My 1985 K100RT would intermittently just spin when I hit the start button. After a few tries, it would engage. I was blaming the cold winter temps. Tonight , it will not engage. Any suggestions?

Common problem my friend. Search sprag clutch and you will find quite a bit on it.

If you can still get it to catch most times, change your oil and use a high detergent diesel oil and it should clean the nasty sticking bits as you ride.

+1 on that and it wont take very long to get it working again. 3 or 4 50 mile rides will do the trick.

I had a problem with sprag clutch after install a battery with non adequate crank power (180 instead 300 plus). My advice check the battery first, K starter needs strong, fast kick to engage sprag clutch properly.

Regards

A quick temporary fix in order to start the bike:
On my K75, once in a while, the sprag clutch wouldn't catch. I just had to put the bike in 3rd gear and rock the bike back and forth (only a couple of inches).
The sprag clutch would then engage and work again for a week or two.

On other forums, I have read about people removing the oil from the engine, filling up with diesel fuel and running the engine for 5 minutes. It works and Apparently the engine doesn't suffer. The only problem is that you have to change oil and filter at least twice after this treatment.
Last year, my brother used this method to clean the gunk in his engine.

I personally would not try it on my bike.

CF

Crazy Frog wrote:


I personally would not try it on my bike.

CF

I'm with you on that one

But I would go along with using a high detergent content diesel engine oil every now and then.

Then drain and change oil and filter.

Crazy Frog wrote:A quick temporary fix in order to start the bike:
On my K75, once in a while, the sprag clutch wouldn't catch. I just had to put the bike in 3rd gear and rock the bike back and forth (only a couple of inches).
The sprag clutch would then engage and work again for a week or two.

On other forums, I have read about people removing the oil from the engine, filling up with diesel fuel and running the engine for 5 minutes. It works and Apparently the engine doesn't suffer. The only problem is that you have to change oil and filter at least twice after this treatment.
Last year, my brother used this method to clean the gunk in his engine.

I personally would not try it on my bike.

CF

By rocking it you dislodge some of the gunk and it works for a while. Running it with diesel fuel wont actually do any harm so long as it is cold when you do it and dont get it to operating temp that way the fuel which is a low viscosity oil doesn't get a chance to thin out. It isn't a very successful way to clean out the deposits as most of the deposits are not soluable in oil or they would come out with the old oil. The diesel oil with high detergent is ok to use but don't go using it on an engine that hasn't got a lot of life left, it will with prolonged use get rid of the carbon deposit behind the rings and they lose their tension which was only there because of the deposits and you get a very rapid failure of the rings. The pistons are liable to fail as well when the ring glands open up and break away the lands and even bigger failure. They dont usually go boom but more like a fizzle and with a brick those failures will damage the nicasil bores.

Art, I see turbo on your bike. Tell us some about experince with turbo on K bike, temp, power, driving, maintenance. What is mileage with turbo?

Thanks for the advice all. I will re-address the issue later today.
As for the turbo, I have had the bike for 2 mo. and only just taken it out last week to ensure the turbo does in fact produce boost. It did (5psi?) but it is most enjoyable. After I get some miles I will report

Diesel fuel ? or diesel engine oil? Running with diesel fuel as engine oil is an old old bad bad way to clean anything out. If you have to do it let it there for only a short time or bearing wear will be serious.
Engine oil for a diesel is a good way to clean out the sprag clutch, mine would not work at all after salt water immersion, running it on good quality diesel engine oil was a success. Almost three years on and its still perfect.
Alternatively a good tap with a blunt instrument just in front of the alternator will always engage the clutch. I dont know how easy it is to this on the bikes.

A fair few of the gents here on this forum use diesel oil regularly. Its cleaning properties and turbo rating make it an ideal regular-use oil for the Mighty K. The added benefit of keeping the sprag clutch clean and sticking-free is a bonus. I use it about every third or fourth oil and filter change for that reason.

BTW, so you're in Westford, Mass. I have a younger brother who finds himself living in Pepperell (with an Airhead RS in his garage), not very far away from where you are. I once worked at Murray Printing in Forge Village, near the lake, back in the late '70s when I was a lad earning my journeyman's card. I rode through there on my RT several months ago on my Ride Right Round, and waited out Hurricane Sandy in the western part of the Commonwealth of Massachusetts. After arriving from Australia the first time I did my last two years of high school in Townsend. All of my formative road riding years were done right in your riding neighbourhood. Some very good memories. Cheers.

Small world! I dream of seeing Australia some day. Its nice to hear of your time in the area. I am on the border of Forge Village and Graniteville. Looks like the printing buildings are going Condo/ Office space, right down by the Cold Spring dam! Nice to here from you.Did you ever get to the Stone Arch Bridge in the Russell bird sanctuary? It is about 100 yards from my house.
Art

I don't recall the bird sanctuary, but there was a local restaurant we'd take our break in across the dam. The brown brick printing buildings were at one time the third largest book-printing/binding facilities in the world. This was 1979. I was a year out of American high school. I do recall a certain young lady whose parents owned a Summer home/log cabin in the pine trees across the other side of the 'pond', as it was known, from the printing shop. She had her charms and I would eagerly ride my R75/7 round to meet her on hot days for a swim and a pash whilst her parents were at work. I wouldn't have a clue where she is today, but she sure had my attention in the dog days of Summer back then.

