Hi all, 3 weeks and two days ago I picked up this beauty, a 1989 K100RS SE ABS:



Which of course quickly turned into this..



Upon closer inspection the stanchions are scored enough to make the forks weep and the front brakes are erring on being awful, I have a plan.. But that is for the technical section! Also I have a suspicion that someone has fitted normal K100 fork springs and not K75 "S" springs that are needed for this particular bike which is part of what makes it an SE, as the front wallows around in an almost unwieldy manner. All fun and games until the speed is high enough to make this stuff dangerous rather than interesting! Also it is now missing its gorgeous original paint and is boring silver, but oh well.

So yeah, hi! I could do with some pointers.!

You mean it took 3 weeks to find us? Welcome to the Forum.

You will find all the help and technical information you need here.

On the home page there is a section 'What to do if you have just bought a K100'. Have a look see and no doubt you will be back here. There were various upgrades over time so very useful to put in your VIN number in your signature. Any problem you meet, someone will have met it before.

After a while your K will get lonely and eventually acquire a mate. They then breed a project K. You will get to enjoy the banter and fun on the forum across the globe. There are a few K owners around you too, Sidecar Paul in Birmingham knows them inside out too so in time a few of us do meet up, swap parts etc.

When you get sorted a few little trips off to Wales might be in order.

Is that a Mini Clubman behind?

I've been googling quite a lot about K bikes over the past 3 weeks and many of the forums seem to be inhabited by devout followers of the BMW religion, quoting passages from their owner's manuals like they are commandments from a prophet and totally against the thought that someone might consider the original equipment to be a bit lacklustre or might find the design of something a bit stupid. This place though seems to actually have normal people who can think for themselves, so here I am.

VIN added, but the SE is a little different from other 8v K100RSs with the extra fuel/temperature gauges, heated grips, ABS and S forks so there might still be some confusion. A lot of it is also replacement or non-standard, previous owners lavishing all sorts of very expensive shiny bits on it, a 1990 K100LT engine, a couple of new clutches, 3 spoke wheels and many brake discs. The price of most of these parts makes me sick quite honestly, being used as I am to a 1994 CB250 which runs and runs (and runs). It came with a folder full of receipts dating back to 1998 which add up to over £7K..

A trip would be good if it proves itself to be reliable, but it has stood fairly still for the past few years so I don't fully trust it yet. There again, the plan is to ride it to Slovenia in May so I best test it some more! The last owner also did a lot of little bits himself but didn't do a very good job a lot of the time - fork oil seal not properly seated, fork gaiters slapped on and not tied in place, lots of play in the throttle cable, brakes not properly bled.. The usual. He even had the 3 spoke front wheel powder coated but it was all over the hub as well, meaning the discs didn't sit flat. That was fun to scrape off!

It is a Clubman estate sat behind, with a couple of normal round nose saloons sitting on the other side of the drive. The garage is also full of bikes, as is the shed, and there are several on the drive under covers.. It might be a problem.

One of the things about the K is that what can appear difficult can be quite easy with a bit of advice from here. This forum is indeed full of what we would call normal people who do actually think and who love these bikes mostly because they are K bikes and not necessarily because of the badge itself. We ride them, fix them, maintain them and always willing to help or offer advice.

My own RT is at the moment having quite a few jobs done, but it came at a price that makes that an attractive choice. They all have a weak spot or two, mine is getting a completely new water/oil pump. When it was opened up on Monday the entire was shot, not a cheap job, but a new one is a permanent fix. The timing chain is also being looked at and I am expecting to be paying for a new chain and tensioner but that will leave the engine 100% sorted.

If you can get your hands on a Clymer manual it will show you everything you need.

Before heading for Slovenia a few things:

Tyres more than 3 years old, would change for new. Lots of different advices on what to get, I expect anything is better than old tyres, they kill the handling completely.

Your fuel lines are high pressure and likely to be perished. A length of the correct line from BMW is small money, also get worm drive clips, make them a bit longer too so you can get at the electrics under the tank by raising it. These pipes can perish and spray fuel...Chances are you will be in and out under that tank at electrics for a while.

Fuel filter etc inside petrol tank should be replaced. If the bike as sitting the ethanol in the petrol may also have affected things inside the petrol tank.

