I buddy of mine just put a 525 sc in his scarab and all was well for about 3 hrs. the other day when trying to get the boat on plane it acted like you shifted to neutral?? no loud banging or any noise for that matter. it now has no forward but does have reverse. the fluid was drained and there are not any signs of metal. any opinions? clutch cone? improperly adjusted?

I would say improperly adjusted... Mercury sells an adjustment tool cheap

They wont come out of gear without an
opposing direction shifter input

To get them to come out of gear, you have to move the shift lever in the opposite direction far enough so the ramp on the shift cam rubs the gear eccentric ring, the shift fork will then pop the cone out of the gear.....it's probably a cone/ driven gear issue.

The bravo1 has a very week floor in the forward and reverse gear. Breaks with no noise and no major metal in the oil. The adde power is the simple explaination, when he added power didhe raise the drive on the transom?

If its 1999 or older, then it more than likely, pushed the floor out of the gear. Does the serial number begin with OL or earlier? Starting with the OM serial number, they have the thick floored gears (X gears).

Just opened one up today with the same problem. It was a LH drive, so it was the upper gear. Lot of chunks of metal this time. In the past it wasnt' so drastic.

I had that problem once before and all it was is where the brass fitting goes through the gimbal. I broke and the drive would go into reverse and nuetral but no forward cause the casing would just move and not the cable to engage forward.

Ditto. Or the thrust washer under the gear broke.