2008 Exmark Mule Belt Issues

[LazerAS]

Hi,
I have a 2008 Lazer AS with the Kohler Command Pro 25HP, running an Extreme PTO clutch and a 60" Ultra (Series 4, I think) deck. I am having issues with the mule belt tension. I have replaced the belt (103-4014 Rotary, should be the correct part number @ around 116 inches). The belt is routed properly but flops around and slips with at least a few inches of slack. My understanding is that the right side idler pulley is the only adjustment point and that the bolt should be at the top of the slot with a fresh belt install. Also, the left side idler/tensioner pulley center bolt should line up between the two holes in the side of the frame (It doesn't, and sits well below the bottom hole).
At what should be maximum adjustment I have almost no blade speed. 'I have tried new belts and shorter belts to no avail, and I am tired of the down time. I may be missing something here... My deck assist pedal was frozen up recently and I thought that might have affected the tension, but it is fixed and I still have the same issue. Everything has been greased and the pulleys spin well, the right side idler has a slight bearing noise. Is the idler pulley bearing replaceable (Press)?

 

[LazerAS]

Bump,

No replies, I thought someone might chime in to save my lawn:wink: What would cause the belt to not be able to be tensioned? The tensioner spring seems to be working properly. I am at a loss for what to do, I can't be the only one who has had this issue.

Also, the pulley that the mule belt and deck belt attach to spins freely, but I have read posts about the (sheave?) being bent and throwing belts. My belt does not throw, it flops around a bit (slipping) and runs the blades at a lower rpm, for example: Cutting dry 6" grass at a 4 inch deck height, it bogs down and has stalled. This is with me driving as slow as possible (literally crawling slower than a grocery store scooter). My engine runs great and has plenty of rpm until the blades are engaged.

Do the deck arms affect the belt alignment?

 

[shiftsuper175607]

Bump,

No replies, I thought someone might chime in to save my lawn:wink: What would cause the belt to not be able to be tensioned? The tensioner spring seems to be working properly. I am at a loss for what to do, I can't be the only one who has had this issue.

Also, the pulley that the mule belt and deck belt attach to spins freely, but I have read posts about the (sheave?) being bent and throwing belts. My belt does not throw, it flops around a bit (slipping) and runs the blades at a lower rpm, for example: Cutting dry 6" grass at a 4 inch deck height, it bogs down and has stalled. This is with me driving as slow as possible (literally crawling slower than a grocery store scooter). My engine runs great and has plenty of rpm until the blades are engaged.

Do the deck arms affect the belt alignment?

If it is the CORRECT belt...it is most likely routed wrong. Wrong direction on an idler?
Remember you may be looking at it upside down from a diagram.

 

[LazerAS]

If it is the CORRECT belt...it is most likely routed wrong. Wrong direction on an idler?
Remember you may be looking at it upside down from a diagram.

Thanks for the reply. The mule belt (deck to engine) is installed on the bottom pulley groove on the deck main pulley (If I put it in the top groove the deck drive belt would be running at an awkward angle and would shred itself. The rest of the mule belt runs underneath the bottom of the left and right pulleys at the rear of the mower, from there it is run over the top groove of the PTO pulley. The narrow part of the v is running in the groove on each pulley.

The deck belt is routed/installed properly. The mule belt is the correct part as per the dealer and was purchased with using the serial and model number for identification. I have confirmed that this is the correct belt for my mower but it doesn't work as it should. I thought it was stretched, so I bough a "correct" belt, and have also tried shorter belts, but they were too short. I had a belt that was a bit (maybe 1-2") shorter, It would take up the slack enough for the "auto" tensioner to work. I am tired of shuffling back and forth from the store to not have the right belt (too short) or still have the same issue (Rotary brand stock equivalent belt). That tells me that something else is going on here.....:confused2:

 

[supertech]

Remove the mule belt then remove the deck belt. Check all your cutter housings by hand , grab the blade and turn it. If there is any resistance or wobble that you feel when doing this then you have a cutter housing bearing going bad. I have seen these try to seize up when hot, when this happens the resistance will cause mower to bog down and try and throw the belt. The mule belt has a much harder time trying to turn the blades. Now, mule belts on exmark mowers have always flopped when running. Check all of your pulleys on the belt system, mule belt pulleys go out a lot on exmarks. Also check the gang pulley at the rear of the deck, do this with the belts off. Make sure there is no side to side slack in the bearings, these love to go bad and when they do I have seen them grind on the deck under the pulley because its cocked to one side.

 

[LazerAS]

Remove the mule belt then remove the deck belt. Check all your cutter housings by hand , grab the blade and turn it. If there is any resistance or wobble that you feel when doing this then you have a cutter housing bearing going bad. I have seen these try to seize up when hot, when this happens the resistance will cause mower to bog down and try and throw the belt. The mule belt has a much harder time trying to turn the blades. Now, mule belts on exmark mowers have always flopped when running. Check all of your pulleys on the belt system, mule belt pulleys go out a lot on exmarks. Also check the gang pulley at the rear of the deck, do this with the belts off. Make sure there is no side to side slack in the bearings, these love to go bad and when they do I have seen them grind on the deck under the pulley because its cocked to one side.

Supertech, Thanks for the reply and suggestions. I have since replaced the mule tensioner pulley and mule idler pulley as well as the proper belt. The pulleys were worn and the idler was out of round. I will check the deck spindles tomorrow, I have plans to replace them with the Triton series spindles to add serviceability and performance. All of the triton spindles I see for sale are 46-50" units (109-2102). Is this a direct bolt on for my 08 60" UltraCut?

Matt