Hello bikers

I introduced myself few days ago but now in this section I'm ready to tell you the story about my K100-RS and Will be a report of my work in progress (warning, since my native language in not english, please be patient with me). First I would like to state that BMW k100 it was and still is a masterpiece made by BMW . I remember when I saw that bike for the first time back in the early 80' while I was a student in university, I was impressed by such a different motorcyle so innovative and.... so out of reach for my budget that I've never dared to dream of having one (but deep in my heart I knew there was somewhere a k100 waiting for me ). At that time in italy we had many other motorcycles: 4 cylinder japs, v-twin guzzi and ducati, three cyl. laverda, boxer BMW, norton, triumph, and those screaming in line 6 cylinder benelli (long before honda made cbx 1000 six) but when k100 arrived it was from another planet... no story here!
I already told you how I became owner of a K100-rs but to make it short I saw that bike when it was ready to be dumped in a scrapyard, I salvaged it just in time. The bike didn't looked bad, it was covered by dust and spiderweb but no missing parts and signs of accidents, odometer was 84743km. Later I discovered that the bike has passed 7 years in a garage (parked there waiting for me). Sorry but I didn't take pictures of the bike, I was too excited to think of it, After I became legal owner of the bike I begun immediately to check the bike as soon as it reached my garage after unloading from the van. I already knew I was at the beginning of a loooong work to recover the bike to a working condition despite after a torough cleaning it looked nice and ready to go but... tires where dry and cracked, the battery was craked, white of lead sulphate, battery tray white of corrosion thanks to dripping of electrolyte from battery, tank inside was a mess of pieces of melted rubber and old gasoline deposit, rear disk rotor badly worn, some minor scratches here and there. Steering was hard due to steering head bearings jammed by the lubricating grease evolved in a kind of brown sticky tar. The engine appeared clean (no oil leaks), gearbox was working as well as the clutch, front fork very soft but damped, seemed no leaking oil, front brakes where not working that is, the lever was working but no effect on calipers, same as rear brake. The seat after 25 years is still perfect just like the exhaust system. I couldn't wait , I had to test the engine just to make sure it turns without strange noises so I hooked another battery, removed spark plugs, drop some oil inside cylinders (just to ensure lubrication). To avoid troubles I disconnected fuel pump fuse then turned the key and here lights are on. Well, electrical system seems working front and rear lights, horn and so on... the bike is returning back to life yeah! What I was looking for was to crank the engine and that I did, lukily starter engaged and made the engine turn. No strange noises and I saw sparks coming from the spark plugs; ignition seemed ok and mecanically speaking the engine semeed ok, it was enough for that day. The following days I searched and found technical documentation to support me in what appeared to be an almost complete stripdown and rebuild. Due to the long inactivity some components must be replaced, all fluids changed, battery replaced as well as tyres, perform reccomended maintenance for that mileage and check all components due to aging (the bike is 1985 that is 25 years old) like brake lines, fuel hoses and so on. I will be facing months of work but I know it is worthwhile.
Well this is enough for now, my story will continue next time bye for now

Welcome to the group. I'm looking forward to hearing all about your restoration. I restored my '88 K100RS last year and converted it to an RT this year. I think you will have lots of fun doing this project and there are many helpful people on this web site to assist. Best of luck.

flatfour wrote:warning, since my native language in not english, please be patient with me

I wish that I could write Italian the same as you write English!
Rebuilding a K100 is a lot of fun and this is the best way to learn everything about the bike.
Here is few words of advise (I rebuilt my RT too)
A good practice is to have a digital camera and to take a lot of pictures during the dismantling.
When re-assembling, if you don't remember where or how a part goes, you can refer to the pictures. Don't forget to take pictures of the cables path too (throttle, clutch, choke).
After removing a part, put the screws back (loosely) in their original location.
Mark all the electrical wires and leave the marking on after the bike is re-assembled. It makes life easier to track an electrical problem when all the connectors are already identified.
Good luck with your project.

