A problem with start freewheel

Hi Neil,

Thanks for that - I am starting to get a better understanding of how this odd little part works and how it might be affected by stiff oil.

Cheers

Mark

er please!

this is a family site and we don't need to know about your medical problems!

regards

Taffy

Ok Taffy

I walked into that one...

Mark

What do you all reckon to this, when I got the new limiter from Dan it worked perfect and did so for about four hundred miles, then I changed the oil, before changing it the level ran at the bottom of the glass, when I refilled it I took it to about 2/3 up the sight glass (yes I know what the manual states)and guess what I had starter slip from cold but 100% good when hot, I reverted not to use the starter from cold only on hot restart.
I've covered about 500 miles from the last change and the level is now about a third up the glass, and now there is no slip from cold.
So we could have a two fundamentals here quantity, temp. seems to have a bearing on how well the the starter set up functions. There could be to much oil drag when cold, I say cold it's about 15c here in the morning but a dam sight colder in other parts of the world.
The slip by the way is from the sprague totally different noise from the limiter as I stated before.
So lads if you have this cold slip condition drop the oil level and see if it makes a difference.
It was just a coincidence to how I found out what was happening.
Just a thought.

Regards

Sparks.

I can't see how oil level would have any effect on sprag operation. It is way above the oil level and would do it's job before any extra oil was flung up there. Temperature vs oil viscosity would be the biggest factor in my opinion.

If the sprag elements are worn, they would have trouble "hooking up". This is where extra spring tension would be needed. As the sprags wear they develop a tiny flat spot. This can be on the ID surface or the OD surface. They are pretty much done once they wear that far.

Neil_E. said:

I can't see how oil level would have any effect on sprag operation. It is way above the oil level and would do it's job before any extra oil was flung up there. Temperature vs oil viscosity would be the biggest factor in my opinion.

If the sprag elements are worn, they would have trouble "hooking up". This is where extra spring tension would be needed. As the sprags wear they develop a tiny flat spot. This can be on the ID surface or the OD surface. They are pretty much done once they wear that far.

Click to expand...

Neil, I am not talking about the oil effecting the sprague directly but extra drag on the other engine internals.
I do know the full workings of the clutch, the one I took out did have small flats on the rollers but it has been replaced with a new one.
So Neil now can you explain when I didn't initially have the slip then I did now I don't.

Regards

Sparks.

In regards to oil quality, I had one Aussie dealer say to me they had seen sprag/limiter related issues go away with a change from full synth back to a part synth blend......

I think the significant factor is the oil being used. Since the sprag needs friction to work, but must also be lubricated so it can slide without excessive wear, it's a bit of a balancing act. This would be the same as how clutch noise changes with the type of oil used. Some oils will have the clutch squawking more on engagement. Kind of like the Motul vs Motorex or Rotella vs Delo thing.

The oil type (and weight) will effect the friction point of the sprags. Increased spring pressure will help them grab, but will also increase the wear rate. When the engine is stopped, the spring pushes them to make contact. When the engine is running, rotation pushes them to run free. Even when the sprags rock slightly to be free, the spring pressure keeps them rubbing all the time.

Try different brands of oil to see what works best. Even clean vs dirty oil could have some effect.

Hannu said:

I checked the almighty Google and found an interesting way to repair the sprague by shortening the spring. Very simple and it works(tried the shortening).. http://www.mad-ducati.com/Technical/Sta ... lutch.html
Has anyone tried it in practise?

- Hannu

Click to expand...

OK
i shortened a spring today and it was a nightmare to do!

i ended up snipping the spring in half and then had to cut equal amounts off either end. then the REAL problem! i couldn't find a satisfactory way for the two to intertwine and stay locked. i need a small flexible barb that will go inside the spring. flexible because the spring must always be in a "natural" cirular shape!

this barb should gaurantee that the spring will never come undone....
i estimate the barb should face out in each direction and be only 1mm in diameter. very small!

so come on you lot - start thinking!

regards

Taffy

Taffy said:

so come on you lot - start thinking!

regards

Taffy

Click to expand...

