Outdoor Power Equipment and Small Engines - Ariens EZR belt breakage

I have a EZR that is breaking the blade drive / PTO belt as soon as I engage the drive, 2 in a row.
I had removed the engine to do some repair [also replaced the PTO pulley since the original got mangled pulling it off]
After replacing the engine, I can't keep a belt on it.
I checked the pulley and there are no burrs or bends. The pulleys all appear aligned by eye as best I can look at them under the machine. The blade drive pulleys and belts after the clutch seem to move well by hand.
Is there a good way to check the electric clutch for issues? Any other thoughts about what could be going on?
its a 915-003, 15HP Kohler, 2 blade 40" cut.
Thanks for any help

I wonder if the belts are not the correct type. Belts used for this type application are generally strong enough to stall the engine rather than break.

Cheese, good call. I found the old belt that I had replaced and it's a heavier cross section than the 1/2" gates I was using. It's a bit worn, but I put i back on, and I had no problem all day.
I can't find a aftermarket replacementwith the same thickness, only thru ariens.
Thanks for the help

Is it a 1/2" or 5/8" belt? If so, most small engine shops should have belts in inch increments. Places like tractor supply and advance auto usually carry them too. If you get them from advance, ask for the drive-rite brand. They are the utility belts like your machine probably takes, and are made by Dayco.

The width looks close to a 1/2", but the depth is thicker. It's not as wide as the heaver gates belts i see around in the repair shops [I think these are labeled as 19/32]. I did find a shop that'll get a gravely belt for me in acouple days. I'll also take a look at advance auto to see if they have anything.
thanks again