Air filter same, but it actually slides into the air box from the side, but to get at the fuel lines you strictly need to remove the air box and when you are in there, there is a cranckcase vent to the airbox you should do. Seems the fuel line will also work for this.

Coolant change, drain plug is under the water pump and easy to access. The filler is under the petrol tank, longer fuel lines and you can slide tank back without disconnecting them....

For what its worth I would put in a new clutch cable and make sure its a genuine BMW one, they use much thicker cable.

While you are under the petrol tank clean off the earths, where the brown wires are bolted to the frame.

A load of new brake discs and a couple of new clutches does not make sense, curious as to why so many clutches. One possible issue is oil contamination of the clutch from the engine seal, means pulling it apart to get at it. The seal is not expensive, but means removal of clutch and flywheel. There is an option of an oil resistant clutch plate, your receipts might show what type was fitted. I did think the 89Rs was 16 valve, but the LT engine is 8 valve so you might need to pop up the engine number as well.

To change the oil you need a BMW oil filter removal tool, cheap. If you get a genuine BMW filter it comes with an o ring and crush washer that you will need.

There is no reason why the K wont do that trip to Slovenia when you have sorted what you see. They love a long rin and will take that comfortable sitting at 5,000 r

Now if all this goes wrong, the top end of the K can also be recycled to turn the Mini A series engine into a fuel injected 8 or 16 valve twin overhead cam unit....

So far all I've found is that anything I try is bafflingly difficult - there are roughly a million screws holding the fairing together, the fork caps are incredibly difficult to remove without some sort of special clamp to shove the cap down against the fork spring, the side panels are still a mystery to me and the tank seems to be designed by Satan himself. No doubt you get used to it but even trying to look at the handlebar clamps turned into a job I had to leave and read up on. I do have a Clymer manual, as well as a useless Haynes manual, but unless you have at least an overview of what you're trying to do it's not as helfpul as it could be. For example the Clymer manual tries to describe how to refurbish the original Sachs forks, as well as the Sport forks and the later Brembo forks.. It just ends up a confusing mess if you've never taken them to bits before.

The tyres are new, just like the clutch and its cable and many other things. The previous owner spent much more time replacing bits than wearing them out, though I have a suspicion he was chasing a little gremlin the bike has - it doesn't pick up cleanly from idle if you give it a big handful. Once it's above idle it's fine, and it runs great apart from this on long runs and to the redline so I don't think anything is too far off, perhaps just some adjustment of the TPS or whatever else there is in all this injection gubbins.

The engine was replaced in mid April 2011 by James Sherlock, I am hoping they would have used new hoses but until I manage to remove the tank I don't know. There are some snazzy BMW stamped jubilee clips holding on the throttle bodies though so I'm hopeful! The '89 SE was sort of the last of the line of 8v K100s, a celebration of what had been with all the goodies on it. Sadly that means I get the old brakes and the shaft jacks the rear up.. Oh well. So much to do, but the rain won't let me!

forget about all the bad things .....you really wont notice them at all once you get all the other things right

hundreds of thousands of these things were made ...an they have lasted well ...given that the right things are done with some sort of regularity .

big boys mechano ,,, is an apt description

get your self some decent purpose built tools for all the allen keys and the job is half over before you start .

unreliable ....bah ....90,000 k in the last 3 and a bit years on this old 86 clunker (weekend rider )  

just get it right and enjoy the ride ....no comparisons are needed from other machines

they go and stop  real well with just the gear fitted as supplied

Don't get too frustrated. Once you know where the fairing screws are you can get the essentials off in 10 minutes provided a previous owner hasn't messed them up on you. Its finding them the first time.........The K is a bit like Meccano but some bits can be tricky until you now them.

The engine change sounds a good thing, at that point I would also wishfully hope the rear engine seal was good, clutch good etc. and spline lube done so may not be too bad. Probably a good sign if it got a new clutch and cable at that time. My own experience with forks is the potential problems suggest getting someone to do them. I have done them before but between sticking stanchions, bolts that would not unbolt and more when the LT got head bearings I would let someone do them and check the head bearings.

