88 K75S Few questions, Spark Plugs, Wire Plug and Mystery Vac Line

[fastxl]

Doing a bit of work to an 88 K75S I inherited. New Fuel injectors, Intake Manifolds, Fuel Pump, Spark Plugs, All the stuff to get it running good.

What is this Plug? Battery Charger?

I found this line that is plugged. What is if for? Looks like it goes the crankcase.

Is it normal to use 2 different brand and part number spark plugs??? (This is sarcasm, I know better but apparently someone didn't)

[frankenduck]

The photos you attached don't work.

[Chaos]

not sure about the wire, the vac line was a fuel tank vent that vented into the crankcase (I think, might be wrong) but it was a bad idea and most bikes had it plugged so they would run right.  As for the oddball plug, it happens

[fastxl]

Thanks for sorting out the pics. I think the plug/wire might be for some sort of battery trickle charger?

[Chaos]

it sort of looks like a broken plunger switch for the brake light, but those are next to the hand lever or foot pedal. 

[frankenduck]

I found this line that is plugged. What is if for? Looks like it goes the crankcase.

Mystery hose: http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/mysteryhose/mysteryhose.htm

[fastxl]

The mystery plug is attached to the plastic cover that covers the coils. To me it looks like a cig lighter only smaller, it even had a flip up cover on it like a cig lighter in car. I don't even see on the wire diagram in the repair manual I have.

[Laitch]

The mystery plug is attached to the plastic cover that covers the coils.

It's an accessory power socket, so your impression of it is correct. I receives a BMW-style plug and can be used for heated gear or other accessories.

[Laitch]

This is an image of a BMW plug to SAE plug adaptor. The BMW plug is on the right; the SAE is on the left.

[The Mighty Gryphon]

That outlet that was on the coil cover is a broken accessory socket. 

The plugged hose goes to a small hose barb on the top of the engine block near at the front of the engine near the coolant temperature sender.  It was part of the California air quality requirements that was later disabled.

[frankenduck]

The "BMW" power socket uses a Powerlet or Hella plug.  It's connected to the battery so, in addition to being used for output to heated gear or whatever accessory, it can also be used to keep the battery charged with a trickle charger.