What is the best way to see if your belt is to tite? What is proper way to measure tension and what is acceptable.
As soft 02 points out there is a dedicated tension tool, the only Harley tool it is essential to buy in IMHO, especially if you do any of your own servicing. If you buy a new one it comes with instructions. They sometimes turn up secondhand on Ebay.
i would look into a chain conversion,belts should definitely not break in the fashion you have stated but for around 600.you could install chain drive.