...about that starter not engaging... lol

Believe it or not early Goldwings suffer from the same problem with the starter clutch. I know because I had to deal with it a few weeks ago.

Solution was to inject good oil into the clutch assembly after drilling a hole in the side of the engine housing and then fill the sump with diesel oil, in this case semisynthetic 5w-40 made by Penrite ( http://www.penriteoil.com.au/products.php?id_categ=1&id_fuel_type=3&id_products=7 ). I like them as they publish all the relevant data for all the oils and they are conscious of motorcycle requirements (JASO MA standard)

After a few starts and short runs, all is OK

Side benefit is that now I can see through the site glass to check my oil levels without torches and mirrors ... the internals got so scrubbed clean that the window is now clean and the back mirror sparkles.

I think that I will keep using this oil as it passes JASO MA standard (wet clutch thing) and has full Zn levels.

I had this problem for some time and finally bit the bullet and did THIS

Albyalbatross1 wrote:I had this problem for some time and finally bit the bullet and did THIS

see your image :



On my GW I've drilled a 8mm hole in the motor case so that I can inject oil or cleaning fluid into the clutch assembly hole (that hole) and loosen up the clutch components.





By tapping an NPT or BSP thread I've put in a plug in the case so that I can get access to the clutch whenever I need to.

As GW has a kick start mechanism I can use that to rotate the engine slowly to line up the holes... I guess one can use the rear wheel to do the same.

I don't know if that is possible on the K100, but if it works it may save you removing the engine to fix the problem. ...Just a thought.

Ned- That is the best graphic on your helmet!
Alby- I didn't think it would be easy. You proved it!
I will try high detergent diesel as soon as the temp. gets above freezing
Art

ARTCOLLINSJR wrote:Ned- That is the best graphic on your helmet!
...

Thanks, as i work for the Australian nuc people, it is appropriate

ARTCOLLINSJR wrote:Ned- That is the best graphic on your helmet!
Alby- I didn't think it would be easy. You proved it!
I will try high detergent diesel as soon as the temp. gets above freezing
Art

Be brave it is not that hard..you ust have to lay everything out. You do not have to change all the bearings..I only did because it was what I wanted to do. If you just clean the sprag..Too easy.

I'm due for an oil change and I'm thinking I will try Ned's suggested Penrite.......
My question is, Is it ok to use for my entire 5000km service interval or do I just run it for a short time?

AFAIK most of the guys run it all the time, I know TWB does and that lil red rocket still goes well.

When you're at your sprag clutch you might want to modify it as BMW did with later models and as indicated above (for a different reason though :-)). The crud stayed in the clutch area and fouled it, making the little prongs sticky and not fully engaging due to limited flow through the clutch. Drilling a few holes in the circumference would allow for a better flow and therefore less build-up inside the part. As always YMMV.

73MOH wrote:I'm due for an oil change and I'm thinking I will try Ned's suggested Penrite.......
My question is, Is it ok to use for my entire 5000km service interval or do I just run it for a short time?

Hi Paul have been running Penrite environmental diesel oil for months and it is fine....10W40 which is what I use in my Hyundai Santa fe....all good so far and sounds /performance is fine.

73MOH wrote:I'm due for an oil change and I'm thinking I will try Ned's suggested Penrite.......
My question is, Is it ok to use for my entire 5000km service interval or do I just run it for a short time?

I use penrite for two reasons:
a. it is a local company and
b. they publish data and cater for bike use.

If u have spragg clutch problems then synthetics or diesel semi-synth is accepted to be the cure for this. I think that many people have documented the fact that synthtics are a good engine flush.

I see no reason why u couldn't use your full 5000km service interval. I tend to use fully synthetic 15w-50 in both K100 and K1200 and change every 6-7 months.

I couldn't wait for the weather. Its just getting colder. I got a gallon of diesel detergent oil, drained the crankcase, filled it with the diesel. Mind you, it is 18 deg f (-8c). I rocked the bike in 3rd, but the starter was unwilling to engage. So, I bump started it, and rode for 2 miles or so. Rolling, I hit neutral, shut the engine off, key on, and OH YEAH!! we has a functional starter. Thanks all.
I cant post pix, or I would post the pic of my front tire with snow on it. But, another puzzle. Under the battery are 2 hoses which look like they go thru the casting. The one on the left side is about 12" long and ends in an plastic elbow. It is not attached to anything. It is maybe 1/8" OD hose (4mm?) and black. Where should it be going?
I'll post pics when I am authorized to find out how!

The one with the elbow is battery breather.

Thanks. I have a maintenance free batt. so all is well

ARTCOLLINSJR wrote: I'll post pics when I am authorized to find out how!

https://www.k100-forum.com/t998-posting-pictures-and-movies


It isn't any other hoses that goes through the gearbox casting....as far I remember.
Only the wires to the GPI switch.

