I need advice. I’m parked at a dead end with my K1100 RS from 1992.
 
For 3-4 seasons I’ve had sprang clutch problems. Or I thought so. Once or twice a season the starter would not make the sprang clutch engage the engine. The starter would just spin and spin. Since I thought it was a sprang clutch issue I opened the engine and did the famous WD40 job on the sprang clutch 2 to 4 times a season.
 
However in May my engine exploded doing 170 km on the freeway. Needless to say I had to get a “new” engine. This “new” engine was fully serviced, and had just been used for 10.000 km on a K1 (while the owner disassembled the original K1 engine). So the LT engine I have now was fully operational with absolutely no starter problems. The total km is 100.000 on this bike.
 
On my first ride the starter failed twice. But not as it did on the old engine. Now the bike would actually start if I hit the starter a second time.
 
My conclusion was: “Ok it must be my starter since it was the starter from the old engine”. I got a used starter. Disassembled it and cleaned it and installed it. But I still get starter problems.
 
The battery has been checked. The connections have been checked. The generator seems to be charging the battery fine.
 
I’m going to order a complete kit for the starter and have a professional do the job BUT my attention has been brought to the fact that it might be my engine oil.
 
On the old engine where the starter problem was worse I used a full synthetic Castol full synthetic 10w-40. Now I’m using a 10w-40 semi synthetic. How ever a MC mechanic has just told me that my oil might be the cause of the starter failure.


He says my present oil Putoline Sport 4R semi synthetic 4-stroke 10w-40 oil is for a wet clutch. I need a oil for a dry clutch.


He is sending me 5 l 10w-60 oil tomorrow so I’ll change oil and know in a week or two if he was right.


What do you think?

Puzzling...

First off, I have been using full synthetic oil in 5 K bikes for 6 years now and only had one problem with the sprag which was due to using too much Molybdenum assembly paste when doing a cylinder head rebuild.  Once the paste was flushed out of the engine the sprag worked fine.

Second, the only difference between motorcycle wet clutch oil and "regular" motor oil is that the wet clutch oil has additives that enhance the friction between the plates of the clutch.  If anything, I would expect the wet clutch oil to be better for the sprag operation than regular oil.

I find it very odd that you are having sprag issues with two different later vintage K motors.  Wish I could offer a suggestion for a cure beyond a good engine oil flush.

Danish biker wrote:
On my first ride the starter failed twice. But not as it did on the old engine. Now the bike would actually start if I hit the starter a second time.

Are you indicating that you believe this to be a sprag clutch issue or that the starter has a different issue?

Laitch wrote:

Danish biker wrote:
On my first ride the starter failed twice. But not as it did on the old engine. Now the bike would actually start if I hit the starter a second time.

Are you indicating that you believe this to be a sprag clutch issue or that the starter has a different issue?

I’m actually not indicating anything. I’m desperately searching for the cause of my starter not engaging the Sprang clutch enough to make it engaged the engine (or what ever is wrong). All I’m hearing is spinning, and spinning.

My own thought is:

1. Either the starter is bad.

2. It is actually a oil issue (I’ll know this, as mentioned, in a week. As soon as I receive the “new” oil I’ll change oil and filter).

Point-Seven-five wrote:Puzzling...

First off, I have been using full synthetic oil in 5 K bikes for 6 years now and only had one problem with the sprag which was do to using too much Molybdenum assembly paste when doing a cylinder head rebuild.  Once the paste was flushed out of the engine the sprag worked fine.

Second, the only difference between motorcycle wet clutch oil and "regular" motor oil is that the wet clutch oil has additives that enhance the friction between the plates of the clutch.  If anything, I would expect the wet clutch oil to be better for the sprag operation than regular oil.

I find it very odd that you are having sprag issues with two different later vintage K motors.  Wish I could offer a suggestion for a cure beyond a good engine oil flush.

Flushing the engine I did several times with the old engine, but this engine is good to go, so a flush or WD40 job would probably not be the solution.

I’m hoping it actually is the oil (secondary the starter).

I’m just fishing here 

Danish biker wrote:All I’m hearing is spinning, and spinning.

Now I understand. Apparently, your moto is still having sprag clutch issues again.

If the starter sometimes fails to turn the crankshaft reliably but just makes a spinning noise instead, rebuilding the starter is not likely to help. The sprags in the clutch are partially stuck which means either they aren't clean enough to engage no matter how clean the rest of the engine is, or some of the sprags have been damaged. Flushing this engine with a product made for the purpose could help free undamaged, stuck sprags; otherwise, disassembly, cleaning and inspection of the sprag clutch will be necessary.

