More than likely your problem is going to be that the spools not seated properly. I bought a met 100 a few months ago and I couldn’t cast it without it blowing up. Fiddled with the brake settings and cast control knobs and nothing seems to help. I noticed that the reel seemed to have some resistance when reeling in line also. So I took the spool out yet again ( back off the cast control knob all the way before removing the spool anytime you remove a spool ) I had to put the spool back in the reel two or three times to get it to seat properly. When it finally went in correctly I felt the difference immediately. ( though it didn’t seem like I’d done anything different than the previous times I’d put the spool back in but something was obviously different bc the change was very noticeable and immediate when cranking the handle to reel in the line ) this cured the backlash issue as well. Now with two brakes on internally and the external dial between 3&4 I can launch a 3/8 oz bladed jig a mile. By far my farthest casting reel that I currently own.