Yard-man single belt 46" deck problem.

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
Finally got well enough to tackle some of the jobs been in here since Christmas.
Run into a problem with a 2017 Yardman 23 Auto Special 13AP604H671. Ser # 1B167H20372
I think it must either be an export only special or a Canadian made one because that model number comes up "Not Found "
Now it uses a very narrow 46" ( H ) deck with a single PTO/blade belt, not the usual 2 belt system with double pulley.

According to my wholesaler it takes an A122 ( US size ) belt # 954-04118 belt if fitted with a 4.5" idler or a # 954- 04153 belt when fitted with a 3.5" idler.
Now the first problem is both these belts code out to being the same size ( which they can't be ).

Second problem is according to the belt routing decal on the deck, the tension pulley is on the tension side of the drive pulley and not on the slack side where it should be.
Third problem is the belt is loose so does not drive the blades.
The next size down MTD deck ( A 119.25) belt is too short.
Any one have any experience with this deck before I take to it with the welder ?
Is the catalogue wrong & it should be a B section belt ?
The pulleys are deep enough and it has an electric PTO .
Not sure if the tension pulley plate has been installed wrong but if it is reversed so the sprung pulley is where it should be the 4.5" flat idler would have a B section turning too tight a reverse bend between it & the center blade pulley.
 

ILENGINE

Lawn Pro
Joined
May 6, 2010
Threads
39
Messages
9,866
Bert the diagram that I found from the canadian MTD site shows the 954-04118 belt but they use two 4.25 inch idler pulleys. the belt routing is from the right side of the engine pulley to the right idler pulley, around the center spindle then to the right spindle and then to the left spindle behind the right idler pulley back to the engine.

MTD used that setup for a few years here in the states, but didn't last long. Belts were a major issue for the deck. They used a 1/2 inch belt on a 46 inch deck with a large engine. the right idler pulley acts mainly like the deck belt tension pulley and the left pulley was a shock load pulley for engagement and hitting other objects with the blades to help prevent breaking the belt. The problem was the system would allow the belt to slip under load.



the owners manual for your mower is the 4th one down on the list. IPL near the end of the manual
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
Once again I am eternally in your debt.
When searching the MTD site from here the numbers bring up nothing so there must be a search bar from Aust ISPs ( happens with a lot of stuff to protect the IP of the local dealers )
So it all looks factory correct.
It still seems wrong to have a tension pulley pulling on the tension side of the drive pulley but I can pull it apart now & check the springs are right way round & pulleys are correct.
Looks like both idlers are the same in the IPL ( only 1 part number ) and this deck has a 6" & 4.5" idler.
If I swap the center spindle idler with a 4.5" one then the shorter belt will probably be a nice fit .
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
55
Messages
14,683
I think most of us are still in your debt, as you’ve helped most of us out many times. Just glad we could be on the other side of the sharing. Good Luck and glad to see your doing a little more than sitting around, as I know you are still not back 100%. Hope everything keeps improving.
 

PTmowerMech

Lawn Addict
Joined
Apr 16, 2018
Threads
387
Messages
2,956
Bert, IIRC, this is the first time I've ever seen you post a question. Seriously, I had to look to see if someone had stole your screen name.
 

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
I am here to learn just as much as any one else .
FWIW
the actual idler system is not as per shown on the IPL and the main problem was grass accumulation causing the lower tension arm to rust solid in place and added to that some one had replaced both idlers with the wrong sized pulleys. The small one is from 1990 ( #756-0437 ) and the larger 5" one has no numbers on it. And this was supposedly done by the dealer who originally sold it.
Got both 3.5" & 4.5" idlers in stock so will now see what it looks like with the right bits
Was looking good after a clean up then the stepped spacer that allows the top tension arm to pivot broke.
So it is one step forward 2 steps back.
Going to do a bit of a redesign as I will have to turn up a new spacer so I will replace the common pivot bolt with a shouldered one thus when nipped up it can not pinch the lower arm.
Still a bit of a dinky system and I can see the left idler tossing the belt with gay abandon unless I fit a retainer.
 
Last edited:

bertsmobile1

Lawn Royalty
Joined
Nov 29, 2014
Threads
64
Messages
24,647
So closure of this thread as well.
The customer came today to collect the mower which is not as good as I would have liked but when he saw me testing it in 5' tall grass & weeds on the road verge he was very happy.
The belt jumps off at any cutting height lower than 2 but he mows pasture with it so it is always at full height.
MY parts supplier lists belts for both 2 same size idler pulleys and 2 different sized idler pulleys which is listed as a mid season change , so I have fitted the shorter belt A 119.5" ( A121.5 US )
The stepped spacer has been upgraded by MTD with a slightly taller one to give more clearance for the lower tension arm.
Even then I had to add a shim washer to prevent it locking up when the bolt is tightened down fully.
To prevent the new stepped spacer braking like the old one did I fitted a heavy blade washer on top of it for more support of the flange .

I have never seen a deck where the belt run is only strait at the highest cutting level so to me the first pulley would need to be about 2" tall with a deep flange to prevent the belt running off the pulley but I could not find a pulley any where near the right diameter to do that.
The best solution would be to fit a new LH spindle with a double pulley the same as the USA models which would raise the height of the driven pulley 2.5 " and make for a normal belt run.

I do like a challenge and writing this now I really should have fitted the 2" tall TORO idler and a suitably shorter belt ( would have been good to have thought of that before, but such is life ).
Unfortunatly the AUSTRALIAN GA catalogue mentions a shorter belt for the smaller pulley but does not list the pulley just that it is 3.25" and the parts book shows them as being 1" tall.
 

PTmowerMech

Lawn Addict
Joined
Apr 16, 2018
Threads
387
Messages
2,956
Good job Bert.

If pro's like you don't get a challenge every so often, you'd get bored. Me thinks you'd make a great engineer.
 
Top