Need help with bandsaw tensioner/spring

I’ve got a Carter Cobra on my Delta 14. You couldn’t hurt that thing if you ran over it . I would first check my blade length though…I’ve seen over(and)undersized bands. I’d also have a look at the threads on your tensioning rod for a stripped area. Either condition would produce the problem you describe

-- One of these hammers oughta fix that...

I had a cheapo 14 incher thirty years or so ago that I experianced a similar problem with. I found finally that the block was binding in the ways. I took it all apart, filed the ways and cleaned up the block then life was good (till the motor fried) BTW I was not suggesting that your saw is a cheapo but mine was for sure. It was an early china special and in that era they were really bad.