Bert

Benvenuto alla tribuna, Flatfour, and with your vivid written descriptions and observations, I think this is going to be a good project for you, but perhaps even better for us!

hi folks
here is next episode of my k100 resurrection. Taking care of my new bike only in my spare time led me to force my schedule in the hopeless effort to stretch those 24 hours a day to look like 26 or maybe 28 so I could spend more time doing wath I like most, that is, ride and work on motorcycles. With this BMW before unscrewing a single screw I spent a good deal of time just discovering the bike, how it was made, recognising in many pieces the effort made to make that particular in that way, revealing bmw engineers concepts and ideas. I have to admit it, it was a very special motorcycle this k100 back in early eighties ans still is. Those guys in BMW made a huge effort to make that k progect a milestone non only in bmw but in motorcyle worldwide scenario. Of course now this jetronic EFI is outdated but it was the first and it was great. Well, time to start with spanners and screwdrivers. I started working on the bike by taking off the fairing... many screws here and there and several pieces and no wonder if the bike is weighing so much! Bmw didn't saved money here, fairing components are really heavy, made of thick fiberglass looking almost bulletproof (but I do know that fiberglass become brittle when old). Bydismantling the bike I was impressed by materials quality that, after 25 years are still in good shape. My goal was to drain fluids, remove tank and have it clean then check fuel pump and fuel line, replace the battery and then try to start the engine just to make sure is really working and in good shape. Tank cleaning alone it was a pain that took time and effort to be accomplished; that melted rubber was everywhere just spread all over like a black paint. By using 5 liters of acetone (not sure about spelling but it was CH3CO chemically speaking ;-) helped a lot. Another session of work was to take care of fuel pump but as I already supected it was not working to say the least. I spent a couple of hours just to take it apart hoping to make it working again but i found it was clogged, tarred, rusted, weared and some windings burned; barely good as sample that pump! I suspect that bike was left unused becouse fuel pump was giving troubles maybe not enough to stop the bike but unpleasant to use and ride then, left in a garage, those passing years and gasoline "terminated" the pump. A quick check with bmw dealers for availability and price of pump, rubber support, fuel filter, internal hoses left me with the strong impression of a costly replacement to say the least. Pump was made by bosch and easily found at almost half the price BMW charges, a compatible filter is available so all I will have to buy from BMW is that rubber sleeve to support fuel pump. Before buying parts I want to make sure I got all of them so first I have to take apart all bike then prepare parts list and then only buy them. I was tempted to start immediately with fuel pump so I could start the engine and have it running to make sure is really working well but there was another way to test engine. Another session of work led me to "resolve", al least to have the engine running, problem of a missing fuel pump. I got a fuel pump with compatible pressure and capacity from local car scrapyard (lancia K-2000 payed 10 euros) I just dropped that pump in K100 tank, some fuel hose and a gasoline filter, made electrical connections and here it is an emergency fuel system to test the engine... or to fix a troubled pump on roadside.
Another session of work led me to discover cracked fuel lines running form tank to pressure valve to fuel injectors. I think those rubber lines where OEM that is, 25 years old so no wonder those lines where dripping gasoline as soon as the emergency pump put fuel system under pressure. A local car parts supplier gave me a double walled rubber fuel line tested to 12bar of pressure and green gasoline (as we call it here in italy, that is unleaded fuel but full of very aggressive aromatics) After removing airbox and related parts I was able to replace fuel lines then checked again circuits for fuel leakage... this time fuel system seemed okay and seemed time to crank the engine and try to have it running this time. Now I remember that before taking care of fuel system I resolved another problem that is battery and battery support being this corroded by previous leaking battery. A metallic brush, sandpaper and a file got rid of heavy oxidation but unfortunately a corner of this support gone in a cloud of white dust... well it is a small portion and at least for the moment was okay to support a battery taken from one of my Guzzis. That battery 12v 30Ah fits perfectly being only different for breather hose standing opposite side. Ok then crank the engine! neutral, turn key, pump is working, push starter button and let it turn. Well engine is turning starter motor works well but no sign of life... after 7 years of sleep it is a little difficult to awake immediately so try again... and again... and again... uhmmm... let's see, sparks are there but no smell of gasoline from exhaust. I knew for sure gasoline was reaching fuel injectors but not sure if fuel injectors where squirting. Attaching a multimeter showed me electrical power was there so this means injectors somehow didn't squirt despite being driven by jectronic. I had to pull down all injectors and related components but this part of the story will be next time then I will tell you about my FFIR
bye for now

Grazie signore,

This is a very nice report on how and when to start spending money to restore the old lady. Using an old car fuel pump immersed in the tank is a wise idea as Restoration can be costly and you have to be sure that you can stretch your budget to replace everything needed.
We are impatiently waiting for your next report.

