Snapping belts on Simplicity Regent lat 90's model

Hi, I have a Simplicity Regent Lawn Tractor, 38" Deck, 16HP Hydro (1693916) . Picked it up used, ran it for about a month until the belt snapped. I was turning the PTO off and on every time I went into the street so would not scalp the lawn. Trying for those dominating stripes!! Replaced the belt from a local simplicity dealer (I dont think it was a simplicity belt, it looked similar in color but it did not say simplicity on it), that one lasted a couple weeks until it also broke. (Clean break, almost like it was cut or snapped) Upon inspection the belt line seemed pretty steep from the idler pulley to the PTO. Like a 10 or 15 degree downward slant (see pic) set at the highest cut level. The belt would also roll over and twist around 30 percent of time when engaging the PTO. This is my first riding mower so I am not sure about the "kick" when engaging the PTO. Is the Deck supposed to move almost kick when you engage the PTO?

So at this point, I figured I would tune it up. Replaced arbor bearings and the foam piece in between the arbor plates and one of the brass hubs which had started to eat the right side bearing. Cleaned and re greased the arbors. Took about 1/8 " of the idler arm bushing body and matched the spacer and bushings to fit with new bushings to reduce the 15 degree slant. Also replaced the idler pulley and relocated the idler pulley belt guard to where I think it should be. Grinded and sanded the the underneath of the deck and rust reformed it. Sharpened the blades and got a new simplicity belt.

Got it back together tonight around 8:00 pm, I live in a quit neighborhood with infants and toddlers, so I did not want to mow at this late hour. It seemed to do fine, but still kicks when engaging the PTO? is that normal for the simplicity since they have a floating deck? I was also able to pick a belt and headlight off a dead mower at a local shop. As you can see in the pic I am using the used belt right now so that I can work the bugs out without eating a 40.00 belt.

Any input on what is normal with these mowers would be fantastic and appreciated. What Im looking for is info on degree of belt slope from idler to PTO and how much kick or shake is normal for the regents?

Thanks

Dave

Update:

Took the idler arm off again and took about another 8th inch of with the grinder and belt sander, reinstalled. Reinstalled the blades, checked all mounting points on the deck for loose point or worn holes. The belt line is now what I think is acceptable (see pic).

Kick when engaging the PTO is not sever anymore and no more deck vibration. Was finally able to cut the lawn without the belt twisting.

Time will tell if the belt snapping is fixed.

Firstly all the pulleys can only line up at one height setting, generally one in the middle.
Secondly one of the reasons for using a V belt is so they can be out of alignment.
The tensioning arm can usually swing a little to allow this to happen with out the belt jumping off.
Thirdly a strait snap comes from a sudden shock loading greater than the belt can stand.

It is more likely to happen if the belt is too tight and one of the spindles is jambed.
A bad belt angle on ground engaging decks is generally because the deck wheels are loose, mal adjusted or just plain worn out
They get very sloppy around the axels but no one replaces them till they are so worn that they no longer roll and leave drag marks in the grass.

bertsmobile1 said:

Firstly all the pulleys can only line up at one height setting, generally one in the middle.
Secondly one of the reasons for using a V belt is so they can be out of alignment.
The tensioning arm can usually swing a little to allow this to happen with out the belt jumping off.
Thirdly a strait snap comes from a sudden shock loading greater than the belt can stand.

It is more likely to happen if the belt is too tight and one of the spindles is jambed.
A bad belt angle on ground engaging decks is generally because the deck wheels are loose, mal adjusted or just plain worn out
They get very sloppy around the axels but no one replaces them till they are so worn that they no longer roll and leave drag marks in the grass.

Click to expand...

Thanks for the input. I brought the mower used so not sure what the PO did or replaced parts with.... perhaps he replaced the idler arm with one from another deck as it looked in better shape than the rest of the deck.

"Firstly all the pulleys can only line up at one height setting, generally one in the middle." I agree, but the angle looked too intense....but Im no mower mechanic!
"It is more likely to happen if the belt is too tight and one of the spindles is jambed." One of the hubs had started to eat into the bearing....this makes sense.
"Thirdly a strait snap comes from a sudden shock loading greater than the belt can stand". Makes perfect sense now that you said that. Both times the grass was wet and I think the deck may have been full of grass.

"A bad belt angle on ground engaging decks is generally because the deck wheels are loose, mal adjusted or just plain worn out" This makes sense as well, except the angle is such that the Idler was higher than the PTO. If it was the wheels, more than likely it would be the opposite? or am I missing something?