I didnt look to closely at the other item

I think someone mentioned diesel engine oil earlier in this thread

Though you have some joy now, keep running that oil in the crankcase until the next scheduled oil change. That will ensure you have a clean engine on the inside...

+1 on the battery breather hose, though I feel a bit foolish +1'ing anything Inge says. Of course he's right...

ARTCOLLINSJR wrote:I couldn't wait for the weather. Its just getting colder. I got a gallon of diesel detergent oil, ....

Do you mean diesel crankcase oil or diesel fuel oil?.. I hate to see u ride any distance with the fuel in the crankcase.

As diesel oils are usually 5w40 or 10w40, u should have no problems using it for the duration of the service period, especially in the cold weather of the northern hemisphere.

The other Hose is quite likely the lead to the Gear position indicator switch which is behind the swing arm and well hidden. It should go to a 4 pin plug behind the right side cover.

I am running diesel grade motor oil

Been off line for a few weeks. Jan 22 at 16 deg F. I bumpstarted the K. Pushing it up the driveway, I felt a burning in my esophagus and small headache in temples. Just out of shape. This had been happening for a couple of weeks off and on. Wife says "go to Dr." So I made appt. Went to primary care, EKG iffy. Sent to cardiologist. Ultrasound (heart). Didnt like what he saw. Sent to Hospital. Admitted to have heart catheterization, with dye to look at coronary arteries. Came out with news that "stent" was not possible. I needed "CABG 3x" (Coronary Artery Bypass Graft, triple"
So, on presidents day they laid me open, stopped my heart, and performed the repairs. I was very close to the other alternative, as my arteries were 95% , 80% and 80% blocked. 3/25 I will have been off the table 5 weeks, and other than going back in to remove 1200cc of fluid from my chest cavity, I am getting back to a semblance of my old self. Will see surgeon next week for a green light to start P.T., and the ok to drive again.
Apparently I had "silent " heart attacks prior to the hospital visit. My advise to all..have your yearly checkups, watch the "bad" fats, and ride those K bikes. Winter here will not let go, probably so I am not tempted to ride before I get the OK.

Just sent a PM but adding here to... Good to hear that your on the mend.

Twincarb

crikey art !....get well soon ...hope your riding days are with you again soon ...

Here's to a full recovery and health to enjoy.

FWIW, a mate of mine had similar surgery fifteen years ago and he's more active now than he'd been for years.

If you just add a cup or 2 of Dexron ATF to the motor oil & drive 500 miles. You'll be all good.

Good to hear you're on the mend at least Art. I've reached the age where seems like everyone I know is having ticker trouble, must have been the childhood diet.(never the beer or lobster in butter mmmmm lobster).
RT

Well bad news and then good news Art. Glad you are still with us so who can say now that Ks are bad for your health it may have saved you.
All the best

Art

Good to see you back. Happened to a work colleague a few years back, he went for the check up and was told to 'call your wife and have her bring your things'. No tea, nothing, straight to surgery and the works.

Two months later, he looked 5 years older, a year later he looked five years younger........back doing everything and more.

All because of a lucky call.

Take care of the body!!!

Being old enough to become a full member of Ulysses seems to have more drawbacks than advantages.
All the best mate. Take care. Stay off the cheese. That is not a euphemism. That stuff will kill you faster than milking a bull.

Thx all. Now...back to bikes!

A little OT but some hospitals are now able to do coronary bypas surgeries orthoscopically. No big seam down your chest, fast recovery.

Back on topic. A sprague clutch is a one way clutch. All you are doing by rolling the bike backwards in gear is forcing the engagement of the spragues mechanically. Lack of drain holes in the original design of the starter sprague (sourced from a jet engine starter!) combined with infrequent and/or short trip use is the usual cause of the starter spragues hanging up. Oil does not drain properly and congeals. Really, all you need to do to remedy this is a good hard run where whatever oil you are running in the bike is fully warmed. Run the stink out of it, get it hot enough to engage the fan. That will usually clean out the sprague clutch and restore stater function. The replacement design has more holes drilled in the housing.

I found that putting it in gear and rocking it makes the sprag grab so it can be started but isn't by any means a fixit. Using the high detergent oil works well but I have reservations on using it because it also can clean the carbon build up from behind the rings and absolutely kill an old and marginal engine and leave you stranded.
BTW has anybody noticed if the K75 is less prone to the problem. I ask this because when you stop many of the K75s the engine will rock backwards off a compression stroke and force an engagement of the sprag which may stop the build up occuring. Just something interesting.

Rick G wrote:... Using the high detergent oil works well but I have reservations on using it because it also can clean the carbon build up from behind the rings and absolutely kill an old and marginal engine and leave you stranded....

Did just that with my Goldwing GL1000, 1976)... it scrubbed the engine clean, spotless in fact The thing loosened up to the point that it is a different bike now. It solved my spragg clutch problem, I can now see the oil level in (now) a clean window and it solved my neutral switch problem (that is another story).

For those who are interested I used 5w-40 Penrite (HPR Diesel 5) semi-synthetic. This oil is JASO MA rated so it is compatible with the wet clutch set-up. This is of no consequence to Ks, of course.