Ciao,

Hi Flatfour,
The injectors are powered with +12v olts when the ignition is one but the control unit sends a train of earth pulses to fire them which is kind of opposite to what one would expect.If you are not getting a train of earth pulses whilst the starter is cranking then you won't get fuel to squirt out regardless of the +12 volts being at the injector terminals. Sometimes the injectors are blocked by deposits.
Regards,
K-BIKE

flatfour, I also had fuel pressure, and power to the injectors, and no fuel into the engine. It turned out my injectors had been sealed shut by gum and varnish from the old fuel. Hopeless, so I had to replace them, they could not be cleaned. This may be your problem as well. If you pull off the fuel rail with the injectors attached, and then turn over the motor, you can see if they are squirting. Then you know for sure. You seem to be good with 'workarounds'. The BMW injectors were also used by many other vehicles including 4 and 6 cylinder Fords. The Bosch part number is 205150710. Maybe you can find a set at the auto wreckers to get yourself running.

@K-bike thanks for that info, I was suprised at the beginning having in one pin a fixed +12,9v while the other not grounded bosch trik here.

hello
I'm back to tell another episode of my adventure. This part was in october when I was still hoping to ride the bike before real cold weather.
As I said before injectors became my concern so I planned to take apart fuel rail and injectors but first trouble arose when I realized that injectors where surrounded in road dirt so first I had to clean carefully injectors surroundings with solvent and compressed air then and then only pull out injectors. Manuals said just pull fuel rail and injectors will follow but in my case I found that pulling wasn't enough. Using levers and WD40 gave me as result fuel rail coming off from injectors but injectors where still sitting in their place. I flooded injectors surroundings with WD40 and following day by using pliers and a combination of pulling and turning and twisting (I felt like a dentist here) I was able to release injectors form their location, later I discovered that O-rings where hard like stones and badly scored.
Now with injectors on the bench I could test them, ohmmeter said they where okay (they should be 16 ohm If I remember well) then I tried powering them hoping to hear a click that is, needle valve opening but none of them seemed to be working and that explained wery well why engine didn't start.
Ok I got four non-working injectors of course replaceable, maybe not so expensive but what kind of a resurrection could ever be If I simply replace parts I decided to give them a try. I knew that the bike was left unused for years, I found small spot of rust inside fuel rail, injectors are seled that is "no serviceable parts inside", but.... I tought "what an occasion to learn and have fun with those things, If they are broken I'm not going to make any damage and If I can recover them I can save money and get experience"; later I started with higher and higher level of abuse on those injectors. Starting with compressed air to 16bar couldn't resolve... ok it was just a try. Then using WD40 injected right into fuel intake and let it cure for a day but no result not even using more than 12v. I used a bit of calculation here becouse injectors having 16 ohm with 13,5v (when operating) means roughly 850mA of current becoming mechanical energy. I supposed that exerting more mechanical force, that is increasing current, maybe was strong enough to unglue those sticking needles. So I dubled voltage assuming that resulting 1,5A couldn't melt internal windings. Brute force seemed useless here so I changed approach by using a combination of mechanical force and chemical attack. To make it short my successful attempt was using a pan filled with "petrolio lampante" (don't know how to translate that term but it similar to diesel oil just lighter but it's not kerosene) heated to 70C with an electric stove and had injectors immersed in that hot liquid for six hours; it was a wery smelly operation and there was a risk of fire but doing it in an open area shouldn't be to much of a danger. After that operation, injectors where hot and hopefully gums and varnishes less stiky, I connected injectors to an electronic circuit made with "quick and dirty" approach with IR-F1405 mosfet few other components and a function generator adjusted for a square wave sweeping duty cycle from 20 to 80% and frequency 20 to 60hz driving the mosfet. The idea was to simulate jetronic driving and rpm variation so to force those needles to move while immersed in a hot solvent almost like their typical runnig environement. After 30min injectors begun to clickclickclickclick... releasing dark matter while bathing in solvent.
Heat, solvent and mechanical vibration seemed successful here and, you may not imagine that, FFIR stands for Flatfour-Fuel-Injector-Resurrector . Another session of work was dedicated to fuel rail having it carefully cleaned then I was able to see those injectors squirting gasoline. They may not be perfect since almost surely they already have 85000km of work but my main goal here was to have a running engine altough not perfect.
Hey club_c if you still have those seized injectors try my method and if you don't have a function generator I belive that a simple 20VA transformer with 12v exit then half rectified to have a pulsing DC voltage could be enough to treat those injectors. Let us know.
Bye

