Jared C,
The 169 is rare Cubby compared the 1250 and there's not many of them around so I would fix up your hydro on it rather than canibalize your 169's engine for the 1250. You would have numerous challenges trying to put the 169 engine in a QL chassis.
If you haven't changed the HyTran and filter in a while, I'd start with that first and clean the siphon tube to make sure there's no blockage in it. If that don't fix it, it could be your charge pump is getting weak so you might want to swap the one of your 1250. Follow the service manual instructions for accomplishing that.
The 169 is rare Cubby compared the 1250 and there's not many of them around so I would fix up your hydro on it rather than canibalize your 169's engine for the 1250. You would have numerous challenges trying to put the 169 engine in a QL chassis.
If you haven't changed the HyTran and filter in a while, I'd start with that first and clean the siphon tube to make sure there's no blockage in it. If that don't fix it, it could be your charge pump is getting weak so you might want to swap the one of your 1250. Follow the service manual instructions for accomplishing that.