will a 1 1/2 coilspring trap hold a coyote?

Sure, most of them. Depends on which 1.5 coilspring, the Montgomery RJ's held coyotes and incidental mountain lions and black bears.

But the 1.5 Victors would pop the jaws on large animals. Which is not a bad thing in bear and lion country since it meant no time was wasted releasing them.

If you're going to target coyotes move up to something like a #2 Bridger or a #3 Montana Special.

these are duke 1.5 coilspring traps

They should do OK but are far from optimum. The smallest trap I use is a 1.75 CS, and I've caught plenty of coyotes and bobcats in them. But when making sets specifically for 'yotes, I use a #3 Duke CS with offset jaws.

I would HIGHLEY suggest that you try and find a larger trap.

I would suggest a 1 3/4 with strong coils a good choice , # 2 coil ALOT better.

They sure will but they dont offer you a large target "jaws" but are quite strong.