Revs surging

[quailrunner]

My boat (SR 185 sport) is running fine, but the revs started surging this morning - running about 20 mph, on plane, w. 3-4 people in the boat, revs go to 4000 and then down to about 3200 (where they usually are). Doe not appear to do this constantly - only a few times on the way up to speed, and after a turn. Boat does not sound any different. Oil pressure, temp is fine. Only thing that looks different is the lube reservoir is a little (2-3 OZ) lower than last time I checked (not below the low limit). We had a bad time getting it into the lift last night - chop was bad - and banged the bow once pretty hard - no damage that I can see, and the drive was nowhere near the lift.

I'm going to fill the reservoir to the top line and take her out again. Any suggestions - drive leak? Time for the I/O to be pulled?

Thanks for any input!

 

[Redhook98]

Either your trimmed improperly, or a slightly spun prop-hub.

 

[quailrunner]

It was the trim - thanks, and sorry to take so long to respond.