KB's K100 Project
Discussion
I seem to have a habit of picking up unloved bikes left to the elements. My latest one is this K100.
(this is after I jet washed it)
Probably the only thing that worked well on it was the radio. It provided the tunes to its own destruction.
Not going to lie, I largely gave up at this point and dropped a message to a bike breaker to come get it.
But I had a beer and thought I'd continue on - what else was I going to do? Watch Tennis?
Removing the fairing was actually not an easy job, compounded by not knowing what rust was actually a screw or bolt, and what was just rust.
Also just how long does one need their accessory wiring to be?
Anyways, I thought I'd give it a wash, and then I doused it with loads of WD-40, and then I started to kind of like it.
So I put the new battery in and tried to start it. It wants to start, and ticked over a few times, but its just going to need more love. Also, the fuel cap definitely leaked water from the wash into it. It was clear before I washed it. What made me decide to commit to it, is it started to smell like my dad's old silver wing (the exhaust smell). Instant time warp and much love.
As long as the motor internals are okay, then this is doable. Lots of replacement parts are actually fairly cheap - and I'm hoping a buddy gets his C&C machine up and running so that the fabrication side is going to be a little cheaper.
(this is after I jet washed it)
Probably the only thing that worked well on it was the radio. It provided the tunes to its own destruction.
Not going to lie, I largely gave up at this point and dropped a message to a bike breaker to come get it.
But I had a beer and thought I'd continue on - what else was I going to do? Watch Tennis?
Removing the fairing was actually not an easy job, compounded by not knowing what rust was actually a screw or bolt, and what was just rust.
Also just how long does one need their accessory wiring to be?
Anyways, I thought I'd give it a wash, and then I doused it with loads of WD-40, and then I started to kind of like it.
So I put the new battery in and tried to start it. It wants to start, and ticked over a few times, but its just going to need more love. Also, the fuel cap definitely leaked water from the wash into it. It was clear before I washed it. What made me decide to commit to it, is it started to smell like my dad's old silver wing (the exhaust smell). Instant time warp and much love.
As long as the motor internals are okay, then this is doable. Lots of replacement parts are actually fairly cheap - and I'm hoping a buddy gets his C&C machine up and running so that the fabrication side is going to be a little cheaper.
I had a k100lt years ago and a k100rs more recently
Behind the clocks is about 500g of steel plat, you can ditch that, it was meant for the naked k100, helps steering a bit.
Mine died because a sensor in the radiator caught fire or the wiring to it did.
You can fit different wheels from other k's and some R's I think I ended up with a three spoke rear from a r1100rs.
Behind the clocks is about 500g of steel plat, you can ditch that, it was meant for the naked k100, helps steering a bit.
Mine died because a sensor in the radiator caught fire or the wiring to it did.
You can fit different wheels from other k's and some R's I think I ended up with a three spoke rear from a r1100rs.
A mate of mine has one of these (actually, he has several in various states of decomposition), in very similar condition, but he uses it as his daily. I think it has around 175,000 on it now. He used to be a dairy herdsman and jokes that his Bee Em probably has more off road miles on it than most Land Rovers. I think it's had a clutch, rear diff and a wiring loom... and recently needed a sump change, due to a patch of diesel hiding in the shade under some trees.
There seems to be no shortage of cheapish spares, if you're happy with used items.
He also has a high mileage K1 (a lairy Benetton coloured superbike), in similar condition and a whole shed load of early K100s with sidecars hanging off them.
There seems to be no shortage of cheapish spares, if you're happy with used items.
He also has a high mileage K1 (a lairy Benetton coloured superbike), in similar condition and a whole shed load of early K100s with sidecars hanging off them.
Some years ago, I looked at buying a k1100RS, because I wanted the whole tourer with panniers thing.
A lot of them were quite rusty then.
I test rode a couple and ran off to buy a Ducati ST, haven't looked back.
I've always had mates with BMW bikes, but never quite got there myself, despite enjoying a short ride on various examples from R90s through GS's to K1200....
Back in the days when dinosaurs and Ford Sierras roamed the earth, as a grubby student, BMW UK were generous enough to let me have a go on the early K100. That was a revelation in its day, but 10 years later, the world had moved on.
On the test days, they had great difficuty convincing people to pull the brake lever hard enough to make the ABS do anything.
Back then, the EFI was a bigthing, but everyone soon caught up.
I did bid quite high on a nice K75 once, but didn't win. The triple was a sweet engine, but this century, it probably lacks power?
The Op's project looks quite challenging!
A lot of them were quite rusty then.
I test rode a couple and ran off to buy a Ducati ST, haven't looked back.
I've always had mates with BMW bikes, but never quite got there myself, despite enjoying a short ride on various examples from R90s through GS's to K1200....
Back in the days when dinosaurs and Ford Sierras roamed the earth, as a grubby student, BMW UK were generous enough to let me have a go on the early K100. That was a revelation in its day, but 10 years later, the world had moved on.
On the test days, they had great difficuty convincing people to pull the brake lever hard enough to make the ABS do anything.