Well done flatfour!

"If they are broken I'm not going to make any damage and If I can recover them I can save money and get experience"

Exactly what I do when things don't work.

Flatfour,

This is a brilliant idea!
Normally, people try to clean the injectors with external ultrasonic waves which is a vibration at high frequency. You went further by softening the residues and applying it internally.
I just have one word (or few...)
As most of us are 'Jack of all trades' and 'master of none' (This is an expression here in Canada -and maybe somewhere else- saying that we know a bit of everything but don't master anything), could you please give us as simple schematic of the circuit with the IR-F1405 mosfet?
I think that anybody able to save a set of injectors with your solution should send you a nice bottle of Chianti.
I am anxiously waiting for your next report.
Well done!

Bert

flatfour wrote: Hey club_c if you still have those seized injectors try my method and if you don't have a function generator I belive that a simple 20VA transformer with 12v exit then half rectified to have a pulsing DC voltage could be enough to treat those injectors. Let us know.
Bye

flatfour, your words look like English, but I have no idea what that means! Can anyone translate electronics-ese for me? I get the idea of a hot solvent bath and a current to work the injectors, but the transformer side of it might as well be written in Italian.

hmmm...nice work.

My method was to connect to a vacuum pump and dip the injector in a commercial fuel additive in an ultrasound cleaner.
12V is pulsed by hand (push non latching switch).

I will now repeat the above but in a hot solvent bath.

Warning about organic solvents: they are mostly liquids with low boiling points, so careful around 12V sparks and fire!

Thank you... good idea

BTW use of vacuum on a cold cleaner will also tell you if the injector leaks.

What a brilliant idea never seen that before on the net Flatfour you have invented something very impressive. I would also like to see the circuit you designed. For club_c what flatfour wrote was perfect but technical English you need a transformer with at least a 20VA rating with 12 volts output so to translate into simple English volts times amps = 20. Given we want 12 volts the equation becomes 12V times A=20VA so about 1.7 amps. So look for a transformer that has a 12 volt output and can supply about 1.7 amps on the output. Now the clever bit is to take the 12 volts output and put a silicon diode of for safety a 3 Amp rating with a voltage rating of around 100 peak inverse volts. You may see them rated 100PIV or simply 100 volt rated. Higher rated is OK.
The circuit is shown http://www.google.co.nz/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/thumb/9/9b/Halfwave.rectifier.en.png/500px-Halfwave.rectifier.en.png&imgrefurl=http://en.wikipedia.org/wiki/Rectifier&h=111&w=500&sz=17&tbnid=_4mUeVzX0zrlHM:&tbnh=29&tbnw=130&prev=/images%3Fq%3Dhalf%2Bwave%2Brectification&zoom=1&q=half+wave+rectification&usg=__RPbCZ17qkxcO0HnA6UDFFe7tvUU=&sa=X&ei=Omr8TKXjHoXmsQPSw9T2DQ&ved=0CCsQ9QEwBA on the image .
What it does is give a pulsing supply to the injector so that whilst it is being subjected to solvent and opening on and off 25 times a second if you have 50Hz mains or 30 times a second if you have 60Hz mains.
Regards,
K-BIKE

K-BIKE wrote:What a brilliant idea never seen that before on the net Flatfour you have invented something very impressive. I would also like to see the circuit you designed. For club_c what flatfour wrote was perfect but technical English you need a transformer with at least a 20VA rating with 12 volts output so to translate into simple English volts times amps = 20. Given we want 12 volts the equation becomes 12V times A=20VA so about 1.7 amps. So look for a transformer that has a 12 volt output and can supply about 1.7 amps on the output. Now the clever bit is to take the 12 volts output and put a silicon diode of for safety a 3 Amp rating with a voltage rating of around 100 peak inverse volts. You may see them rated 100PIV or simply 100 volt rated. Higher rated is OK....
K-BIKE

Correct me if I am wrong, but if you get a simple, cheap battery charger you will get exactly what you have described,. a transformer in a box with a diode. If not you can get a cheap battery charger open it, by pass any electronics and insert a diode as described by K-B.