I am not sure. The “new” engine had absolutely no starter problems with the previous owner. Is has to be something else.

Starter, battery or maybe engine oil.

I am not familiar with the oil you are using.  Does it have Molybdenum additives? 

Sprag problems are normally related to the sprags not rolling out and engaging.  There needs to be a certain amount of friction between the sprags and the outer ring along with freely moving sprags to properly engage the starter action.

Danish biker wrote:The “new” engine had absolutely no starter problems with the previous owner.

There is no problem until there is a problem.

Sometimes a seller says three are no problems when there are. Another possibility, it's worn out if it previously had many more starts than usual, but unlikely I guess. I'll guess it's the oil. I spose 10w60 is OK for Europe. If there's still a problem plain 20w50 car oil would be worth trying. I'll guess there wasn't much sludge on the previous one.

Thin, low friction (slippery) oil sounds good for a car,  but not for a brick with a slipping sprag clutch. Motorbike oil is usually also for the gearbox and for an air cooled engine, which a brick isn't.

I can't see a benefit of spending more for synthetic, but I'm a cheap arse. I use Castrol gtx 20w50, without problems but probably only done 20,000km with a brick. When I first joined a brick forum I thought I'd keep it under my hat using car oil,  for fear of getting my head knocked off. Turns out it's not even controversial and people have been doing it for decades.

One of the great things about bricks, dry clutch and water cooled, like a car, almost unique for a motorbike.

N

daveyson wrote:Sometimes a seller says three are no problems when there are. Another possibility, it's worn out if it previously had many more starts than usual, but unlikely I guess. I'll guess it's the oil. I spose 10w60 is OK for Europe. If there's still a problem plain 20w50 car oil would be worth trying. I'll guess there wasn't much sludge on the previous one.

Thin, low friction (slippery) oil sounds good for a car,  but not for a brick with a slipping sprag clutch. Motorbike oil is usually also for the gearbox and for an air cooled engine, which a brick isn't.

I can't see a benefit of spending more for synthetic, but I'm a cheap arse. I use Castrol gtx 20w50, without problems but probably only done 20,000km with a brick. When I first joined a brick forum I thought I'd keep it under my hat using car oil,  for fear of getting my head knocked off. Turns out it's not even controversial and people have been doing it for decades.

One of the great things about bricks, dry clutch and water cooled, like a car, almost unique for a motorbike.

I’ve heard of K owners using engine oil for diesel cars.

It’s an “old” tractor so it can probably run on mayonnaise 

I do not even know what the difference is between 10w-40 contra 20w-50 or the 10w-60 I’m spending $100 on (including new filter, shipment and 5 liter). I’m desperate so if any one wrote:

“Is your helmet black?”

Me: “Yes!”

Other guy: “Is it a Schubert?”

Me: “Yes!”

Other guy: “Is it a C3?”

Me: “Yes!”

Other guy: “Aaaaaahhhhhh there is you’re problem. That is why your starter doesn’t make the sprang clutch engage the engine. Try a red C4.

Then I would go buy a red C4 

10 is thinner than 20

Diesel engine oil has more detergents for better cleaning. The sprag clutch you looked at, if there was sludge there preventing the sprags from engaging, then diesel engine oil might help in that case. If it was clean the problem might have been the oil used.

daveyson wrote:10 is thinner than 20

Diesel engine oil has more detergents for better cleaning. The sprag clutch you looked at, if there was sludge there preventing the sprags from engaging, then diesel engine oil might help in that case. If it was clean the problem might have been the oil used.

What also puzzles me is the sprang clutch I took out of the engine that exploded, and that had the starter problem for 3-4 years, looks very clean and the roles seem to move easy.

I’m still thinking starter or (if I’m lucky as hell) oil.

And I’m very convinced it’s not the “new” engine. It had new clutch, relevant seals was new. New spark plugs. New oil. New oil filter. 

It was recommended by my dealer and the guy selling it used to work for BMW in Germany. Secondary he is highly spoken of.

I agree with him that the wrong oil was used. It's a safe bet to use an oil recommended by BMW in the riders manual.

daveyson wrote:I agree with him that the wrong oil was used. It's a safe bet to use an oil recommended by BMW in the riders manual.

Have no idea what BMW recommended 28 years go, when my brick left the factory but the Rider’s Handbook doesn’t even mention a 10w-60.

