Had the bike finally stop working this morning the starter motor does engage so I know it's not that; definetly the sprag clutch. So I've managed to bump it pushing it up a big hill to get momentum; not sure I can do this again which means I'm doing a strip.

Point of this thread is to ask if there is anything I need to buy or worth replacing on my k10084rs whilst doing the strip. Like seals, crush washers, rubbers.

I was going to replace the sprag clutch with new but no one that I can find has a new one in.

There are a few options without doing a strip down, starting with an oil change using a flushing oil and a few frequent oil change [ I would g this road first unless its been a very frequent issue]. Up to and including drilling into the housing to get a cleaner into the sprag clutch- 88 on the forum here has done this successfully.

But if you have other reasons to go in then maybe consider doing everything else in there.

I had mine apart in February due to failed rear main seal and gearbox leaking oil all over the place.

So I did the lot, as in rear main seal, flywheel seal, gearbox seals, clutch plate and bolts, gear position indicator switch and gasket, release bearing, clutch pushrod boot clip etc. alternator monkey nuts [didn't replace, done 2 years ago and still good], possibly new clutch cable if old one is dodgy [do it anyway and keep old one as a spare], clutch pivot bearings and circlips, driveshaft boot and new clip, exhaust gaskets studs and nuts. Just been in and done all mine and got best price from Motobins. Because I was faced with postage costs I went and ordered the lot in one order and everything was here when doing the job. I did a few other jobs too- brake switches and fitted hazard warning switch, Motobins is a simple plug in and go.

If you do go in to the sprag clutch you would probably be mad not to do the lot or at least do the rear main seal as it will go and when it does clutch plate goes with it. I had 78,000 miles on and the clutch [original] had at most 5,000 miles left in it.

Over a few weeks I dosed everything and I mean everything in WD40, not one nut or bolt troubled when taking it apart. The bike lives outdoors under cover.

For now its oil tight. I have also done final drive bearing and brakes since too.

@92KK 84WW Olaf wrote:There are a few options without doing a strip down........

Up to and including drilling into the housing to get a cleaner into the sprag clutch- 88 on the forum here has done this successfully.

Oops Olaf. There is NO need to drill. The oilway hole is already there.
Read this document

Excellent article CF.

My friend has just bought an RS Style and it has this problem, unfortunately he is not online so he will get a copy of this document.

@92KK 84WW Olaf wrote:There are a few options without doing a strip down, starting with an oil change using a flushing oil and a few frequent oil change [ I would g this road first unless its been a very frequent issue]. Up to and including drilling into the housing to get a cleaner into the sprag clutch- 88 on the forum here has done this successfully.

But if you have other reasons to go in then maybe consider doing everything else in there.

I had mine apart in February due to failed rear main seal and gearbox leaking oil all over the place.

So I did the lot, as in rear main seal, flywheel seal, gearbox seals, clutch plate and bolts, gear position indicator switch and gasket, release bearing, clutch pushrod boot clip etc. alternator monkey nuts [didn't replace, done 2 years ago and still good], possibly new clutch cable if old one is dodgy [do it anyway and keep old one as a spare], clutch pivot bearings and circlips, driveshaft boot and new clip, exhaust gaskets studs and nuts. Just been in and done all mine and got best price from Motobins. Because I was faced with postage costs I went and ordered the lot in one order and everything was here when doing the job. I did a few other jobs too- brake switches and fitted hazard warning switch, Motobins is a simple plug in and go.

If you do go in to the sprag clutch you would probably be mad not to do the lot or at least do the rear main seal as it will go and when it does clutch plate goes with it. I had 78,000 miles on and the clutch [original] had at most 5,000 miles left in it.

Over a few weeks I dosed everything and I mean everything in WD40, not one nut or bolt troubled when taking it apart. The bike lives outdoors under cover.

For now its oil tight. I have also done final drive bearing and brakes since too.

Cheers for the reply, I replaced my clutch on the bike about 14k miles ago at about 50k before the bike got stolen and would like to get in there to check everything is still ok. It did have a hard ride being shipped to america and ridden to canada to be starred in the 1986 expo (has a plaque to prove it). Then it was taken to Ireland, Isle Of Man, France, Spain, Germany, Holland, Sweden, Poland and Italy. Don't fancy drilling into the engine casing not that confident so that one is off. I've also tried bump starting it today had to do it down a hill because the bike wouldn't bump by pushing or by rocking back and forth in gear. Not sure I could bump it again if it happened to stall or I needed to stop whilst out trying to clear it.

I'm interesting how you got the best price from motobins and how much it all came to I know I won't need the clutch disk hopefully. But I plan on getting mine done by the 27th at latest.

@TheJoker wrote:
Don't fancy drilling into the engine casing not that confident so that one is off.

There is no need to drill. you just have to remove the crankcase cover to access the oilway hole. Read the article that I posted.

99% of the time, there is nothing wrong with the sprag clutch other than dirt (or sludge from the oil). If you remove it, you are better to clean it and re-install it. This will save you $$$$. If you buy a used one, you will have to clean it anyways.

If the sprag clutch is not driving the crankshaft, in stead of pushing the bike, get it in 3rd gear and try to rock the back wheel back and forth a couple of times. Most of the time the starter will work after that.

@Crazy Frog wrote:

@TheJoker wrote:
Don't fancy drilling into the engine casing not that confident so that one is off.

There is no need to drill. you just have to remove the crankcase cover to access the oilway hole. Read the article that I posted.