K-BIKE wrote:
What it does is give a pulsing supply to the injector so that whilst it is being subjected to solvent and opening on and off 25 times a second if you have 50Hz mains or 30 times a second if you have 60Hz mains.
K-BIKE

On the bike, the injectors are energized once for each rotation of the crankshaft.
Do you realize that it is the equivalent of having the engine running at 1,800 rpm for 60Hz or 1,500 rpm for 50Hz main?
In order to accomplish this on the bike, you would need a super turbo starter

All I'm reading is blah, blah, blah...

What I want to see is that someone can describe what we need to do to build one of these things in twenty-five words or less (and a million photos).

Build it and people will buy it. But it must come in assorted colours...and have a BMW sticker on it somewhere (so you can charge more for it!).

Simple words?
Try to touch the injector with an electrical wire 1,800 times per min. This circuit is doing this for you.
What do you need to build it? a 12v transformer, a diode and a BMW sticker. (9 words including the BMW sticker)

here is my attempt:
The AC current goes +240V to -240V 50 times per second. the transformer drops this to +12V and -12V per second.
The diode (in line) only allows only +12V component through and blocks -12v. So you only get +ve pulses which trigger injectors. It is like having the L-jetronic brain running at 1800 times / sec as Bert said.

To build it all you need is a transformer, a diode (from Jaycar) and clips to connect the thing.

So, solder the diode to one of the 12v leads (correct orientation is important) and connect to the injector. That is it.

Alternative is to put a switch in line and press it a few times from time to time to pulse the injector. If the gum is soft enough the injector will fire.

Hey Flatfour,

Are you there?

After your last report and one of the brightness idea found on this forum (about cleaning the injectors), we are all anxiously waiting for your next report. We want to know all your tricks! Pleeeaaassse, don't let us die ignorant!

cheers,

bert

wow!
As I can see my FFIR developed some interest and discussion her but as I said my goal was to have a working set of fuel injector to have my engine running. Maybe it's a little bit in excess believe that FFIR cleans injectors but at least *can* recover to an acceptable level of efficency one or more stuck injector. As in my case I started with four "paperweight" to end up with working injectors at least good enough to start the engine and have it running. Maybe I'm far from having now perfect injectors but at least they are working, so let's me say that those lucky people here having ready to use K100 bike (being my bike almost dismantled) may test FFIR to "clean" their injectors and see if improvements will appear. I promise I will give schematics for those willing to experiment but I'm confident those having a function generator at hand and know how to use it, can surely create a small circuit with a mosfet to drive their injectors, while others can use a simplier approach with transformer and diode (you got it perfectly Ned)... and of course a BMW sticker at hand otherwise thing will not work.
Back to my resurrection now.
After having adapted an automotive fuel pump, replaced fuel lines and resurrected back to life those injectors, changed motor oil and filter, one great day I was able to start engine. Key on, neutral, switch, and then starter button pushed... after few tries first sign of comustion came off exhaust, just a little bit of patience and...here it goes! smoke of half combusted oil becoming in seconds a thick cloud of burned oil obuscating sight of near and far objects... men! what a smoke here, better turn off and let disperse this cloud . Later after several smoking sessions the engine ceased to resemble an old steam engine and was even able to run smoothly until radiator fan turned on. No oil leaks, no water leaks distribution seemed okay as well as transmission and clutch, alternator charges battery. Ok engine seems fine but there is a slow response to throttle and a rattling noise coming from the alternator. As I already knew alternator rubber damper must be really worn out or broken, while throttle response will be checked again with right fuel pump and a little more maintenance. After that glorious day I was less worried about engine so I could take care of other things like brakes, steering, forks and so on.
Next time I will tell you about a trick I learned form Emmet Brown using flux compression...
bye now

Wondering, what is the North American equivilent of "petrolio lampante (don't know how to translate that term but it similar to diesel oil just lighter but it's not kerosene)" ??? I'd like to try this while I'm off over the holidays. I'm thinking I'll heat the liquid on my barbeque side burner, using a thermometer to monitor the temp. Anyone?

