Motorcycle Repair: 1985 Honda Magna Hydraulic Clutch, clutch master cylinder, mity vac

Question
Just bought a 1985 Honda Magna 500.  Runs great except after stopping and idling in first gear with the clutch depressed it sometimes loses the idle and stalls. When trying to restart with the clutch fully engaged the bike lurches forward as if the clutch wasn't pressed in at all.  Once I release the clutch and re-engage all is normal again. I am not familiar with hydraulic clutches.  It seems that if it is depressed for a long amount of time while in gear it loses its functionality.

Answer
These bikes are notorious for this. The clutch master cylinder may need to be flushed out with fresh brake fluid,DOT 3-4. The slave cylinder at the bottom will have a bleeder screw to help in flushing. If you have a friend who has or can borrow a mity-vac vaccum pump. Hook the vac line on the lower bleeder screw open up the screw and put in fresh fluid as it goes down to the slave cylinder. Don't let it run out or you will have more air in the system. Get fresh fluid in the system and try this. If it still leaks by and does,nt hold then its time to rebuild the master and the slave cylinders. The fluid will wash off with water so it wont eat the paint off.