Back then, the EFI was a bigthing, but everyone soon caught up.
I did bid quite high on a nice K75 once, but didn't win. The triple was a sweet engine, but this century, it probably lacks power?
The Op's project looks quite challenging!
I had several K100s both 8 and 16v. The engines are grossly over engineered and under stressed and will run forever with regular servicing. 100,000+ mile engines are very common.
While they were a bit of a heavy lump, the low C of G made the "brick" BMWs much easier to manage than bikes from Japan aimed at the same market though the funny switch gear really did divide opinion.
I wish the OP the best of luck with the restoration. As has been said, parts are still, in general, readily available As the bike was an RT/LT then I would recommend looking for an RS final drive. It was higher geared so made the bike feel less "busy" and more relaxed.
While they were a bit of a heavy lump, the low C of G made the "brick" BMWs much easier to manage than bikes from Japan aimed at the same market though the funny switch gear really did divide opinion.
I wish the OP the best of luck with the restoration. As has been said, parts are still, in general, readily available As the bike was an RT/LT then I would recommend looking for an RS final drive. It was higher geared so made the bike feel less "busy" and more relaxed.
Well I'm glad the missus is out of town. A steady stream of delivery vans has started to trickle into our road. 
GSXR K7 750 USD forks. Sounds a bit odd - but I wanted these first as they largely dictate a few of the early steps - which triple clamps to go for, what the colour scheme can be, what wheels and brake combos are now options etc.
A set of good condition exhaust headers. At some point there is a nice Ti set that looks great, but these were £80.....
GSXR K7 750 USD forks. Sounds a bit odd - but I wanted these first as they largely dictate a few of the early steps - which triple clamps to go for, what the colour scheme can be, what wheels and brake combos are now options etc.
A set of good condition exhaust headers. At some point there is a nice Ti set that looks great, but these were £80.....
black-k1 said:
I had several K100s both 8 and 16v. The engines are grossly over engineered and under stressed and will run forever with regular servicing. 100,000+ mile engines are very common.
While they were a bit of a heavy lump, the low C of G made the "brick" BMWs much easier to manage than
Well thats good news as this has 88k. While they were a bit of a heavy lump, the low C of G made the "brick" BMWs much easier to manage than
BSK Speedworks has a full ignition system that jumps the power from about 60hp to 95. Its a bit pricey as its a loom, ecu etc, and it will also need a set of 16v throttle-bodies, so if I trip over a lotto ticket I know what I want.
Killboy said:
black-k1 said:
I had several K100s both 8 and 16v. The engines are grossly over engineered and under stressed and will run forever with regular servicing. 100,000+ mile engines are very common.
While they were a bit of a heavy lump, the low C of G made the "brick" BMWs much easier to manage than
Well thats good news as this has 88k. While they were a bit of a heavy lump, the low C of G made the "brick" BMWs much easier to manage than
BSK Speedworks has a full ignition system that jumps the power from about 60hp to 95. Its a bit pricey as its a loom, ecu etc, and it will also need a set of 16v throttle-bodies, so if I trip over a lotto ticket I know what I want.
I do remember that there wasn't a huge amount of things you could do with the 8v engine to up its output without some very significant investment so 5bhp from an initiation change sounds about right. The 16v could be up'd to around 125bhp with a simple ECU chip change.
Anyway, good luck with the build.
black-k1 said:
The 8v engine was rated by BMW at 90bhp and the 16v at 100bhp. As I remember, the engines were designed to handle 140bhp so 90 and 100 are hardly stretching it.
I do remember that there wasn't a huge amount of things you could do with the 8v engine to up its output without some very significant investment so 5bhp from an initiation change sounds about right. The 16v could be up'd to around 125bhp with a simple ECU chip change.
Anyway, good luck with the build.
Eeer, the rated HP is engine output before drivetrain losses, which on a shaft drive is high. Standard K100 8vs dyno at about 65, and with the changes its a massive increase - take this example - 67.8 to 93.8. An 8v putting out 93 at the wheel is pretty impressive.I do remember that there wasn't a huge amount of things you could do with the 8v engine to up its output without some very significant investment so 5bhp from an initiation change sounds about right. The 16v could be up'd to around 125bhp with a simple ECU chip change.
Anyway, good luck with the build.
Killboy said:
black-k1 said:
The 8v engine was rated by BMW at 90bhp and the 16v at 100bhp. As I remember, the engines were designed to handle 140bhp so 90 and 100 are hardly stretching it.
I do remember that there wasn't a huge amount of things you could do with the 8v engine to up its output without some very significant investment so 5bhp from an initiation change sounds about right. The 16v could be up'd to around 125bhp with a simple ECU chip change.
Anyway, good luck with the build.
Eeer, the rated HP is engine output before drivetrain losses, which on a shaft drive is high. Standard K100 8vs dyno at about 65, and with the changes its a massive increase - take this example - 67.8 to 93.8. An 8v putting out 93 at the wheel is pretty impressive.I do remember that there wasn't a huge amount of things you could do with the 8v engine to up its output without some very significant investment so 5bhp from an initiation change sounds about right. The 16v could be up'd to around 125bhp with a simple ECU chip change.
