Occasionally when I start my bike I get a pretty horrible metallic clang/bang as the starter is engaging. Is this what's known as "kick back"? It's a bit alarming! Is my sprag going...? :frown:
Cheers Chris, Fairly regular. Had cold starting probs as well, so invested in a new big ar$e battery! Not sure if the none starting is due to weak batt or non- engaging starter.
Hi Nelson could be the spag on the way out Low battery voltage tends to kill them Have you changed earth lead they will help starting Steve
Hi, Replaced the big cables a while back. Is it just the spring that has to be replaced? Not delved into this part of the bike before.
You can shorten the spring around the bearing to give it a bit more life but might as well replace while in there Use a KTM part same but cheaper google is your friend here procedure is well documented Leave the woodruff key out when re assembling -save ruining the crank when the alternator rotor comes loose Steve
I think Steve meant leaving the woodruff key out. I think nearly all has been covered ^. The difficult bit as you say Nelson is trying to tell if the problem is a lack of transmitting energy due to leads/battery/starter or because the sprag assy is partially binding or jamming because the rollers are worn/scored or the wire 'cage' or circlip is distorted due to repeated slow churning in the past - the symptoms are similar (i.e. engine appears to be reluctant to turn over) but the 'clanging' probably means it's the latter. Early stages of the whole sprag slipping can be saved by retensioning the spring by shortening but not sure it's applicable here. When you get it stripped all will be revealed and you will find it easy to fix the next time As Steve B. has said, KTM is the same but cheaper (around £90?) - I have taken a gamble on secondhand before and got away with it (around £25 - I think there's one on £bay now). See :- http://www.ducati.ms/forums/80-hall-wisdom/66410-repairing-replacing-desmoquattro-sprag-clutch.html
Thanks Chris. very useful write up! I tried the bike this morning when cold (very) and the starter just span and didn't engage, sounds like sprag bol time... There was an awful lot for attempted starting during the bike'a creation, this may explain the issue now.... Fragile little darlings! So; I need to order a clutch holder and case puller. What do you chaps recommend for a case sealer? Have you tried the bearing seal method for the spring replacement? Sorry, what do you mean leave that key out?
Hi Nelson use three bond on the case make your own case puller -three bolts and a strip of steel Clutch holder not needed -borrow a rattle gun /impact socket You will need it to get the alternator nut off -its kinder to the threads than a long bar anyway Just replace the complete sprag with the ktm part Steve
Sorry if this is a stupid question but on the "HowTo" link he says the spring that comes with the SKF seal works fine, does that mean you use that spring instead of the KTM or Ducati spring.?
Thanks Steve, Presumably you'll still need the locking tool to re-torque the nut? Do I remember seeing a post somewhere re a devious method for removing the casing with out the tool? Using the clutch slave or something?
Hi Nelson you can use the slave to help ease off the cover and pull with a bolt in one of the treaded holes IN use the impact gun to put the nut back on no problem Steve
I'm missing something here... How do I stop the clutch plate moving out so the pressure pulls the cover off? Thanks again
yes it is the whole assy - the spring from the seal is a method to save your existing one if only the spring has stretched. Re: undoing/doing up, I cannot recommend more highly :- Clarke CEW1000 1/2" Drive Electric Impact Wrench. I was sceptical about the ability of 13 amp to kick a big enough punch to undo very tight large nuts but boy was I wrong and using above at what I think is a total bargain price of around £50 is a total luxury for me. Makes replacing a 748/9 etc rear wheel a 'doddle'. Only thing lacking is not knowing what torque you have retightened to but you could check if necessary with a wrench. I shortened my existing spring the first time Nelson but would be happy to use a seal spring as mentioned if it sat happily in the sprag groove.
never tried it myself - I guess it's 'trying' to part all the time you have clutch pulled in but the springs compressing are the weaker of the opposing forces. You could replace 2 or 3 springs with solid bushes but i wouldn't risk it myself as asking for trouble and could damage slave seal etc.
You don't have to do anything to clutch Equal and oposite reactions was it newton? Having done this several times now would not mess about with the spring unless you have caught it very early Leave woodruff key out of the alternator rotor it only destroys crank when the nut comes loose Steve
