bump and grind

[phester]

I hope it turns out to be a minor problem for you step.....but......The one and only Merc I owned did something very similar. At no more than 1/4 throttle it would suddenly feel as if I was bouncing the motor off a bunch of rocks. I quickly threw it in neutral and felt the knot in my stomach swell. Long story short the "clutch dogs" in the lower unit were shot. Have you looked at your lower unit oil lately? Hope it's only a minor thing for ya Step, as I recall fixing it wasn't cheap. Best of luck.