dreaded sprag cluch issue.  If you dont know what this is then search the forums.  This is my super cheap fix and done in about 40 minutes includes 20 minutes with flusihin oil and engine running..

parts needed
12mm drill
1/4 bsp plug with o ring (see below for the item i bought)
http://www.ebay.co.uk/itm/111268478093?var=410275065095&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
flushing oil
http://www.ebay.co.uk/itm/231095282248?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
two oil filters
http://www.ebay.co.uk/itm/270776992221?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

drill hole as per pictures. 
move gear through the window to align the flushing hole on the sparag clutch
you should see the hole as in the second picture.
spray into hole with wd-40
and it now works.

i then ran flushing oil in the engine until the fan turned on.
changed oil and no problems.

cap the hole with the bsp plug. no need to thread it.

rotate images 90 CW fro the correct view

This is not a bad idea, but the hole has to be drilled when the engine is open (I wouldn't want to have the shavings in the engine) The engine's drain plug has a magnet, but it doesn't collect aluminum.

My bro and few other people have flushed the engine with diesel fuel and apparently it doesn't hurt and solve the sprag clutch problem.

Hi CF - how did you flush it?

Hi crazy frog,  can you supply any details on the procedure used please, was it simply fill to overflowing with diesel and allow to sit?  is the sprague situated below the filler level? was the starter engaged at any point of the soak?
im not keen on drilling a hole either , for the same reason you stated .

The easiest way is just to use Diesel oil in your next oil change, it has detergents in it that clean up lots of muck. I just rode mine like normal for 1500 ks or so and changed the oil back to 10/40. Be prepared for the horrible looking oil that comes out. My Sprag hasn't given me any more trouble for a couple of years now, maybe I should do it again as I've just put the Mokkers on myself.

Diesel engine oil and not diesel fuel oil is the go. As RT said it cleans the crud out of the sprag clutch and every where else, mind the state of most diesels insied it seems that it needs even more cleaning power.

yes i see the benefit of preventative maintenance, its remediation im asking for,
one of my shed bikes has a gummed up sprag (sprague?) , starter whines but no engagement ,  it doesnt get road time and i dont fancy push starting it . will diesel do it ?

only if you run the motor beano

the Sprague clutch is high up ....so needs some splashing about to get oil up there ??

The Diesel oil is a good way to go..as Charlie says as long as you can ride it.. After riding a couple thousand with the diesel oil it was still intermittent so I went this way Clean Your Sprag. I have had no problems since.

Only if you can get very old fashioned diesel oil from the '80s. If you use the 5W30 diesel oil that is used in modern diesels then it contains no more detergents than any other petrol oil. I would not put it in my K though, I'll stick to 5W40 petrol oil. I am sure that if diesel oil was better for the K then BMW would have said so 30 years ago.
It's funny how these snake oil stories go around the internet and get more and more believed.

Funny how this snake oil works. I did it with my K1100 when the sprag started to not work sometimes and it has not done it again and I did it with the car when the hydraulic lifters started to get noisy first thing in the morning and it worked there.
Just because you don't believe it works does not mean it is snake oil.

RicK G wrote:Funny how this snake oil works. I did it with my K1100 when the sprag started to not work sometimes and it has not done it again and I did it with the car when the hydraulic lifters started to get noisy first thing in the morning and it worked there.
Just because you don't believe it works does not mean it is snake oil.

Rick, the trouble is that I am an engineer and will not take the odd person saying that it worked as evidence. For your case a change of oil to a decent petrol oil may have done the same, so a one off case is not evidence. If you could use a one off case as evidence then smoking does not kill as my grandfather smoked till he was 95!
Over here where 80% of cars are diesels you will find that many of them use the same oil as a petrol anyway.
It is not just that I don't believe it but I would expect most oil experts and motorcycle manufacturers would not recommend it either. But at the end of the day it is your bike and you can put what you want into the sump, the problem will arise when someone else does it and had a severe engine problem, then the internet will be awash with people saying that it has wrecked engines all over the place.
The wise thing for anyone to do is not to believe what you read on the web, but if you want to try something then phone your BMW dealer and ask him if it is a good idea.