Playing with fire again?
In stead of using an open flame, I would use something like the heating element of an old electric hot water tank. You could use thermostat to monitor and regulate the temperature.

yes was actually considering going to a thrift store to find a hot plate. Any ideas on the product to soak in?

The nearest equivalent to petrolio lampante would be white spirit.
Regards,
K-BIKE

Thanks K-BIKE, but still drawing a blank...

For your information, White spirit (or mineral spirit) is sold under the name of Varsol in Canada.

Thanks Bert. Would common automotive shop solvent be the same? Or paint thinner?

Lacquer thinner used to be the solvent used for cleaning injectors you just need to be very careful as it is a lot more inflammable than white spirit but it is a more effective solvent. I think if I had a dry badly gummed injector I would use the penetrating oil mix described elsewhere of ATF and Acetone or I would use PB Blaster and let it soak overnight with the stuff inside the injector and around the outside of the injector pintles. Then wire it up and give it a buzz.
Regards,
K-BIKE

fantastic write up ...thanks .....love the humor

hello folks

please excuse me for having disappeared but I've been very busy with my healt lately. I'm recovering at home now after many weeks of hospital where I found myself abrouptely , and being home means return to usual activities, being posting on forums one of those. I can't wait until I will be able to work on that BMW again to make sure will be running in time to profit of better climate (FYI I'm not a "summer only" motorcyclist but, hey!, I'm old enough to feel cold climate being nasty on my poor bones )

bye

Glad to see you back Flatfour.
Sorry to hear about your health problem. I wish you a speedy recovery.
Your first few posts generated a lot of positive discussion. We are anxious to read more about your K100 resurrection.

Cheers

Bert

Hi Flatfour,

Glad to hear you are on the mend, have been enjoing your reports and look forward to the next instalment.

BIG D

Welcome back.

Take it easy and get yourself well again.

keep well .....hope you get to ride real SOON

Hey Flatfour,
Really enjoyed reading your posts and the inventive solutions to the challenges of bringing back one of the ol girls. Hope you have a speedy recovery and are able to continue work on your bike!

hello bikers
sorry for being absent for a while but now I am almost in shape to the point I was able three weeks ago to think about motorcycles and my BMW of course. Just to explain a little, months ago a car hit me while i was walking and, as you can imagine, it was bad. Two months of hospital with some broken bones and other problems followed by other weeks of therapy to regain flexibility and a little strenght gave me the chance to return home where with patience and time led me to the point I am now. Not long ago I was able to ride a bicycle reassuring me about balance but I still lack of strenght in my arms legs and hands but now it is just a matter of time and work. Despite my situation I was able to work on my BMW a little time a day and now my last discovery was about a worn out damper right in the intermediate axle so my BMW resurrection will take longer but I'm not in a hurry. Meanwhile I have to regain some strenght before thinking of riding a motorcycle, lukily I have lighter motorcyles than BMW k100

bye now

It's good therapy to work on your bike. I'm glad to hear that things are looking up.
Keep at the exercises and you'll be back on the K in next to no time.

I see that you have some tasty bikes in your collection. Enjoy!

cheers flatfour ....good to hear that things are looking better for you... what a turn of events....sighs ...

everyday we are alive and kicking is a bonus mate .....

That is really bad luck, keep at the exercises and fight yourself back to health. We are all supporting you with positive thoughts.
Regards,
K-BIKE

Flat four, bless you on your recovery. I look forward to reading about your ingenuity on bringing the girl back t o life .

Thank you.
Mikey

Speedy recovery flat four , just a note on the white spirit- solvent debate how about brake cleaner ? I use it for every thing from degreasing to graffiti removal.
Just keep it away from painted items ......... yes its removing the color from a colorbond fence . Brake cleaner appears to be stronger ( if thats the correct wording ) than thinners
just a thought