Anyway, good luck with the build.
Check out: https://www.kbikeparts.com/classickbikes.com/ckb/3...
The K100 was up there performance wise with Japanese bikes of the same era that claimed around 90bhp. I've no doubt that a number of horses will have been lost over time, as with any bike of a similar age, but the losses for the shat drive are definitely not of the magnitude you have suggested.
black-k1 said:
Are you sure you're not confusing Kw with BHP?
Check out: https://www.kbikeparts.com/classickbikes.com/ckb/3...
The K100 was up there performance wise with Japanese bikes of the same era that claimed around 90bhp. I've no doubt that a number of horses will have been lost over time, as with any bike of a similar age, but the losses for the shat drive are definitely not of the magnitude you have suggested.
No. Shaft drive losses are higher than belt and chain, and its been claimed as high as 25% on older generation stuff, and new generation is looking at around 12-15%. Compared with chain its massive.Check out: https://www.kbikeparts.com/classickbikes.com/ckb/3...
The K100 was up there performance wise with Japanese bikes of the same era that claimed around 90bhp. I've no doubt that a number of horses will have been lost over time, as with any bike of a similar age, but the losses for the shat drive are definitely not of the magnitude you have suggested.
You are not going to find many "standard" K100s that dyno anywhere near 90 whp. Mid 60s is generally what 8v k100s put on the wheel. Not that it matters to me what numbers anyone wants to use for anything, the only thing I'll ever use a dyno for is before/after comparisons. There are too many variables to try work back to some manufacturers claims.
Watch the BSK SpeedWorks video - a jump from 64 to 94 by changing engine management is a sizable gain.
I progressed a little with the teardown and investigation. The thottle-bodies are really stiff, and definitely need to be completely rebuilt. I've ordered another pair off ebay too as the springs look a little beyond gone.
First up - I've had an explosion of spiders in the garage - ones I've never seen in my garage before. I think this bike is the Trojan horse. And I think I found where - I had to clean out a massive next under the tank
I also found the one clean spot the bikes has. Inside the electronics compartment.
The coolant overflow bottle is broken, but I'm not sure what to make of this. I poured just under 2 liters of coolant into it to see how much it needed. Seems to have been pretty dry.
I then dropped the coolant.
The sandy stuff doesnt seen to be that hard, and can squish a bit and come apart, but still. Looking at the waterpump cover I can see some silicon used as a gasket. [EDIT: I have now been told this is what BMW uses for gaskets on these]I wonder if it previously had a coolant leak - I'm hoping its just a seal if so.
First up - I've had an explosion of spiders in the garage - ones I've never seen in my garage before. I think this bike is the Trojan horse. And I think I found where - I had to clean out a massive next under the tank
I also found the one clean spot the bikes has. Inside the electronics compartment.
The coolant overflow bottle is broken, but I'm not sure what to make of this. I poured just under 2 liters of coolant into it to see how much it needed. Seems to have been pretty dry.
I then dropped the coolant.
The sandy stuff doesnt seen to be that hard, and can squish a bit and come apart, but still. Looking at the waterpump cover I can see some silicon used as a gasket. [EDIT: I have now been told this is what BMW uses for gaskets on these]
Edited by anonymous-user on Monday 22 July 15:43
Had some more time to work on the bike this weekend.
Almost wish I hadn't. When I pulled the airfilter I noticed some white power like substance on the clean side.
What could that be? Well, never mind the top, what the hell happened in the airbox?
I'm not sure how this all got in here other than years and years of standing. The intake pipe is too small for most rodents etc. The picture is being kind to it - it was absolutely full of leaves etc.
Remember the white stuff I mentioned above the filter?
Safe to say this is completely toast. Nothing moved in there if it should, and I dont think contact cleaner will save this. Ordered another on from Ebay quickly
Once you clean things, they do look better.
Almost wish I hadn't. When I pulled the airfilter I noticed some white power like substance on the clean side.
What could that be? Well, never mind the top, what the hell happened in the airbox?
I'm not sure how this all got in here other than years and years of standing. The intake pipe is too small for most rodents etc. The picture is being kind to it - it was absolutely full of leaves etc.
Remember the white stuff I mentioned above the filter?
Safe to say this is completely toast. Nothing moved in there if it should, and I dont think contact cleaner will save this. Ordered another on from Ebay quickly
Once you clean things, they do look better.
I started to doubt the project again. I've read on forums that the rear spline in the driveshaft are known to go if they are not maintained, so I thought I'd have a quick look and make a decision (again).
Removed the ABS stuff - wow that will lighten up the bike
Drained the gear oil
Aaaaaaand.
Cleaned up, I think they actually look good. Please say they look good.
Removed the ABS stuff - wow that will lighten up the bike
Drained the gear oil
Aaaaaaand.
Cleaned up, I think they actually look good. Please say they look good.
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