Helping to check cylinder condition on a used 850 that a friend bought from a rental place. We drained as much coolant as we could out of the reservoir by swapping the lowest hose on it with one going into a catch, but we couldn't get it out of the head that way. We ended up just opening the head up hoping it had drained out of the head (when the big line out of it was clear), but it had not. Any tips for the future there? Is there a secret coolant drain bolt somewhere to drain the block? Would rather not need to desperately clean out the cylinders any time it's opened up.