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New on Forum: Acquired a 223,000 mile K100RT and turning it into a "Naked" cafe bike Wed Aug 13, 2014 9:15 pm
stilbo
active member
Hello all....
New on this forum but been building and racing motorcycles since 1968.. Yeah I'm "getting up there" but still building and riding bikes...
A friend finally "hung up his spurs" at the age of 80 and pretty much gave me his 1985 K100RT with only 223,000 miles on it. Tom bought the bike in 1992 with only 4,200 miles on it and proceeded to pretty much live on it for the next twenty years. Tom was an "Adventure Rider" way before anyone had used the term. When he decided to quit riding the K I asked him if he'd rather see if BMW wanted the bike for their museum.. He replied "You'll have more fun with it". It's a testament to BMW longevity in that Tom had ridden it in 49 states, Canada and Mexico and only did regular services on it and an occasional minor repair. The bike was NEVER even washed much less degreased and looked more like a farm implement than a motorcycle. Even the paint on the frame is gone. I have every receipt going back to 1992 and I documented the bikes condition in detail with about 200 photos. The fiberglass was cracked in so many places I decided to just trash it and keep all the brackets. It even had a collection of dead rodents in a couple places. But, it still ran when I picked it up. I've pulled all of the plastic and fiberglass off and power washed it before I let it into my shop. It was truely a "rat bike". I've restored more than a dozen "barn finds" over the last 40 years.. HD's, Henderson, Excelsior, Triumphs, Boxers, Indians, Guzzi's, Vintage Japanese and even a Ner-A-Car. Whenever parts or money or both are in short supply I've "Bobbed" them. This K100 is a definite candidate for minimalism...
I plan on powder coating the frame, wheels and fork tubes black. I'd do the same on all of the engine but..... I may not even need to open the engine up.. It doesn't leak anywhere and the compression seems okay. The throttle bodies look like the insides of a 1985 VW K-Jet Tronic intake manifold... Lots of nasty grease and carbon so I'll probably do a "top end" on it with rings, valves, seal and gaskets and o-rings... glass bead blast everything but the crankcase and reinstall it.. I'll probably Plasti-Gauge the main and rod bearings just out of curiosity...
Only frame mods will be to trim the fairing tabs and cut, reduce and tilt the rear frame section up to accept an aluminum cafe style seat pan with cowl.
To save $ I'm installing a 7" Honda CB750 headlamp with HID and an EMGO cafe fairing since those remind me of the Luftmeister on my old R80 and I can hide the giant gauge cluster in it. Z-bars will finish the front end mods.
Questions... (More likely to come).
1: Anyone know of a vendor that sells rebuilt final drives from cores? I own my own machine shop but I'd rather farm the final drive out to someone that can 'do them blindfolded'. The "AX" bearing sounds & feels like it's toast.
2: Compression...
My COLD readings are: 1=195 psi 2=175 psi 3=180 psi 4=190 psi
My HOT readings are: 1=140 psi 2=95 psi 3=95 psi 4=135 psi
Sound about right?
Hopefully new rings will be all it needs. I saw a very slow leak down on the two center cylinders and hopefully rebuilding the head and just a light lapping in of the valves will be all that's needed..
I live about an hour's drive from Galen Perry's BMW bone yard so I may go pickin in the next few weeks...
I want to get all of the prep work done so I can just do reassembly when the snow flies...
It's winter therapy.
Thanks all....
New on this forum but been building and racing motorcycles since 1968.. Yeah I'm "getting up there" but still building and riding bikes...
A friend finally "hung up his spurs" at the age of 80 and pretty much gave me his 1985 K100RT with only 223,000 miles on it. Tom bought the bike in 1992 with only 4,200 miles on it and proceeded to pretty much live on it for the next twenty years. Tom was an "Adventure Rider" way before anyone had used the term. When he decided to quit riding the K I asked him if he'd rather see if BMW wanted the bike for their museum.. He replied "You'll have more fun with it". It's a testament to BMW longevity in that Tom had ridden it in 49 states, Canada and Mexico and only did regular services on it and an occasional minor repair. The bike was NEVER even washed much less degreased and looked more like a farm implement than a motorcycle. Even the paint on the frame is gone. I have every receipt going back to 1992 and I documented the bikes condition in detail with about 200 photos. The fiberglass was cracked in so many places I decided to just trash it and keep all the brackets. It even had a collection of dead rodents in a couple places. But, it still ran when I picked it up. I've pulled all of the plastic and fiberglass off and power washed it before I let it into my shop. It was truely a "rat bike". I've restored more than a dozen "barn finds" over the last 40 years.. HD's, Henderson, Excelsior, Triumphs, Boxers, Indians, Guzzi's, Vintage Japanese and even a Ner-A-Car. Whenever parts or money or both are in short supply I've "Bobbed" them. This K100 is a definite candidate for minimalism...
I plan on powder coating the frame, wheels and fork tubes black. I'd do the same on all of the engine but..... I may not even need to open the engine up.. It doesn't leak anywhere and the compression seems okay. The throttle bodies look like the insides of a 1985 VW K-Jet Tronic intake manifold... Lots of nasty grease and carbon so I'll probably do a "top end" on it with rings, valves, seal and gaskets and o-rings... glass bead blast everything but the crankcase and reinstall it.. I'll probably Plasti-Gauge the main and rod bearings just out of curiosity...
Only frame mods will be to trim the fairing tabs and cut, reduce and tilt the rear frame section up to accept an aluminum cafe style seat pan with cowl.
To save $ I'm installing a 7" Honda CB750 headlamp with HID and an EMGO cafe fairing since those remind me of the Luftmeister on my old R80 and I can hide the giant gauge cluster in it. Z-bars will finish the front end mods.
Questions... (More likely to come).
1: Anyone know of a vendor that sells rebuilt final drives from cores? I own my own machine shop but I'd rather farm the final drive out to someone that can 'do them blindfolded'. The "AX" bearing sounds & feels like it's toast.
2: Compression...
My COLD readings are: 1=195 psi 2=175 psi 3=180 psi 4=190 psi
My HOT readings are: 1=140 psi 2=95 psi 3=95 psi 4=135 psi
Sound about right?
Hopefully new rings will be all it needs. I saw a very slow leak down on the two center cylinders and hopefully rebuilding the head and just a light lapping in of the valves will be all that's needed..
I live about an hour's drive from Galen Perry's BMW bone yard so I may go pickin in the next few weeks...
I want to get all of the prep work done so I can just do reassembly when the snow flies...
It's winter therapy.
Thanks all....
-o: 
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