Maybe someone nearer to you might be enticed over with a beer to have a look. Trust me, there are potentially a few issues but they can be sorted. You will then discover how good the K is and how long they will last.

The side panels are a push fit into rubber grommets, at top left and top right, you pull them out and there is supposed to be a tab with a hole that engages over a pin facing sideways on the frame. The tabs break off and may be missing. Some of us replace the tabs, some of us do without, some spend a fortune on a new side panel that will also break. You can probably see the rear one when you open the seat, the front one is actually in the petrol tank at the base.

I think I understand how the side panels come off, it's just taking that leap and trying not to break one! I will try and have a go tomorrow, it's not supposed to be raining all day..

If the fork springs are correct and I cannot bleed any more air out of the brakes I would love for someone who knows what they're doing to come give it a try. It is quite possible mine is much worse than normal in terms of both brakes and suspension, and i would like to know for sure. If there's no one nearby I have been advised by a friend to give Jim Hill a ring in Long Eaton, he hopefully wouldn't charge for a quick test.

These fork caps though, why Sachs why?? 

You might have a bike that's been a bit neglected but they do come round! Its more like you are doing a few years maintenance at the one time.

Fork oil changes should be done, its easy to get the oil out, harder to get it in. A syringe and a length of pipe was recommended by I think Sidecar Paul [apologies if I have that wrong but I am not taking credit for another's ideas]. But I know from experience getting forks off a bike that they have been in for 20 years can be troublesome, but once done........May be wise as its likely the head bearings may not be too good. On my LT a head bearing job turned into a fork dismantling job and needed a bit of heavy engineering to separate the parts. I didn't do the forks though as the stanchions were pitted and corroded up high.

My brakes were a bit suspect so I have new pads and a fluid change, rear disc in hand. A lot of people are critical of the effectiveness of the brakes but I have no complaint.

In time you will be on first name terms in Motorworks or Motobins, excellent for good used parts.

You look like you are working outside, how are you for tools and other gear?

I am impressed you are not looking at taking the top off the engine and putting it in the Mini.....or else it must/should be a 1275 engine....

I wouldn't say the bike has been neglected at all, more the previous owner didn't exactly focus on the important bits - he was too busy replacing all the bolts with new stainless ones and sorting out these rare wheels. I don't understand that at all, but then he likely wouldn't understand my performance first and sod how it looks approach.

A syringe and length of pipe sounds good, the hole is too small for a funnel now that I think about it. I can get the forks out, that is not a problem now that I have replaced the rounded lower yoke clamping bolts, which I hear are a common feature. It's just these caps, and all I want to do is see what the springs are. I really hope there's something stamped or printed on them, it'd be a complete waste of time and effort if there isn't.

I see a lot of conflicting opinions on these 2 pot Brembo brakes, ranging from "they're okay" to "they're not okay". After a quick blast around Derbyshire's tiniest roads mine are definitely not okay, serious fade was apparent and I actually couldn't stop for one turn, I had to carry straight on past it. Since the Police could use them though they must capable of more, otherwise they would have been a liability if used at speed. I am a member of the GBBikers forum and there is a guy on there with an '85 K100RT who reckons the pads make quite a difference, he recommends Brembo pads over BMW or Ferodo which are what I have now. That might help, but them Brembo pads ain't cheap!

I'm working at the very front of the garage now, it's too full of bikes and Mini bits to get the K in there and be able to work on it easily. Unfortunately that means the door has to stay open, so if it's raining I'm not working on it! I'm pretty good for tools though, already got a good allen bit set and other stuff you tend to need.

It is a 1275 in that Clubman, but there are also 998 and 1098 blocks in the garage and a 998 in one of the saloons. I can't deny my Dad has been mentioning it, but I have to remind him I'm already kind of using the head on this engine..!

maybe your Dad should buy a K1100 take the engine for the Mini and you put the front end on your K100. Two happy people, brakes forks and mainstand sorted for you. Sell off what you need.

Please, there is a 16v K100RT just down the road which has been sat in a garage for 15 years after its owner died. It's already hard to resist!

What's the difference with the mainstand? Mine already has what appears to be a cast item instead of the bent pipe jobby that is on the front of the manuals, is that original?

