Mower/brush cutter belt tension

[jkulloa]

Anyone have an opinion on
what the proper way to tension the belts
on the brush cutter for the PT1850 is?
I just bought a used unit, and the belts seem
loose; kinda floppy, actually. I am afraid to over-
tension them as the belt is so long, and is likely
expensive.

 

[cqaigy2]

I'd say, if it's not slipping, it's probably tight enough.

 

[jkulloa]

I was hoping for some guide to the tension.
It’s hard to tell if, or how much, it is slipping,
but I think it probably is (at least a little). I may
just try to get it about as tight as the belt on my
riding mower, which is a fair bit looser than my
old truck’s fan belt.

 

[tjkubota93]

1/2" deflection with thumb in a 12"-16" span?

 

[jkulloa]

1/2" deflection with thumb in a 12"-16" span?

I think that sounds about right! I will give that a shot, and report back with any results.
Thanks!!

 

[BobRip]

I think that sounds about right! I will give that a shot, and report back with any results.
Thanks!!

I was ordering a new belt for my 422 finish mower and Keith told me that most belt failures occur because it is too tight. Just tight enough so it does not slip when mowing is how he described it. I plan to grab the blade and see if I can make it slip. I hope this helps.

 

[jkulloa]

My belt was really loose. A bit floppy when I checked it as part of my first service of the mower. I did not tighten it initially and while it cut grass pretty well, it cut unevenly in the thick stuff. It seemed to get worse later, so I started this thread. Upon rechecking it yesterday in order to tighten the belt up a bit, I found it had fallen off, and only the center blade was turning! I put it back on and tightened it as per tjkubota93痴 suggestion and it has been cutting real well! Bogs the tractor down in really thick stuff, which suggests it is not slipping. I hope it is not too tight... In any event, it is cutting very well now!

 

[jkulloa]

I was ordering a new belt for my 422 finish mower and Keith told me that most belt failures occur because it is too tight. Just tight enough so it does not slip when mowing is how he described it. I plan to grab the blade and see if I can make it slip. I hope this helps.

I hope I did not get it too tight. The belt is in really good shape, and the mower is cutting well right now. It seems like the belt should last quite a while. I think it should be good for several seasons of moderate usage (I mow about 20 acres three times a year - I think that is light to moderate for this machine). I guess I will find out...

 

[MossRoad]

If it were me, I'd get a spare belt just to have on-hand. I've learned with my PT425 that the belt will break half-way through your mowing the day before the graduation party! :laughing: I've only replaced the belt twice in 17 years, started my third one last year. Got a spare on the wall for the next time.

 

[cqaigy2]

Speaking of belts. I saw a few youtube videos about protecting belts, etc. from uv degradation using something like 303. I'm going to give it a try on my wiper blades on my car and serpentine belt on my ranger.