Whatever you want.
I will also say that this HAS been working for many people for a long time and here on this forum and others I have seen evidence of people saying it has worked so why be so damn sceptical and poo hoo what many KNOW is working
Like I said just because you don't believe it does NOT mean it does not work.
But you are quite free to believe the earth is flat if you wish to believe it.

Whats the collective opinion on diesel loosening the crap in the starter clutch ?

it'll need to be filled to overflowing via the engine breather .
I'm entertaining doing the experiment, in the name of science and laziness.
Any drawbacks or considerations ?

You wont stand a chance of it working to any real extent without being able to run it. It needs to be worked around the engine when its hot then it has its best chance. It's like putting all the clothes in the washing machine with water and detergent and not running it.

To trow another spanner in the non-discussion :-)

Some oils have the detergent/cleaning indications mentioned for both Petrol and Diesel engines on the can. IIRC Castrol GTX is 3A/4B and should be suitable in both type of engines. You need to look further than just Petrol or Diesel ;-)

Hi there, I don't use diesel but when my k´s sprag failed, I learned, on the internet, about the gumming problem and the flushing solution.
Also learned that, some times, by reverse turning the engine, the sprag will let go and you can start the engine, as was in my case.
I think that if you need to jump start, that's easier than dismantling.
For the flushing I used a commercial flushing additive, which is added to the old oil just before a change, then run the engine at idle for 5 or ten minutes, and drain it, preferable when still hot.
This was some 6 years ago, since then I flush the engine every other oil change and have had no issues. I´m also flushing the car´s engines and the lifter noises are gone.
I would say that this adds 3 more cases to Rick´s account.
Best regards
JAP

http://www.lubricants.total.com/pro/contact-et-faq/faq.html

As I said earlier if you don't believe a company like Total in the link above, then ask your BMW dealer.

The only thing a BMW dealer does well is take money from you
If you take your bike (any bike) to a dealer for servicing, even within the warranty period then you are seriously neglecting the bike.
I have worked for 3 of the 4 major Japanese manufacturers and there is absolutely no reason that I would expect BMW to be any different.
As for what Total said on the page you linked to Heaps of Waffle and no ice-cream and make up your own mind.
I am not disputing that the oils are different and they would need to be, they are designed by experts for different applications however that does not alter the fact that using the diesel lubricating oil does in many cases help to get the crap out of the sprag clutch and get it working and the bike rideable.
Using this method may not be the be all and end all to sprag clutches but it is worth a try so don't knock it
I intend to finish this by asking if you have ever put your head in a bucket of shit. Well don't knock it till you try it.

Have used Comma, a subsidiary of Esso I believe, Super 15w/40 and Premium Plus 15w/40 advanced mineral oil for the last 25 years in R80's and now my K with no problem. Both universal oils for petrol and turbo diesel. With the greatest respect, I think there is a lot of twaddle talked about oil, but If it makes you sleep sounder at night, use what you like. John

RicK G wrote:Diesel engine oil and not diesel fuel oil is the go. As RT said it cleans the crud out of the sprag clutch and every where else, mind the state of most diesels insied it seems that it needs even more cleaning power.

I wanted to reply this morning, but the site was slow (Did anybody noticed it?).
What my bro and other people used was diesel fuel
They let the bike ran with diesel fuel for few minutes then flushed the engine twice with new oil and filter.

As a note, if you want to start your bike by pushing it, remember to push the starter button when you engage the clutch. This will start the fuel pump and put the computers in starting mode.

CF

Crazy Frog wrote:

RicK G wrote:Diesel engine oil and not diesel fuel oil is the go. As RT said it cleans the crud out of the sprag clutch and every where else, mind the state of most diesels insied it seems that it needs even more cleaning power.

I wanted to reply this morning, but the site was slow (Did anybody noticed it?).
What my bro and other people used was diesel fuel
They let the bike ran with diesel fuel for few minutes then flushed the engine twice with new oil and filter.

As a note, if you want to start your bike by pushing it, remember to push the starter button when you engage the clutch. This will start the fuel pump and put the computers in starting mode.

CF

Yes I found site was at snail pace yesterday for a while. As for bump (push) starting the K, I have never needed to push the starter when dropping the clutch. A quick prod beforehand to pressurise the system, and it will fire up easily.

The fuel pump also starts as soon as the ignition ECU receives a signal from the hall sensors......i.e. when letting the clutch lever out.