Ha your main stand seems to be already sorted then. Its a common modification, but you have to take the whole thing, side stand too. It also allows you to fit wider tyres.....you have those I think. The original one is a bent pipe jobby as you put it. I have the original one on mine....

Now that K100RT down the road needs to move your direction, but mindful that after 15 years parked up you need to replace pretty much every bit of rubber.

Going back to the brakes lots say they are not good, personally I never had a problem. The master cylinders can be upgraded.....to a bigger one. Some of the pads are sintered and I think the calipers were modified slightly so the sintered pads would not fit in the earlier calipers.

When you say the tyres are new is that new new as in recently put on, or unused new 5 years ago? If you didn't put them on check the date code on the side. Its not unheard of here that the 'new tyres' were made in 1998......lethal.

Do you know how much oil is in the forks? A change of oil may help and would sort out the oil level for you.

I strongly suspect that some or all of your brake issues stem from the fact that they have been modified.

To begin with, the discs are solid instead of drilled and I suspect they are cheap, cast, after-market items.

Next, in this photo:



The ABS toothed ring is on the right-hand disc. I'm prepared to be corrected but I've never seen the ABS on anything the left-hand side.

The ABS sensor is mounted on the right-hand calliper. Again, I've only ever seen it on the left.

Your bike is, as you've said, a "Bitsa". The trouble with that for subsequent owners is to work out where the bits have come from and how they've been made to fit or matched with OE parts.

My starting point would be to match discs and pads (some pad types work better with cast or stainless discs).

The two-pot Brembo set-up is perfectly adequate. It's only real weakness is in the master-cylinder piston diameter, it's small and requires more effort from the user. It can feel soft if you are used to a system that requires less effort.

Al the K75/K100 with ABS had the ring and sensor on the right side untill the 16v engines and even then the 8v engine bikes still were on the right on the front.

RicK G wrote:Al the K75/K100 with ABS had the ring and sensor on the right side untill the 16v engines and even then the 8v engine bikes still were on the right on the front.

Bloody hell. It must be the onset of Alzheimers.

 

Don't worry I wont say a thing.

You say that there is a 16v K100RT down the road, don't be so sure. I think that the 16v 1000cc engine was only fitted to the RS and the RT kept the 8v, but I may be wrong (1989-1991).
If you think pads and discs are expensive then look at the prices for the 4 pot floating discs! I believe that I paid nearly £300 for new discs and pads from EBC and they were the cheapest around.
If you want a nice head for a Mini then rather than all the work to fit a K head, just get hold of a 12G295 proper mini head, skim it 30 thou and bolt it onto the 1098 engine with a single 1 1/2" SU, and lower the front cones buy 15mm. The car will go like stink!

The tyres are only from 2011, no worries there. No idea on the level of fork oil but some (a lot?) will have escaped past the seal by now anyway. Are the forks particularly sensitive to the oil level?

The discs are indeed cast and aftermarket, they are original BMW carriers with the old disc and its rivets removed and a new disc bolted on in its place. I do wonder if the fact they are solid is affecting the braking performance, but I think there's something else at play - probably some air left in the system thanks to the miles of tubing required for the ABS stuff. It is quite adequate for pootling along, but if something happens and I need the brakes they aren't there. Riding the thing at speed is an exercise in forward planning and road reading, which is tiring if kept up all day.

The bike down the road is a 1992 (J reg) and is registered as 998cc, but I have not seen it in person so cannot say for sure. I have a funny feeling I'll be learning about Ks with this 8v, sell it and buy the one down the road - £500 and it would be mine. Only if it is a 16v though, and only if it's reasonable (rubbery fuelly bits aside).

bikerboy wrote:If you want a nice head for a Mini then rather than all the work to fit a K head, just get hold of a 12G295 proper mini head, skim it 30 thou and bolt it onto the 1098 engine with a single 1 1/2" SU, and lower the front cones buy 15mm. The car will go like stink!

This used to be exactly what was in the Clubman estate (almost). It was okay, better with twin 1 1/4s but drank fuel. The 1275 that is in it now has an almost lairy cam but Dad saw fit to keep the the 1 1/4s for more midrange, makes no sense to me and it seems stifled but it's his toy not mine. I'm sticking with bikes, even this Meccano set is easier to work on.