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Starter (sprag) clutch replacing

Posted: Mon Apr 13, 2015 2:03 pm
by Kioors
Oooh boy, I'm not celebrating italian engineering these last days!

I bought my last 907 now about a month ago. I started by giving it a good proper maintenance, and then rolled it out for a first ride.

After approximately 35km's It started to leak oil badly. Now I can't blame italians for that one, as I didn't thighten the oil filter enough. (Hand tight, yeah right!)
Next up, after another 15km's the regulator went.
Having replaced it this weekend I pushed the bike out for a ride, tried to start it, but nothing... Switched it back off and on, tried again: "whiiiiiiiiiiiimmm". Now the starter just goes 'round without engaging.

That was the end of my sprag-clutch I presume...



Anybody any tips for replacing it?
I've seen mentioned you can buy a KTM-one that's cheaper and will fit? Is that right? anybody has any experience with this?

It seems you have to take off the alternator and the water pump in order to replace the clutch. Do both come off by simple unscrewing, or does one need special tools, pullers, heat and a hammer? I presume you need a tool to stop the crank from turning round while unscrewing the alternater rotor...



All tips are appreciated!
Matthias

Re: Starter (sprag) clutch replacing

Posted: Mon Apr 13, 2015 9:31 pm
by englishstiv
Hi and Welcome

Just to let you know by way of a reminder that we have a wealth of information in our historical threads just put in the details example : "starter sprag" and you will be amazed what can pop up for example

http://forums.ducatipaso.org/viewtopic. ... rter+sprag



This is about the parts you inquired

http://forums.ducatipaso.org/viewtopic.php?f=3&t=6327


It's often easily forgotten and can often be a lot quicker than waiting for a reply especially as most folk will be getting out on the road again.

Good luck on your purchase I am sure it will be a summer spent more riding than tinkering. :thumbup:

Re: Starter (sprag) clutch replacing

Posted: Mon Apr 13, 2015 11:13 pm
by higgy
not that hard to get to, tools you can make yourself Most likely all you need is the spring for the sprag bearing
do a little searchin and let me know if you can't find what you need.............

http://www.ebay.com/itm/SPRING-FOR-DUCA ... 1542779314 Thanks G

http://www.mad-ducati.com/ShowPage2.php ... 1Tn96l2m45

Re: Starter (sprag) clutch replacing

Posted: Tue Apr 14, 2015 7:36 am
by paso750
The first link doesn`t work higgy.
If the starter sprag clutch is ok and only the spring is gone you can find one here:
http://www.ebay.com/itm/SPRING-FOR-DUCA ... 1542779314

Re: Starter (sprag) clutch replacing

Posted: Wed Apr 15, 2015 3:19 am
by 900streetfighter
I changed a sprag on a 907 many years ago. Did it in my hall. I laid the bike on its side and didn't have to drain the oil.

Re: Starter (sprag) clutch replacing... Or not.

Posted: Thu Jul 02, 2015 12:28 pm
by Kioors
Ok,

I finally got round to repairing the black menace, and after a good night of wrenching, I am happy to say there was nothing wrong with the sprag clutch..

Unfortunately I am not so happy to announce the real problem: a sheared off crankshaft... :cry:
2015-07-01 23.08.27b.jpg
2015-07-01 23.08.27b.jpg (104.96 KiB) Viewed 8360 times
The reason the starter freewheeled was that the flywheel broke loose from the crank. That, too, explained why it wasn't charging anymore of late. The rectifier was proably ok, but the alternator rotor was lying around disconnected in the stator.

so... Anyone in W-europe who has a spare crank lying about? Spare engineblock maybe?

But on to the more important question: does anyone know what other Ducati models use the same crankshaft? ST2 possibly? maybe 900SS of even 4v 916-996-998 models?

Re: Starter (sprag) clutch replacing

Posted: Thu Jul 02, 2015 1:12 pm
by paso750

Re: Starter (sprag) clutch replacing

Posted: Fri Jul 03, 2015 3:15 pm
by Kioors
That looks like a good deal indeed.

Now for the next problem: when opening the sump, the shafts, and especially the new crank, have to be shimmed up right. That'll be a first time for me too. So: anybody a how-to, or some tips & tricks?

Thanks a lot guys!

Re: Starter (sprag) clutch replacing

Posted: Fri Jul 03, 2015 4:12 pm
by paso750
if you want to do all yourself you have some reading to do
https://app.box.com/s/dcym4984vznkj8tpacp6
https://app.box.com/s/mai2335dh4vl43q0efqn

Re: Starter (sprag) clutch replacing

Posted: Fri Jul 03, 2015 10:18 pm
by englishstiv

Re: Starter (sprag) clutch replacing

Posted: Wed Jul 08, 2015 12:23 pm
by Tamburinifan
Crank should be shimmed w 0,30mm freeplay acc to manual.

BE AWARE: You need a real good puller f primary gear,
VERY hard to dismount!
If you do it yourself, it comes flyin off w LOTS of force,
could damage yourself or parts etc 5-10m's away!!!
Professional help safest....

Always clean threads before flywheel mounting
& always use medium loctite. That is, EVERY time...

Re: Starter (sprag) clutch replacing

Posted: Sat Jul 11, 2015 10:35 am
by Kioors
Thanks a lot for the info!

Upon hearing prices of professional overhaul, or a new engine, I decided I will try myself, because for that amount of money I can buy an other 907, which makes mine effectively a total loss. :(

So yeah, a hearthly thanks for all tips and hints. :D (especially the ones that save my body and other motorcycles in the vicinity!)

I've printed out the official manuals, and bought the Haynes book, but now I am going to try and be patient, because I am currently building a new workshop in the garden, and this looks like a job best not done between the freezer and the washing machine.

So, this winter I'll try and keep you guys posted with a fotojournal of progress and disaster. ;)