Looking at the temp charge I should use SAE 30 so I’m not in any way wiser.

Have a closer look,  there should be multi grade options. For example my manual for 1985 k100 gives 20W 50 as suitable from -10C to 40C,  I spose that's good for Europe too.

Danish biker wrote:Have no idea what BMW recommended 28 years go, when my brick left the factory but the Rider’s Handbook doesn’t even mention a 10w-60.

That's an idea!

The chart in the handbook is a chart of BMW's recommendations 28 years ago, more or less. The multi-grades lessen wear on the engine when cold starting.

Actually I just need to know what you think about me trying out 10w-60 (when the issue is starter problems)

Danish biker wrote:new spark plugs.

There's your problem...

Point-Seven-five wrote:

Danish biker wrote:new spark plugs.

There's your problem...

Why? My old engine had 9 (or more) year old sparks plugs and here the problem was much more worse then now.

Danish biker wrote:Actually I just need to know what you think about me trying out 10w-60 (when the issue is starter problems)

I'm happy to oblige. I don't think it will make any difference.

Danish biker wrote: It had new clutch, relevant seals was new. New spark plugs. New oil. New oil filter. It was recommended by my dealer and the guy selling it used to work for BMW in Germany. Secondary he is highly spoken of.

Are we at the point here where oil used in an engine recommended by your dealer and purchased from a BMW guy highly spoken of is the wrong oil?  

How much more highly spoken of is the MC mechanic who is recommending the 10W-60? You would seem obligated to go with the opinion of the most high of the highly spoken of, unless you go with magical thinking. That is a viable choice which would indicate going with Point-seven-five's advice to check the spark plugs and I'll add that changing your helmet color might help too.

Thanks a billion. I’ll pour the 5 l 10w-60 down the drain. Buy a red Schubert C4 and put in old spark plugs and be happy for ever

I have 20W50 in my K1100LT since about a month ago.  Up to that I was using 15W40 but its too light in hot weather.

I can get 10W60 as my sons car uses it but at the time of writing the BMW manuals 10W60 didn't exist......

I have manuals from 83 to 97 and not a lot of difference over the timescale and the specified oil is quite basic in modern terms.

Why not look at the spark plugs?    Since they weren't there when the sprag last worked properly.

My experience following threads on sprag problems and with one of my own bikes is that sprag problems are caused by the SPRAG.  Wet clutch/dry clutch motor oil has known no effect, as does the condition of the starter motor as long as it turns when power is applied.

As much as you refuse to accept the fact that you need to go into the sprag, that is the thing you need to do before anything else.

Point-Seven-five wrote:Why not look at the spark plugs?    Since they weren't there when the sprag last worked properly.

My experience following threads on sprag problems and with one of my own bikes is that sprag problems are caused by the SPRAG.  Wet clutch/dry clutch motor oil has known no effect, as does the condition of the starter motor as long as it turns when power is applied.

As much as you refuse to accept the fact that you need to go into the sprag, that is the thing you need to do before anything else.

Sorry if I don’t understand.

The sprang clutch never worked so spark plugs or no spark plugs.

Do you want me to look at my spark plugs (and what will I be looking for?)

Or do you want me to look at my sprang clutch?

Probably me misunderstanding, but it seems as if you are pointing me in two VERY different directions.

So spark plugs or sprang clutch?

If spark plugs why?????

Hi DB, If you have the knowledge remove the Sprag Clutch and clean/inspect it
then you remove all doubt and can move on AS for the oil just use Diesel engine oil with regular changes,remember oil filters need to be changed more than the oil .Just my opinion based on 60 yrs experience

Like point seven five says, additives in your oil might not be suitable, for some reason friction modifiers don't get a mention anymore, maybe because they nearly all have it now. Haven't checked the oils you mentioned.

Like Laitch says a flush might fix it. I'm trying, probably not succeeding, to not sound cynical about the previous owner. For example, don't know if he owned it for ten days or ten years, or if he only used it for short trips,  contributing to sludge. Maybe you mostly do short trips. I know I shouldn't think like this, but looking at a map of Denmark makes me think the only way to go on a long ride there is to go around in circles. I spose you've had it on the autobahn though. I'm not big on touring either, the longest ride I've had is two hours.

Held og Lykke.

Being the grumpy old fart I am, I was frustrated by your denial that the problem was in the sprag. 

