1990 pq 290 enticer....Had drives off this past winter for gimbal repairs, filled drives to upper line on bottle. I have had the boat out 6 or 7 times and all is great, but noticed my port bottle level has dropped to the lower line on last outing. Can't find any leaks at all, drive is running fine, Im thinking maybe an air pocket that finally worked its way out. They have about 10-15 hrs on them since repairs. I wouldn't think that an air pocket would take that long to work its way out but maybe so??? Im gonna top it back off and monitor it closely....Has anyone had this happen?? Thanks!

Have to top off mine several times after a change. Often takes a couple run cycles before all the air gets burped out. Would not worry just yet, just watch it, if it's air it should settle down for you.

thanks for the reply, i'll keep an eye on it. Thanks again!

If it dropped after 10-15hrs, then I would bet you have a small leak somewhere. Usually after a lube change, if there is an air pocket, it will be gone within an hour of running.

Any signs of water in the oil? Did it drop that much after one outing or slowly over the course of the 15 hrs? If it dropped quickly, then I doubt it's a leak. If so, you would know. It's probably just air.

A way to eliminate the air pocket in the drive is when you still have the pump screwed into the bottom drain plug, remove the cap on the resivor bottle and until there is oil in the bottle. After draining the drive oil from the drive, remove the bottle and clean with mineral sprits and make sure there is no sludge build up in the bottom. Then fill the drive and bottle. Never had to worry later about filling the bottle.