Re: what this parts called
1) Shift gears when in the "shift range" area. The rest is self explanatory
2) Don't know. Never had a Merc with one. Could be throttle tension or idle stop control.
3) Trolling lever. Locks or unlocks the motor and allows it to tilt while underway.
4) That's the gear shift.
5 & 6) That's a decorative cover. May provide access to the steering tube for removal. Again I'm not too familiar with Mercs.
7) That is the choke. It's in the open position.
8) That's the flush port. Its for flushing the water passages out or "running on muffs" so to speak.
#2 is the friction setting for the twist grip. You can use it to tighten the twist control to keep it in place - i.e. for trolling, etc.
#8 - it is indeed a flush port, but not for use in running the engine. It is for simply flushing out the cooling system with the engine not running. It is not designed to feed water into the water pump itself, therefore you can damage the water pump if you run the engine only using the flush port.
To use the flush port, you remove the slotted screw. You need a fitting that adapts a garden hose to that threaded hole. Those adapters are available at almost any boat shop.
