I have had my Caroni TL 1500 for 4 years. I have found the belt system to be a problem. The following applies to TL model only, it looks from the parts manual, that the TM pulley sizes are different, belt fitment may not be exactly the same.
The original belts did not last long. Replacement B43 (46") belts required chopping off .75" of the end of the adjustment screw, to allow for enough tightening without hitting the cover. Made for a tight belt loop around the tension pulley, smoked the belts.
I tried Kevlar belts, A&I Products B43K (46"). Much looser fit than standard B43 belts. I had to add a .5" bushing to the adjustment screw (and chopped some more off the end) to get tension on the belts. Ended up with extreme loop around idler pulley. Smoked the belts on 18" weed growth first time out.
I tried the next size smaller belt, Kevlar A&I Products B42K (45"). Required some force to get it on: To turn puleys, a 3' prybar on the shaft yoke (tractor end disconnected, of course) & least 3 clamps & wood blocks pressing belt on. To adjust, I made a replacement longer adjustment screw to allow the idler to back way off, barely touching the belts at first.
Smaller belt, Kevlar A&I Products B42K (45") has worked fine so far. At this point the hassle of getting it on the only negative. I think 45.5" belt would work well, if they exist.
If a better work-around has been found, I'd like to hear it.