[VnsM900]

Hi all,

Sometimes my monster 900 wont start. It feels like the little sprocket is not being moved towards the flywheel.
When this happens, I put it in 2nd gear, push the bike just a little bit, and then it always works again. Untill it doesn't, one day..
Seems like there is something stuck or so.

The bike has a new battery and thicker cables mounted.

Can this be the solenoid? Or is it something that can work again after cleaning it?
Not sure what part of the starter motor causes this failure..

Hope somebody with more knowledge can tell

 

[QLDs4]

It feels like the little sprocket is not being moved towards the flywheel.

It's not a car, the starter gear is in constant mesh with the driven gear.
Sounds like your sprag clutch is dieing.
Sprag ( clutch one way ) is 22 in this diagram but you'll need to get the driven gear 20 off to get at it.

STARTER MOTOR & IGNITION for Ducati Monster 900 1998 # DUCATI - Online Genuine Spare Parts Catalog

www.bike-parts-ducati.com

Ready for the bad news?
The parts diagram doesn't show this BUT the flywheel over laps the driven gear.

I haven't had to replace one but I think you'll need the generator outer half and maybe the flywheel off to access it.

 

[chris900ssie]

The Sprag clutch is in the back of the flywheel. Its not a complicated job. You will need a deep Socket for the flywheel nut, A flywheel holding tool and some Gasket sealer for the alternator cover. Its nit more than an afternoons work if you are doing it for the first time and taking your time to do it right. You will also have to drain the oil or lean the bike over to the right.

The Ducati part is expensive (or used to be 3x the cost from BMW or KTM) however .....

Ducati 70140071A
BMW ENA57177
KTM 58440026000

Both the BMW and the KTM parts need to be either installed backwards or have their sprag lobes reversed but work perfectly

 

[chris900ssie]

Oh and red Loctite for the flywheel nut, You are supposed to renew them but I have also re-used them without issue XX,000 Km later.

 

[VnsM900]

Thanks a lot for the explaination guys! Really helpfull! Seems like a good reason to get the bike in the living room for a few hours

 

[chris900ssie]

Here you can see the flywheel and the Sprag or Starter clutch is the third part in from the right. If you are unlucky the 4th part, the cog, might also need to be replaced if scored or damaged. Fingers crossed not. I've never had to swap one out so far.

 

[.Kiev1981]

Cool


Sent from my iPhone using Tapatalk

 

[VnsM900]

@chris900ssie I think I need to have that part laying around to make sure the job will succeed. Do you know the partnumber of the part that you point to?

 

[chris900ssie]

What year is your bike?

 

[VnsM900]

1999, carb version

 

[chris900ssie]

Page 50, part num 20. Yes its the injected bike but the parts should be the same

You can always double check using the Stein Dinse website, they have a really good parts list

 

[VnsM900]

Thanks a lot for your help! I can work with this

 

[diwabas9]

Smiles


Sent from my iPhone using Tapatalk