Inge K. wrote:The fuel pump also starts as soon as the ignition ECU receives a signal from the hall sensors......i.e. when letting the clutch lever out.

..unless you have a dodgy in or out connection at the ECU.......?

Mork calling Orson , come in Orson . . 
after testing all the various aforementioned methods of convincing the starter to engage , shy of surgery (although the hole could be drilled with some positive pressure -nitrogen- applied to force swarth out) ive filled the sump with diesel for the science of it .
the bike is an ebay five hundred dollar bargain bought for parts but too good to scrap so it sits complete, its starter was hit and miss to begin with and after a six month sit without starting fails to engage at all.
the engine took seventeen and a half litres approx. of diesel ,  after filling to oil filler level , i used a long funnel fitted into the engine top breather hose, the last two litrres being hardest with much slow rocking back and forth to allow diesel to go in and air to go out . 
some fuel leaks past the rings and out the plug holes and also into the exhaust headers at a rate of a drop per second , i will call this the flushing action ! i had twenty litres in total and will keep the funnel full until it is all leaked through , trying the starter at my impatient intervalls and report any changes . 
nanu nanu

Holy crap!

When (if) you try to start it, please, please, please make sure you video it! This I gotta see!

As mentioned in the previous posts, the idea is to replace your oil with high detergent diesel oil (DO) and  run the engine; some folk say for a few hours, while others say days and there are even people who use DO all the time.
Depending on who is telling the story (and I acknowledge everyone's opinion), the DO "scrubs/removes/shifts/cleans" the engine and the sprag clutch will again work as intended.

My opinion only.

Neil.

i wont be trying to start it mate ,  my hope is the starter will catch after a bath of a week or a month ,  without combustion -plugs out ,even hit n miss , like it did before ,  then it can run the diesel oil .

far out. interesting development. never heard of such a thing

out of curiosity, why not just take the bell housing off and clean it out. Its not that big a job for a bike thats just sitting anyway. You can put a new seal in too.

just to see if it works .

beanoldboy wrote:just to see if it works .

sweeeeet. Look forward to seeing what happens

My 86 k75 has 231,000kms and I ran with Spectro Gold, then Esso Formula 1 before throwing my hands up 4000 Km's ago and can say using Shell Rotella diesel oil has completely freed my sprague. The great thing is also Rotella is also about 1/3 to 1/2 the cost of other oils. I also followed advise to throw Rislone in with my previous oils but the sticking would gradually come back about 3500 Km's after a change.

I am really glad I switched to diesel oil

Sunny

VERY interesting post. I have been googling for HOURS over several days. Also I have talked to 3 mechanics and several other BMW intusiasts.

I ride a K1100RS from 1992 with a little over 100.000 km. I took it out a month ago (cold here in Denmark) with out changing the oil.

Suddenly one day the starter didn't connect with the sprague clutch. The starter spinned VERY fast/fine. After a couple of backing up in 2. gear and releasing the clutch I could start again.

I got the advice "take a long ride" (I had only driven to/from work 14 km each way) and change the oil. I did both things. Two weeks later same problem. It took 6-7 back up's before the starter engaged. After this I didn't dare to ride anywhere.

After much research I ended here (VERY fine post, thank you), however I'm not drilling any holes in my bike and I don't really want to put diesel in my engine.

I got this advice from the largest BMW shop here in SMALL Denmark:

Put a "engine cleaning solvent" (sorry no idea which/what yet but will find out soon) into the engine (into the oil that is already there). About 200-400 ml. Run the bike for 30 minutes (NOT ride it). After this change oil and filter.

What do you think?

A new Sprague Clutch will cost about $500 and the shop (two different) claims it will be at least one day's work (8 hours) and they charge over $100 an hour. So I'm looking for any cheaper solution.

Danish biker wrote:

I got this advice from the largest BMW shop here in SMALL Denmark:

Put a "engine cleaning solvent" (sorry no idea which/what yet but will find out soon) into the engine (into the oil that is already there). About 200-400 ml. Run the bike for 30 minutes (NOT ride it). After this change oil and filter.

What do you think?

My K100 behaved that way too in similarly cold weather.  I used Risolone as a additive  and rode 200 Km then changed oil and filter. A good synthetic oil has detergents to help clean residue and prevent future problems. I use 0W-40 Mobil 1 and the bike starts much easier in cold weather to boot !