99% of the time, there is nothing wrong with the sprag clutch other than dirt (or sludge from the oil). If you remove it, you are better to clean it and re-install it. This will save you $$$$. If you buy a used one, you will have to clean it anyways.

If the sprag clutch is not driving the crankshaft, in stead of pushing the bike, get it in 3rd gear and try to rock the back wheel back and forth a couple of times. Most of the time the starter will work after that.

I did read this but didn't fancy doing a double post just for the sake of it. I've tried rocking the bike in each gear to start it but none of that has worked. Could try the oilway hole but a long trip would be risky work encase the bike stalls or I have to stop. Although I do have two bolts leaking from the crank case already.

With my recovering left hand I'd be screwed. So I think I'm best off just pulling it and giving it a clean; I was thinking new as then I know it's not going to play up but can't find it anywhere anyway. Hence why working out if there is anything else worth replacing whilst I've got the back end apart.

If you remove the back end the following things should be checked:
- The transmission Gear indicator should be cleaned and generously coated with silicone(or similar product). Overtime, the plastic become brittle and they are not waterproof any more.
Just check for the TGIP chapter on This page
- The shaft for the clutch actuator should be removed and cleaned (Careful not to break the boot when you remove the actuator) Just read on This page .
- Swing arm bearings have to be checked.
- output engine seal should be replaced. This is quite cheap and will avoid a later removal of the gear box and clutch to fix the problem.
- As usual, greasing the output shaft with the same grease as the driveshaft.

"Had the bike finally stop working this morning the starter motor does engage so I know it's not that;..."

I don't know if I should be replying to the statement above, but here goes: The same thing happened to my bike. I hit the starter button, the starter would click as if trying to start the bike, but it won't turn over.

Now from previous experience I know that it's the sprag playing up from the bike sitting unused (shock, horror!). So I started "tapping" the starter button, hoping the on/off engagement of the starter may free the sprag (brand new fully charged battery). The tapping consisted of me pressing the starter button down for a full second then releasing it.

After about 10 or so "taps" it did free up and the bike started. Has been running fine ever since.

I do not recommend this procedure to anyone; I'm simply stating that it worked for me.

My friend locally who is ex BMW also only recommended cleaning the sprag clutch, nothing about replacing it.

I have had to do Blakey's trick too....it works well. Short stabs.....

Condensation inside the engine during cold weather certainly doesn't help it, so some extra oil changes in winter are a help. I wonder could we look at the problem and see does it affect all Ks or just those in some climates?

Lack of use?
Lack of maintenance (overdue oil changes)?

Problem with sprag clutch occured after I mistakenly instaled battery with only 180 cca cranking power, instead od 250 - 300 needed for K 100. My advice is to check battery punch first. Old sprag needs fast spining to engage.

Blakey is on the money there.

My K does not suffer lack of use, but I have noticed that over 4,000 miles on an oil change is when it has acted up and always in the colder weather. Now doing oil changes around 2k miles and don't expect to see any problem.

I don't know the history of my K prior to my getting it other than it came with 36,000 miles in 29 years......lack of use back then I think. But its now about to turn 80,000 miles after less than 4 years,

Bert's post is excellent and exactly why I love this forum. I think 88 discovered that after doing the hole drilling route.

In my experience lack of regular use, which may also contribute to lower performance from the battery, is a significant cause of the sprag clutch issue. I have had it a few times over the 20 years that I have owned my K1100 and been lucky enough to get it going with the rocking back and forth in 3rd of 4th gear method. As you all know, down here in Oz we don't suffer from the long periods of cold damp weather that some of our friends in the northern hemisphere experience.
Over the last couple of years I have taken to using an engine flush product at every second oil change (I change oil & filter every 5,000km). The product I use is added to the oil and then given a hard run for 15 minutes or so immediately prior to dropping the old oil. So as I approach an oil change I let the oil level get down towards the lower edge of the sight glass and add the flush product when I'm ready to do the change.

Maybe I've been lucky but no starter issues since I've been doing this.

Cheers

Well I know its not down to lack of regular use or the battery. For one I've been using it constantly since it got motd last month. Plus the new battery is lithium with enough cranking power. It was sat from June 2016 till last month though whilst I was sorting something else; this was outside under a cover with the oil in.

My experience would suggest that sitting June 2016 to last month in our climate is highly likely to induce the problem. Condensation within the engine gets into the oil and the heat drives it out of the oil where it will condense again on the inside of the engine casings

A few oil changes should solve it, if it was mine and has never been an issue I wouldn't go opening it up just yet.

Dont have much choice olaf it won't start at the moment. So I've already started the strip down few hours and the gearbox is out already.

Its not the end of the world if its diy especially if the clutch was out not too long ago.

Not sure its necessary to replace it, cleaning is always what seems to be recommended. Even my ex BMW guru goes for the cleaning option.

Well I've got to the stage of getting the sprag clutch out however my housemate has had his bearing puller stolen. Anyone know the correct size puller needed?

I had problems with sprag clutch after winter. Sometimes didn't start and had to make a downhill start. I put ATF transmission oil and Delvac 50/50 in and let the engine warm up about 15min. RPM was like 3500-4000. I did many starts after that with pulling the bike back/forward gear in. Then new Delvac diesel oil 15W40 + filter.
After that prosedure no problems with a sprag clutch.

I will put a bottle of Rislone later. Just in case!