How do I purge hydraulic system? Also run away starter

[logdog]

To anyone who can help, I have a 1972 OMC 1700 that has water in the hydraulic system. And a starting issue. 1) My first issue is draining the tank. I can't seem to find a drain plug. Is the tank the same area as the chain gear? I loosened up the plate, but no drainage. But that being said, I have already pumped most of the fluid out (I think). 2) Once drained, is it better to take off all the hoses, and blow them out, or just keep running new fluid through them? 3) Is there a filter that needs to be replaced? 4) Do I have to bleed the system once completed? If so how do I do that? 5) And lastly, when I turn the key to start the engine, after I release the key the starter continues to engage. Is this a sylinoid issue? Thanks in advance for any help, James

 

[Tazza]

The only way to get the lot out is to remove all the hoses and cylinders/pumps/motors. It can be done, but massive job.
The wya i do it is to pump it out the aux couplings, when it's spitting, shut down. Drain the hydro filter, fill the reserve tank with cheap fluid and run it, lift/tilt and drive around. Drain the tank again till the colour is right.
It will use a lot of oil, just put cheap stuff in till it's the right colour then drop and replace with good fluid and a new filter.
It should self bleed.