So while working on my engine I noticed this taped up wire end...is it a accessory plug in (like heated suits etc...)? Ipmy first k bike so I’m learning...i know my battery tender is in the other side of the bike

It's always a good idea to identify the motorcycle you are working on. 

brickrider2 wrote:It's always a good idea to identify the motorcycle you are working on. 

Excellent idea!  Take a few minutes to put your bike's model and year in the signature line.  It really helps us identify what we are commenting on when giving assistance and troubleshooting tips.

The connector you are holding looks like it is the high altitude plug.  There is a matching connector with a short loop of wire that you plug in when riding above 4000 feet of altitude.  It tells the Jetronic to lean out the fuel mix to compensate for the thinner air at high altitudes. 

The only time I use mine is when I'm out West in the mountains.  I have forgotten to plug in at 6-7,000 feet and left it in down to almost sea level and honestly haven't noticed any ill effects on the performance of my K75RT.  I suspect it's more of a clean air function to meet EPA requirements than anything to improve performance.

The biggest difference I've noticed without the altitude plug is that the bike starts to idle like crap when you get up above 8,000 feet and will die if you try to idle at 10,000 feet.

Thanks.!!i live at a altitude of around 2500 ft so no worries on that note
Oh and it’s a 85 K100RT ...😃

Heresy23 wrote:Oh and it’s a 85 K100RT ...😃

Click on the Signature tab at the top of the page then put that information in your signature so it will show up as a reference below every post you make from now until the end of the world, as Point-Seven-five suggests.

Ok let’s see , think I got it now ..

I put the miles in too , good idea ....I always got lots of questions !!

Laitch wrote:

Heresy23 wrote:Oh and it’s a 85 K100RT ...

Click on the Signature tab at the top of the page then put that information in your signature so it will show up as a reference below every post you make from now until the end of the world, as Point-Seven-five suggests.

 Apparently this plug was installed only on bikes built prior to 1986, and just for the US market. with the later ones ECU adjusted for the different altitudes (and what were European buyers doing, no idea)

No, it's on US K bikes from all years.  The only exception is that the small number police Ks sold in the US don't have it. (I assume because they use the same police wiring harness as non-US K bikes.)