Danish biker wrote:A new Sprague Clutch will cost about $500 and the shop (two different) claims it will be at least one day's work (8 hours) and they charge over $100 an hour. So I'm looking for any cheaper solution.

Not impossible, but it is unlikely the sprag/spragg/sprague (choose your favourite spelling) clutch will need replacing, just cleaning sticky deposits out.
Whether you do it yourself or pay someone else to remove and clean it, it's expensive in time or money.

Oil additive or different oil is the way to go as a starting point, dismantling being the last resort. 

Bill

I tried an engine flush additive on mine, then I tried diesel oil. Neither worked effectively. Eventually I had to pull it apart for an output shaft change so I dismantled the starter clutch at the same time. It looked quite clean when I pulled it out but it was surprising how much sludge came out when I cleaned it. And those itty bitty springs are a pain to put back in with fat fingers. I run it on diesel oil now to keep things clean, but I read somewhere else on this forum that Mobil 1 is the way to go so I'll try that next oil change.

Danish biker wrote:
After much research I ended here (VERY fine post, thank you), however I'm not drilling any holes in my bike and I don't really want to put diesel in my engine.

No. Don't put diesel fuel in your engine. As Rockman says above, diesel oil is ok. It's a high detergent oil and does a reasonable job of cleaning sludge out of the engine. So too will synthetic oils as they're also detergent. But I think this may only be a solution if the amount of sludge build-up is light.

A good reason to use synthetic or at least a quality oil instead of "anything that's slipery" as I've heard suggested.

Had problems with the sprag in my K100RS.  Pulled the oil out and replaced it with cheap 10W30 and a 16oz. can of Seafoam.  Did a back spin in 3rd to get the starter to work and took it for an easy 20 mile ride followed by an oil change.  Absolutely no problems in the 600+ miles since.

I too am using Shell Rotella T6 full synthetic 5W40 in all my bricks now.  The additive package is for diesels, but I figure that since diesels live a harder life what's to lose by using it in a gas engine.  THe detergent package in diesel grade engine oil is attractive, especially with regard to the sprag.  At less than $23 a gallon the Rotella looks like a pretty good deal.

Put me down for diesel oil as well. Oil is a funny thing. I used mineral oil for years, then switched to synthetic. Now, my sprag will gum up if I use mineral. It has given me trouble once on synthetic, and the way I fixed it last time was to run diesel oil. I don't know if all Ks are the same, but mine push starts easily.

WoodyAUK75 wrote:Oil is a funny thing.

Looks that way. I'm still using pure dinosaur pee and I've had no trouble in four (five?) years. Possibly because LFB gets used at least five days a week for fifty miles.

have to agree dai ...nothing like regular riding to keep things moving properly
but diesel oil  works well ...once in every 4 changes for this little black duck

"...once in every 4 changes for this little black duck"

Good idea there Charlie!

Gentlemen (and ladies if any).

I went shopping today:

Sorry I'm continuing in two post but putting in pictures was a challenge 

Any way I'll run the bike for 30 minutes with the cleaning liquid in the old oil and then change oil and oil filter.

I hear you regarding diesel oil I'm just not quit there yet. Maybe thinking: "If it works so great why not entirely skip oil for gasoline engines and simply use diesel oil?"  Oh well I might get around but first I'll try above mentioned.

Now excuse my ignorance but any thing I should be aware of when it comes to changing the oil filter? I have been told it is placed up under the engine (can't be seen) close to the nut you take off to drain the oil.

Any pictures will be apreseated and so will advice (tricks etc.). I'm assuming I'll probably need a special "unscrew the filter" tool?

My experience, FWIW:

When I got my K 15 years ago I used it for commuting, 80-100 miles per day.  Never had the sprague clutch problem.  For a variety of reasons, I didn't ride the bike for about 7 years.  When I resurrected it, I took it to a local independent motorcycle guy who is knowledgeable about BMWs for a basic check-over, to change out fluids, etc. Mostly wanted a trained second set of eyes before going full speed ahead on a bike that had been sitting for so long.  Shortly after that, I began having the dreaded sprague clutch problem.  Whether the mechanic put the "wrong" oil in it, or whether it was due to the fact that I was now commuting only 1 mile to work and not much more, or because things had gummed up due to sitting for years, or a combination, I don't know.  