You have it right, worn ground wheels usually make the deck sit lower.
The idler pulley should have a spacer inside the bearing .
There are hundreds of different idlers where the only difference is the height of this spacer.
So was the old one the same as the new one ? It is not uncommon to find the wrong pulley in the right box.
Malaligned pulleys may cause the belt to roll only if it is too tight as can the wrong idler.
Some Idlers are very expensive while a very similar idler is 1/2 the price that may or may not work properly.

bertsmobile1 said:

You have it right, worn ground wheels usually make the deck sit lower.
The idler pulley should have a spacer inside the bearing .
There are hundreds of different idlers where the only difference is the height of this spacer.
So was the old one the same as the new one ? It is not uncommon to find the wrong pulley in the right box.
Malaligned pulleys may cause the belt to roll only if it is too tight as can the wrong idler.
Some Idlers are very expensive while a very similar idler is 1/2 the price that may or may not work properly.

Click to expand...

The new idler which said briggs and straton on it was the same as the old one that was worn out, but when I see pics of "simplicity" pulleys, they are always black, not silver. I am wondering if some simplicity dealers are selling "OEM" parts but not "simplicity parts".

I think you bring up a good point about the "too tight". I think the spring bolt (arbor mounting bolt which the spring hooks too) might have been in the wrong spot, i.e. to far outboard and should be one hole over towards inboard.

I also rebuilt the hanger bracket with new bushings as well as the adjuster nut. There was so much play in them that the deck was whipping up and hitting the PTO pulley when PTO was engaged. That resolved the heavy kick when engaging the PTO, but I imagine if the idler spring is to tight, it could also cause a kick.


I'm gonna look into the replacement pulley from "simplicity".

Thanks for the help on this.

Briggs & Stratton owns Simplicity so nothing suspicious of getting a part in a Briggs Bag.
Photos on the web are oft decades old.

bertsmobile1 said:

Briggs & Stratton owns Simplicity so nothing suspicious of getting a part in a Briggs Bag.
Photos on the web are oft decades old.

Click to expand...

So, between replacing the the bushings, grinding the idler arm and adjusting the tension on the belt, it appears to be running as it should.

The problem since I have leveled the deck now is that when I have it in the 5 height notch the deck is just barely supported by the hanger bracket and not fully floating. about an 1/8th of an inch gap between the rollers and the ground when on level asphault. The rollers do seem to be worn, so I ordered some new ones. I ordered 3 inch ID instead of 2 1/2 to get the height just right.

After digging around on the internet, I found the owners manual and in it, it says that the position 5 is for transport only and not for cutting. Position 4 gets me just 2.75 inches of cut height. Not acceptable for my lawn. Anyway... I guess this is why the angle of the belt was extreme and the belt was twisting since its not supposed to be a cut height..... Also why the rollers are just slightly off the ground. Well, between my idler arm mod and the new 3" inch rollers hopefully I will get my 3 1/2 inch cut height I want. There appears to be plenty of clearance under the deck so hopefully it works.. will update the post once I get the rollers installed and get more than one cut on the setup.

Chiming in on the idler pulley that looks to be wrong. It is a v-belt idler when it should be a flat idler pulley. I could be wrong but the back of the belt is in a v-pulley, not a flat pulley. Picture attached of the idler that I think is wrong and the type of idler I think it should be.
Wrong pulley

Right pulley. It does not have to be plastic but that was the best picture I could find for a flat idler pulley.

BlazNT said:

Chiming in on the idler pulley that looks to be wrong. It is a v-belt idler when it should be a flat idler pulley. I could be wrong but the back of the belt is in a v-pulley, not a flat pulley. Picture attached of the idler that I think is wrong and the type of idler I think it should be.
Wrong pulley
View attachment 40485
Right pulley. It does not have to be plastic but that was the best picture I could find for a flat idler pulley.
View attachment 40486

Click to expand...

Thanks. Yep, that what the pic looks like. However the pulley is actually flat in between the sloped edges so the back of the belt is actually riding on a flat surface. I found the problem. It was that I was cutting in height position 5 which the owners manual states is for transport only. I modified the several things to compensate and it is now cutting great at 3.5 inches in the "5" position. no belt breakage yet. I guess these mowers cut low.

I ordered some 3" OD rollers with a 5/8"id from the intraweb - Deck Roller / Grasshopper 603725 - raised my deck perfectly I had to trim one for them to fit. But got me cutting at 3.5 inches.

Also changed the fluid in the tranny to some 20 50 synthetic. Runs strong!