Purchase 1991 K100RS Questions

[carockwell]

A 1991 K100RS has come up for sale that might be a good deal for me. I come from an 83 Airhead and I don't know much about these bikes. I like the idea that it can handle freeways at 80+ with no problems, has ABS, radial tires, and gets better gas mileage than my Airhead. I know the bike is little rough cosmetically and it looks like I would need to replace all the rubber hoses and vent lines, Mileage is 33K. Can anybody give me any ideas on what areas I should look inspect closely before purchasing? Anything unique to the model?

[SugarHillCTD]

Right off the top of my head and some of the topics seen on
http://www.k11og.org/forum/index.php


Fork seals

ABS function (these things seem to have a mind of their own)

Any leaks:
front of engine- timing cover & water pump
left side-valve cover & exhaust header nuts
right side- oil sight glass
rear/bottom- weep hole below the clutch

mirrors tight? Check out adding "leashes"

sidestand tight or loose- check the sidestand switch function

idle (throttle body sync might be needed if idle isn't even)
or coupler at alternator might be worn.

brake light switches

Others will add in their input

Good luck,
John

[Beemer01]

http://www.verrill.com/moto/kbikebuyingguide.shtml

You'll probably notice the additional horsepower.

I have an 85 K100RS and a 2003 1150GS. I have to say, the 85 K is a more sophisticated machine in many, many ways... an interesting comment given the fact the the GS is almost 20 years newer! :stick

But - I can't ride the RS offroad and the GS does this better.:clap

[rmarkr]

Rubber parts will start to fail - o rings, seals, hoses - check them. The exhaust system is prone to fatigue cracking, the drive line needs lubing. There is a lot of wiring, the connectors need to be in good shape - both brake light switches need to work reliably (ABS). Gunk in the tank can lead to filter/pump issues. The throttle bodies should be synced for smooth idle and running.

Sure its old, heavy, tall and long, but is still a great ride. They come into their own at 80 - 100 mph. Ample power, comfort, great brakes - a real mile eater.

[nh7robmw]

While I've never owned or ridden one of the 16-valve jobs I can certainly be entusiastic about your potential purchase.

I used to have a FYK ('85 K100RS) and that bike was a solid blast. Gobs of power and really felt like it was on rails above 80mph. I often cruised the deserted roads of New Mexico at 90-120mph back in the day...

Get a good radar detector and wire it into your helmet---as you will not be content at most legal speeds, IMO.:laugh

Lot's of good points already made here about what to check out on the bike. One more thing to know is (what I've heard around here and other forums) that the 16-valve models are a bit more difficult when it comes to adjusting the valves than the earlier 8-valve models. They also will vibrate (buzz through the bars and pegs) under 80mph and run hot.

But bang for the buck and long-distance ability is darn hard to beat!

Good luck in checking the bike out and making a deal. Plz post pictures if you do.

I still miss my K100, although I'm quite happy with my K75S nowadays.

[58058D]

Though it is true that the 16 valve DHC is more difficult to adjust, other than the initial 600 mile correction (which I was told was unusual), my '93 never needed adjusting. My 1200RS got its first adjustment at 111,000 last spring. As far as running hot, many of us noted that the 1100s seemed to be designed to run hotter than our '85 Ks, as the fan seemed to come on later/hotter. But, I did learn that I never rode it in jeans or I could easily get a heat rash on my calves. A 'stitch or leathers were never a problem even in 100+ degrees. With over 220K on this style bike, I am only now entertaining the new Wedge style....you will enjoy that 91 assuming it meets your inspection criteria.

[dzimbric]

A 1991 K100RS ... I like the idea that it can handle freeways at 80+ with no problems, has ABS, radial tires, and gets better gas mileage than my Airhead.


I just picked up my newest to me brick. A K1100LT and pappa is gonna need to put the Valentine on this bike. 60 mph at 3500 and the book says max rpm is 8950 max CONTINUOS RPM is 8500.

You can roll 5th from 30 to 130 in about 10 seconds. It's a lot different than my R bike but I love them both.

Have fun because you may not go back.

[Carguz]

I have an 85 RS converted with higher (RT) bars.

Total blast! It cruises at 100 with ease and leaves no prisoners. Don't apologize for it's age. It is contemporary without trying to be because it's technology was really out there. Eat your heart out Japan. It is reliable and a daily driver. (Mine is even older than yours.)

Carlos

[grandparipper]

I bought a 1991 K100RS from an enthusiast with 105,000 miles on it. It buzzes some when under 75 miles an hour and I think the RPMs are higher than they should be, but it all seems to work really well at speeds I am not supposed to go.
I had to take the water/oil pump in to be re-worked at the Fife, WA BMW store and they were wonderful to me as a cheapskate do-it-yourselfer. They took the time to explain what I should do and what they should do and why.
Have a pre-sale inspection by a pro done. It is money well spent, especially if you decide not to buy it.
I put accessory lights to be seen better. Wash it up to get a good look at everything and go!
The mirrors should give you a good look at your elbows! They are pretty pathetic. I would like to install a second set of spacers/clips on mine to get an extra 1/2 inch of viewing range, but I have not figured out how to go about it yet.

Enjoy it! I love mine!

Grandpa Ripper

[Sailingfool]

I bought an '87 K100RS a year ago with 131,000 on the it, and just turned over 139 last weekend. They are awesome. I delight in showing off the odometer, and virtually everyone thinks it's 13,900 miles. A timeless design that is very comfortable and fast on the long tour. It's a thermonuclear heat pump on hot days, and buzzy from 50-70 mph, really comes into its own at 75-95.

The bags are fantastic too...hope they come with. Mine did, and I thought I'd rarely have them on, but as it turns out, I never take them off! Expensive and hard to find used.

Good luck, and don't schedule ride to to polish chrome!