After reading up about it on the forum, I put Shell Rotella diesel oil in the crankcase.  Had to push (bump) start it.  Rode the bike for 15-20 miles and never had the sprague problem again after that first ride.  I used that oil for about 200 miles.  I changed it because I had an annoying leak from my oil filter cover that I needed to fix (if not for that, I would have used the Rotella until the next regular oil change).  After fixing my leak, I put the regular BMW brand oil in and haven't had a problem since (probably won't use that again because it is ridiculously expensive).  I've also taken the "precaution" of trying to make sure every ride is at least 15 minutes and involves getting to full speed and RPMs to ensure that the bike gets to full operating temperature.  

So, I'm a +1 for the Rotella (and longer rides).  However, YMMV.

Dai wrote:

WoodyAUK75 wrote:Oil is a funny thing.

Looks that way. I'm still using pure dinosaur pee and I've had no trouble in four (five?) years. Possibly because LFB gets used at least five days a week for fifty miles.

No argument here Dai. The thing is, mine was running fine on dino as well, but then one year I got a good deal on some synthetic so I used it. Next change, back to dino, and sprag problems. It could be a coincidence, but the K has a personality and I think it likes synthetic.

Danish biker wrote:Gentlemen (and ladies if any).

I went shopping today:

Specifically formulated motorcycle oils like this above are designed for wet clutches which we don't have in our Ks. All we need is a good quality engine oil. I don't think it will hurt using it but there are probably better and cheaper oil choices imo.

I've not used diesel oil but I'd guess most of them are compatible with petrol engines. A lot of oils on the shelf these days indicate they are suitable for both petrol and diesel. As long as its a good quality detergent oil and its changed at regular intervals you won't go wrong.

The important thing to understand is that oil is used to keep metal parts apart and modern oils do that MUCH better than older style oils. The K engine was fairly advanced for its time and BMW specified the latest synthetic oil technology available back then.
This post by K-BIKE is a worthwhile read.

Quite some while ago, after dumping diesel dinosaur pee in LFB (because that was all that was available at the time and I needed oil desperately), I asked an army-trained vehicle mechanic (who is also a biker/triker) if it would do any damage. His response - which bears out everything said above - was 'No. Diesel engine oil is designed for tougher environments than petrol engine oil and, if anything, will clean the sh!t out of your engine'.

The only potential mark against use of diesel oils in a petrol engine that I have been able to dig up, is the fact that some diesel engine oils might have a formulation that will result in the catalytic converter being 'poisoned' (if you have one). Obviously doesn't apply to our vintage Ks

Dai wrote:Quite some while ago, after dumping diesel dinosaur pee in LFB (because that was all that was available at the time and I needed oil desperately), I asked an army-trained vehicle mechanic (who is also a biker/triker) if it would do any damage. His response - which bears out everything said above - was 'No. Diesel engine oil is designed for tougher environments than petrol engine oil and, if anything, will clean the sh!t out of your engine'.

Pushing 33 years as a infantry officer I can only say you are right. I got the same advice from some of all the army mechanics I've served with both in land and in missions throughout the world. How ever I'll try the cleaning liquid for 30 minutes, in a hot engine first. And then the Castrol I bought. If it doesn't help I'll probably use diesel fuel 

Any last remarks before I try the trick tomorrow?

Danish biker wrote:

Dai wrote:Quite some while ago, after dumping diesel dinosaur pee in LFB (because that was all that was available at the time and I needed oil desperately), I asked an army-trained vehicle mechanic (who is also a biker/triker) if it would do any damage. His response - which bears out everything said above - was 'No. Diesel engine oil is designed for tougher environments than petrol engine oil and, if anything, will clean the sh!t out of your engine'.

Pushing 33 years as a infantry officer I can only say you are right. I got the same advice from some of all the army mechanics I've served with both in land and in missions throughout the world. How ever I'll try the cleaning liquid for 30 minutes, in a hot engine first. And then the Castrol I bought. If it doesn't help I'll probably use diesel fuel 

Any last remarks before I try the trick tomorrow?

NOT Diesel fuel but lubricating oil designed for use in diesel engines.