Scag SW belt - Won't balance any longer

[Scagnewbie]

I have a Scag walk behind (somwhere in the '10-'18 range, belt driven) that my father inlaw gave me. It came with the ride-behind attachment.
I've been using it without issue for the last few months, and today when I started using the machine the balance between the deck and the motor already seemed a little loose. over time it became nearly impossible to use because anytime you'd hit a dip the motor would fall back and the deck would jut up so badly that one of the flywheels would make contact with the frame and spark.
Any ideas as to where to start? could it be the spring has worn out? very new to walk behind machines so I am really at a loss right now.
Thanks!

 

[slomo]

Sounds like spindle/belt replacement time.

Take pictures or even better a video and post/link here. More pics the better.


Also need mower and possibly engine numbers to assist you further. Years, colors and attachments don't help us much, to help you.

 

[slomo]

And clean your engine cooling fins while you are at it. See that red text below?

 

[Scagnewbie]

Thanks so much for the reply.
I've included a couple of pictures that show my issue. I've tried to get a video but it just won't get small enough to upload.
I did realize while taking the video, that if I have the deck lock engaged there is no issue and it still balances just fine. Once I drop the deck is when the balance goes all wonky.
Thanks again!

 

[sgkent]

if it seems loose, my first thought would be to observe where the play seems to be and look for anything broken or worn. And be aware that you may have more than one problem - meaning that the belts, blades, spindles etc., may need service, AND the looseness just aggravates the other areas that need service.