2001 Mercury xr6 150.........shifted into gear fully......popped out of gear. Shifted to neutral, back into gear but did not engage.....back to neutral....back into gear and engaged.

Any ideas what's up?

I've worked on cars and trucks but I'm not outboard smart.

Thanks

My first check would be the linkage and cable adjustment. Start by removing cowl and take the shift cable off and manually shift it by the linkage. See if it fully engages each time you shift it. If it does, then the problem is probably in the cable adjustment or the control head. If it still gives a problem find the vertical rod under the front of the power head. Shift it to forward, watching the vertical rod, the see if you can push the rod a little more and get it to go in gear. If so, then the linkage has a problem or needs adjusting. If all these checks don't find the problem, it may be in the lower unit.

All this can be checked while on a hose. I recommend you check it with it idling so you don't jam/force the gears.

I'd be guessing it's the cables. Check it as Way2slow said to find out for sure.