I have a 1990 Suzuki DT 2-stroke (85 hp). Today when I took it out on the water, I would have the throttle set at maybe 3/4 full and all of a sudden, I would hear the motor rev and the boat would slow down. It was like all of a sudden, the gears weren't catching to spin the prop. I moved the shifter back and forth a bit, then the prop would catch and the boat would cruise fine. For what it's worth, on the way back from fishing, I set the throttle at 3/4 full again and it ran great. Has anyone had a similar experience with this type of motor and if so, what may be the cause? Also, the shifter is a bit touchy. In reverse especially, you can hear the teeth of the gears clack unless you really slam it into gear. It does it a little less so when you first shift to forward. Please help!

Almost sounds like the hub is breaking lose inside the prop.  Have you struck anything recently with the prop?

sounds like prop slippage. Check the hub and prop.

From the way he's talking about it being touchy when shifting, it may have jumped out of gear. Sounds like he needs to check for loss motion and adjust his shift cable and linkage and make sure shift rod going to lower unit is making it's full travel into gear before he starts paying for a rehub. Normally, once a hub spins, it don't get better and go back to working as if it had never spun.  Could very well be the hub, but I would check everything else first.