You need to face the fact that the sprag is the problem and that at least you need to do a thorough engine flush, and if that doesn't work, you will have to go into the engine to service the sprag itself.

Since you don't know the real history of the engine, you can't assume that it has been serviced properly and that there isn't a lot of sludge in parts like the sprag. 

Have you removed the valve cover from the cylinder head?  A good look inside will give you an idea of how clean the engine is.  Any sludge will be proof that the engine has not had regular oil changes.  Even if it's clean, I would get some good engine cleaner(in the U.S. a product called Seafoam is one of the best) and put it in the crankcase.  Start the engine and go for a ride of at least 50-60 km and change the oil and filter when you get back.  I would use a good heavy duty diesel oil 15W40 for the next year.  Shell Rotella T6 full synthetic is the one I used.  Many motorcycle riders use it successfully in their bikes.

If the flush doesn't work, I would think that there is a problem in the sprag and you wll have to go in and service it.  Sure, it's a nasty job, but it has to be done.  The good news is that it will give you the opportunity to address several other items which should be done on an engine that is almost 30 years old.  Things like replacing the engine rear main seal and o-ring, checking the clutch plates and lubing the clutch splines.

Danish biker wrote:Thanks a billion. I’ll pour the 5 l 10w-60 down the drain. Buy a red Schubert C4 and put in old spark plugs and be happy for ever

You're too generous! Keep 500,000,000 of that billion for future thanks. Enjoy the happiness!

Point-Seven-five wrote:Being the grumpy old fart I am

Makes two of us 

Point-Seven-five wrote:Since you don't know the real history of the engine, you can't assume that it has been serviced properly and that there isn't a lot of sludge in parts like the sprag.  

In my first post I’m sure I wrote the “new” engine had just been riding 10.000 km on a K1, and fully serviced.

The previous owner had a K1 that he had ridden 300.000 km on. He wanted to open the K1 engine to see what it looked like (as mentioned he used to work for BMW in Germany), so while doing this he used the LT engine on his K1.

Since he was recommended by my dealer, that I know personally and also highly spoken of on a national forum, I have absolutely no reason to doubt his words.

When picking up the engine I told him about my sprang clutch problems on my exploded engine and asked him if I should put a new sprang clutch on his engine. It would be easy, since the engine was with out gearbox and transmission. All I would have to do was take of the relative new clutch and “go to work”.

His answer was: “That would be a total waist of your time and money!”

I also asked if I should replace the seal behind the clutch (sorry I do not know the name). I even showed him this seal since it was in my car, along with other parts I had bought in order to change the engine.

He told me that this seal had been changed recently.

Of course he could been a full of BS, but I don’t know why though. The deal had already been made. Even if he, before the deal was made, had said: “You definitely need to replace the sprang clutch!” I would have bought the engine and still would have had a smile on my face.

So all this is why I’m searching for another reason for my starter issue. Hope it makes a little bit of sense?

Most of us if in there are likely to take out the sprag clutch and clean it simply because its so easy at that point. They get crud on them and low miles can be worse for this. Its also more likely if it has been sitting in an unused engine.

I see little option but to go back in there and take it out.

If the N in your oil label stands for nano oil additives (friction reducers) that could be a problem. Reduces friction on smooth metal surfaces without impacting rougher wet clutch surfaces.

Nanu nanu.

92KK 84WW Olaf wrote:Most of us if in there are likely to take out the sprag clutch and clean it simply because its so easy at that point. They get crud on them and low miles can be worse for this. Its also more likely if it has been sitting in an unused engine.

I see little option but to go back in there and take it out.

That would be a winter job if a refurbished starter or the 10w-60 oil doesn’t work miracles.

Danish biker wrote:. . . miracles.  

You have 100% of my support for the success of this strategy. Don't bother thanking me. I'll just take one from 500,000,000 you deposited in my account.

Laitch wrote:You have 100% of my support for the success of this strategy. Don't bother thanking me. I'll just take one from 500,000,000 you deposited in my account.

We both know it won’t work with out a new red Schubert C4 helmet, and that is about $1.200 in these parts of the world.

daveyson wrote:If the N in your oil label stands for nano oil additives (friction reducers) that could be a problem. Reduces friction on smooth metal surfaces without impacting rougher wet clutch surfaces.

Nanu nanu.

It only says: Semi-synthetic 4-stroke engine oil. Contains the revolutionary N-TECH additive system for extremely low wear. Excellent cleaning properties and optimal wet clutch compatibility.

Any way the wet clutch part indicates that it’s not what I need any way.

