Hi all. I have just acquired a bare bones '85 K100. All it has is a windscreen. I would like to convert it to an LT which I know was first produced in 1987. Does anyone know what years the  LT body parts (fairings) will fit. Any other info would be greatly appreciated. Same handlebars? Same cables? Hardware? Etc. Thanks in advance. This is my winter project. New England weather isn't too great in the winter.

I have an 84RT and a 92LT and have swapped a few parts between them.

For the most part as far as I can see the entire of the fairing and its brackets are identical so if you can get your hands on a complete fairing, storage boxes, storage box frames, storage box lids, leg panels, interior baffles, spider bracket and the and all the bits that go with it you are a lot of the way there.

Chances are you will buy a new screen as most used ones are not great.

If you are lucky it will have the indicators/turn signals and headlight in it. If not you will need them.

If you have the flat or RS bars, you will be looking for new RT/LT handlebars, RT/LT cables and the brake pipe from the front master cylinder to the splitter. I changed my bars and ordered a used one, when it came it was for the LT heated grips. The bars are different at the grip ends but you simply cut the lugs off if you don't use heated grips. If you plan on fitting the BMW ones make sure you get the bars for them.

You may also need the impact pad for the switches and ignition mounting.

The handlebar switchgear does not change but you will have to wriggle the wiring a bit to get the extra length. Check no loose connections before you put the tank back!!

Battery/side panels changed at some point too and I don't think are interchangeable, important to know the exact model so a photo is important.

A little hint too, if you don't know the state of the head bearings its worth doing them before you fit the fairing as its just easier to get at everything.

While you have the tank off change the fuel hoses and also the vacuum pipe and crankcase breather pipe....small money but easy to do at this time.

I think the only significant differences between years are the side covers but if you swap in an 86+ tail cowl then that shouldn't be an issue.

The one LT feature you won't be able to put on an 85 is the fuel gauge since the 85 bikes have a different fuel level sender.

Thanks for the info. I just want to clarify that my bike is not an RT. It it a plain K100. Not sure if this makes a difference or not. Thanks

Doesn't matter that your current bike is "naked" and not an RT.

Except for some idiosyncrasies common to all 85 models, your frame and engine are the same.

Another thing to consider would be swapping in some forks from a newer K100 or K75 is order to get a factory fork brace.

Duck

Would I be right in thinking the change on the fuel level gauge happened with the change from the bolted down tank?

If its a bare bones K100 and has a radiator cowl and belly pan those parts are worth a lot.

The change from the bolted down tank did happen at the same time in the model changes from 85 to 86 but the changes are not directly related to each other for any reason I can discern.

Not sure about pre 85 (since we didn't get those in the US) but all of the 85 tanks I've seen have the bottom of the tank stamped the same as the later tanks where the newer fuel level sender went.  But of course there isn't a hole in the middle of it.

On my 84 RT the tank is bolted down at the rear with a single 10mm bolt and that changed with the revision that took the grab handles away from the seat which changed from steel to plastic base.

92KK 84WW Olaf wrote:On my 84 RT the tank is bolted down at the rear with a single 10mm bolt and that changed with the revision that took the grab handles away from the seat which changed from steel to plastic base.

Olaf, I think those changes were separate, as my two '85 RTs have the pinned tank, not bolted, but have the grab handles incorporated in the (metal based) seat.

On further pondering, I'm not sure how correct that is, as both these bikes were originally single seat Police bikes.

Ultimately, anything that is attached can be considered suspect as to its originality unless you have good knowledge of the entire provenance of the bike!

For what its worth, its my understanding that the tank with the single bolt at the back had the dual stage fuel level sensor at the front left, and the two pins and clips version had the single stage float based sensor attached underneath the tank nearer the back. Again, its my understanding that all those sensors had the fuel gauge sender as well as the warning light switch, though in many cases only the warning light switch was connected to anything.

Because of the possibility of changes over the life of any bike of that age, I suspect the presence or absence of any feature isn't usually a reliable indicator of any other part.

I'm happy for the gurus to correct my understanding of these issues.

Bill

You guys are great. A lot of information for me to digest and use as I work on my project. Keep it coming. 

Thanks!!!

I'll post photographs as I go. Thanks again.