crawl. Nothing changes, the ground is flat.... grass is the same height, I don't touch anything.... it just slows down. It will run slow for anywhere from six to fifty feet, and then it will speed back up to what I actually WANT to go.

Any ideas why it does that?
 
#3 ·
No clue how much pressure it is supposed to exert.... no way to measure it either. It seems, that if I pull up on the clutch pedal hard enough, usually, it will go back up to speed, and be fine again for a bit...... motor seems to have increased load when I try that though... no idea what thats all about.

Would a failing deck bearing cause it to do that?

It almost seems cyclical.... go for a couple hundred yards, slows down to a crawl.... on my last round of mowing, it would starting slowing down again at almost the same spot each time, which was down hill......
 
#7 ·
Sounds very weird. You're gonna have to look into that. Never heard anything happen with the drive system with the deck switched on, but not with the deck off.
 
#9 ·
You most likely have adjusted but do it again,sounds like it is out of adjustment.
 
#11 ·
Yep Variator,been a looooong day for me.If the deck slows,the drive belt from the pto is too loose,thghten the "t" handle on the front,it has to be real tight.
 
#13 ·
You are probably right,either an idler OR new belt or both.
 
#15 ·
Any oil leaks? Could be something getting on a belt or a pulley.
 
#17 ·
Ok, checked the deck, and there was indeed a bearing there that was toast. Mowing the lawn again today, the deck runs MUCH quieter.....

I tightened the variator spring as much as possible. (left just enough threads for the locknut on one side, and ran the other all the way down.) Readjusted as well. Everything seems to be where it should be, belts are new.. (both of them.) But, I still get the random slowdown. It seems distance related more than anything else. When it slows, is is pretty much in the same area in my rounds. The ground is flat, the grass isn't tall, there is no hill..... it isn't struggling at all. It just slows down..... Seems to be slowly bleeding off speed till it gets to a tipping point, that it just slows to a crawl. Sometimes, if I pull up hard on the clutch pedal, it will accelerate back to speed, and stay there for a while. Other times, I can pull as hard as I want, an it won't speed up at all..... let it run for another 10 or 20 feet, and then I can pull it up.

This is rather annoying.... especially when I am trying to beat a storm to get the lawn done. (I lost... yard ain't done, raining like monsoon season.... guess I am done for a while. :) )

Ideas? Thoughts?
 
#19 ·
If it was sticking though, it would tend to stay at the speed at managed to get to though, wouldn't it? At the moment, it will cruise along at the desired speed for several minutes, then, out of nowhere, slows to a crawl...... let it go for a minute or three, and it will usually speed right back up.

I just don't get it.........

Is there something I can lube the center sheave with? Service manual seems to think I shouldn't have to do that.......
 
#20 ·
I use lucas oil treatment and then clean it off with a rag AND you pulley may be worn to the extent it sticks just sometime,that thing is busy so it could need replacing.
 
#21 ·
I was thinking about this rather hard....... and remembered that I shortened the secondary belt idler tension spring, in hopes of preventing it from flopping off every time I released the clutch....... that didn't help, replacing the belt did. It occured to me that the additional spring tension is still there..... and the variator might be 'interpreting' that as additional load.... Going to fix that spring, and see if that doesn't change anything.
 
#22 ·
Sorry for the double post....

Put the idler pulley tension spring for the secondary drive belt back to 'stock'. Didn't seem to make any difference.

Would a carb problem possibly cause this??? I suspect that the carb is a bit varnished up from sitting over the winter, as it requires a bit of choke to run smooth.

Edit: It seems section 30 (fuel system) is conspicuously absent from the PDF version of the service manual that I have......
 
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