It's a safe bet N-Tech stands for nano technology, I think that's the problem. Hopefully it's removed with one flush.

Danish biker wrote:We both know it won’t work with out a new red Schubert C4 helmet, and that is about $1.200 in these parts of the world.

That's only a problem with magic. Miracles are colorblind.

daveyson wrote:It's a safe bet N-Tech stands for nano technology, I think that's the problem. Hopefully it's removed with one flush.

I,ll drain the oil (and cry since it’s only been in the bike for 500 km) and change filter and then put in the 10w-60 and see how it goes.

daveyson wrote:It's a safe bet N-Tech stands for nano technology, I think that's the problem. Hopefully it's removed with one flush.

It isn't being removed; it's the replacement for what's in there now.

Laitch wrote:It isn't being removed; it's the replacement for what's in there now.

I hope Daveyson get it. I’m not sure I do. But then again I still have to buy a red helmet 

I’m pretty sure that what ever the present oil is leaving in my engine, when I drain it, will in short time be so diluted that I should be fine.

If not I’ll give the engine a cleaning solvent and change oil and filter once more.

But then again as most of you say: “It’s not my oil that’s the problem!” if I have understood you correct, which of course is not guaranteed.

I just know trying a new oil and refurbishing my starter is lightyears easier then taking out the sprang clutch.

As long as you are changing the oil you should throw a bottle of engine cleaner or a half liter of diesel fuel in the old oil and go for a long ride before you drain it.

Point-Seven-five wrote:As long as you are changing the oil you should throw a bottle of engine cleaner or a half liter of diesel fuel in the old oil and go for a long ride before you drain it.

Yes I understand this is the general suggestion here. And I’m very close to doing this, but today I contacted the MC mechanic who is sending me the 10w-60 oil, and also the other mechanic who sold me the engine.

They both said: “Don’t use a cleaner!”

So I’ll change the oil and filter. If I still have a problem I’ll use a cleaner and change oil and filter once more, and refurbish the starter.

Danish biker wrote: I contacted the MC mechanic who is sending me the 10w-60 oil, and also the other mechanic who sold me the engine.
They both said: “Don’t use a cleaner!”

Did they say that in harmony? Did the mechanic who sold you the engine explain the reason the starter just spins and spins?

Was there a warranty on the engine?

Have you gone to the mechanic who sold you the engine?  He told you it worked properly, he should explain why the sprag doesn't work.

Laitch wrote:Did they say that in harmony? Did the mechanic who sold you the engine explain the reason the starter just spins and spins?

 You haven’t been paying attention  

YES he did. The only thing (except for generator, transmission, wiring, seat etc.), that is the same on both engines, is the starter.

Point-Seven-five wrote:Was there a warranty on the engine?

Have you gone to the mechanic who sold you the engine?  He told you it worked properly, he should explain why the sprag doesn't work.

 He did. My starter is bad. Same starter on my old engine, where the starter problem was way more worse then it is on the “new” engine.

It's years since I read about nano additives, so take this with a grain of salt.

I agree with the mechanic in your first post that you're using the wrong oil (Putoline sport 4R semi synthetic 4-stroke 10w 40) not so much because it's for wet clutch applications, but because of the nano additives (still a guess,  but I'd put my bottom dollar on it)

The hype, or reality, is that it bonds to smooth metal surfaces for many oil changes after it's added. You could contact the oil manufacturer and thank them for their products. Ask if it has nano additives and explain your problem. Tell them it's only been used for 500 km (luckily) since you owned it. Ask for options to remove it if an oil change doesn't fix it.

My last car got over 600,000 km with the original engine using good old Castrol gtx. Typically on fathers day it's $10 for 5lt. In OZ, it's been that price for decades.

I'll bet my bottom dollar (if I've still got it) that BMW wouldn't recommend using nano additives in a brick.

Danish biker wrote: You haven’t been paying attention

You're correct! Once I learned that a miracle was coming, I drifted off. I figured I'd hear the thunder and see the lightning across the computer terminal when it came and I could catch up then.

From your first post:


"On my first ride the starter failed twice. But not as it did on the old engine. Now the bike would actually start if I hit the starter a second time.
 
My conclusion was: “Ok it must be my starter since it was the starter from the old engine”. I got a used starter. Disassembled it and cleaned it and installed it. But I still get starter problems."


Two starters on this engine and you say the sprag still slips.  I respectfully have to say that it doesn't sound like the starter to me.