Taffy,
Why weren't you able to unscrew the spring in the opposite direction it was assembled? It should have been somewhat straight forward like the picture in this link. There is a definite joint where the spring is screwed into itself.http://www.mad-ducati.com/Technical/StarterSpragClutch/SpragSpring2.jpg

I know it's a long shot but do you have any old fork seals laying around? Pull out the spring and see how it compares in size.

log

logjump said:

Taffy said:

so come on you lot - start thinking!

regards

Taffy

Click to expand...

Taffy,
Why weren't you able to unscrew the spring in the opposite direction it was assembled? It should have been somewhat straight forward like the picture in this link. There is a definite joint where the spring is screwed into itself.http://www.mad-ducati.com/Technical/StarterSpragClutch/SpragSpring2.jpg

I know it's a long shot but do you have any old fork seals laying around? Pull out the spring and see how it compares in size.

log

Click to expand...

The spring and the joint are small and hard to see. Magnifying glass helps a bit. Cut the spring to desired length before unwinding it (make sure you cut the right=outer side of the joint). It's a lot easier that way.

-Hannu

Hannu said:

The spring and the joint are small and hard to see. Magnifying glass helps a bit. Cut the spring to desired length before unwinding it (make sure you cut the right=outer side of the joint). It's a lot easier that way.
-Hannu

Click to expand...

and i guess that's what i did wrong!

i snipped a bit off both ends. i was in the garage and thought i'd have a go. never saw your photo.

i'll have a look for another spring but at least for the rest of you yo now have a lead into getting it right.

regards

Taffy

"Remove the outer gear for nowso that you have just the splined shaft complete with 'keyhole' ratchet and tiny spring fitted. The diagram in the parts manual shows the spring the wrong way around, you need the straight pointed end to face away from the bike at you and the hooked end goes into the recess in the cases and fits over a long sharp ledge.

Firstly though, fit the straight part of the spring into the centre of the kickstart mechanism and then fit the hooked end into the engine case feeding it all in as one. Leave the body of the kickstart outside the crescent and fit the kickstart arm and wind the unit 180 degrees clockwise until the 'keyhole' shaped ratchet piece goes past the high point of the crescent plate. Now, holding the keyhole 'closed', press the unit down into the case and release. The unit will turn counter-clockwise and rest against the shoulder of the crescent. Now remove the kickstart and you're ready to fit the gear. Because the keyhole is 'in', the gear will drop on!"

regards

Taffy

I have tryed all

I have try all the tricks i read about here and not one of them works i put a 0.4 mm shim in the torque limiter and i have put much smaller spring around the Sprague clutch lager.

But nothing works so i took the spark plug out and try to start without it and that do not work either so i just talk with the dealer here and he told me he will order new Spraque clutch for me from newer version of bike and he also told me that will last longer because the material is better now-days then before.

Do any of you know if that is truth or is it just a sales trick because the prise is a litle bit higher on those younger model parts then the old ones

Cheers and have a nice weekend :twisted:

RE: I have tryed all

to repeat, as said, the earlier ones had no clutch but were solid. now fitting one of those would really narrow the problem down donchya think?

regards

Taffy

Update on my low 06 FS605e with a slipping starter (presumably the sprague)

Well spring finally arrived. To recap:

-the bike has 1,100 km and 30hrs on it, all easy street riding
-I ended up running a 20W-50 as it was the only quality oil avaiable at the time
-below 15degC last year the starter started to slip and got steadily worse as the temps continued to fall
-At the end the bike would not start on the button at 18degC in my house
-After some research and some good threads on UHE I settled on the heavy 20W being a significant factor
-I waited for spring to test my theory...
Well today I dropped the 20W-50 and put in 0W-40 Rotella to see if the lighter oil would improve e-starting, though I suspected my sprague had already seen too much slipping and was finished. I fully intended to have it slip again and force me to tear it down to install a new sprague

Will wonders never cease - at 10degC the happy button worked just fine with the 0w-40 and the beast lit right up.

All of this is to say, if you find your sprague is slipping at cooler temps, try a lighter oil, it brought back my e-starter.

I will try 5W-** next and if it works well at my cooler temps I will probably stay with that for the long haul.

Thanks to all for their input over the winter.

Cheers

Mark

I still do know for certain if it was a sprague or a freewheel issue, but based on Sparks description that the freewheel produces a squeeling noise - my issue was the sprague. I have a new one, just in case this all goes sideways again.