starter problem! S4

[McMONSTRO]

Hi all, well its time to get the bike out but Ive hit a problem! put a new battery on as the last one seemed a bit tired,and its just the same so had them checked out and they are BOTH fine, so took off the starter motor which meant removing the left hand crankcase to get at the bolts! The starter seems fine, good voltage etc, so put it all back together and now the starter just spins! its not engaging! Have I missed something?

Hoping to get down to Arrow Mill for the weekend but this might stop me, any Ideas?

Cheers McMonstro

PS might be a day or two before I get back online as Im at my girlfriends most of the time now and no PC there (yet)!

[Scotty]

thers a starter motor clutch thing but i dont know anything about it

[PaulS]

Was the stater just spinning before you took it apart or is this new? I recently had a problem getting my S4 to start which I put down to the battery as, although my Optimate says it's OK, it would start fine when jumped from my car but not from the bike's own battery. I got a new battery but the bike still wouldn't turn over at all, just clicking from the solenoid. After much swearing and taking apart of various bits it turns out the new battery was duff too! Another new battery later and it's starting fine. Otherwise it sounds like the starter motor clutch (aka sprag clutch) as Scotty says - nasty!

[McMONSTRO]

Yep! Thats at the back of the generator (I think) the starters spinning, which is spinning an idler cog, which is spinning a larger cog at the back of the generator rotor, and thats where the movement stops! Looks like some sort of electro/mechanical clutch device! Wonder if there is a oil/water level sensor which stops this happening if the levels are low? Because all the fluids are covering my patio now! Because the drain tray wasnt big enough!

Another job to do!

[McMONSTRO]

Paul S, before I took it apart it just sounded like the battery was duff, but both were fully charged and tested and found to be OK, in fact the original one was better than the new one! Now the starters just spinning, even tried using a car battery and its still the same!

[PaulS]

You could try rocking the bike backwards and forwards whilst in gear to see if it persuades the starter clutch to do its stuff. May not do any good but easy to try. I think the starter clutch is purely mechanical (works by centrifugal force I think) so I doubt if the lack of oil would stop it working. I've heard these clutches can be troublesome on Ducatis. I'm gradually getting the impression that Ducatis don't like being left unused for too long at a time.

[Starter Sprag]

The starter sprag / clutch, is designed to compress (torque) when the starter button is pressed, it is also magnetic, and is NOT affected by any fluid level

Unfortunately it is behind the alternator, you will need to heat the nut up gently in order to break down the thread-locking compound, and to avoid stripping the fine thread

A common cause is a loose sprag-spring, it can sometimes stretch, preventing the bike turning over

A simple solution is to remove the sprag-spring, and trim / shorten it's length, and refit it

I have kept this brief, because it is not a simple task, and requires careful removal-refitment

If you want a detailed blow-by-blow instruction I will provide it, but first try to establish, nothing else is causing your problem

[Shauns4]

If the pinion/idler/sprag clutch gear are all turning then its the sprag clutch which isn't working.

Have you had the bike running by bump starting it? This should get some oil into the clutch and free it off, if this doesn't work I would take it off and replace it.

If the flywheel hasn't been off before you don't need to heat the nut as Ducati do not use loctite but the nut can be pain to loosen without the Ducati flywheel locking tool unless you have an impact gun.

If you decide to take the flywheel off make sure you do let the thrust washer drop behind the needle roller bearing when you assemble the flywheel back on the shaft!

The sprag clutch also has to be fitted in a specific orientation.

The haynes manual for the 916 gives very good instructions for general engine work.

Shaun

[Shauns4]

This is also useful

http://www.nicholsmfg.com/flywheel-inst-4.html

[McMONSTRO]

Hi all, thanks for all the advice! Back home this weekend so off to try the bike again! Spoke to JHP at coventry and after a few tests found that some how Id managed to get the starter motor running backwards! Stripped it down again,rebuilt it and now alls well with that, so that rules the sprag theory out. checked all the voltages and alls ok, charging etc but it still wont start off the bike battery, the original or the new one, put on a car battery via some jump leads and she fires up straight away, so I guess its time to buy ANOTHER battery! Some one suggested that the timing might be too advanced but as the bike runs OK once its started I reckon that idea might not be the problem! Hopefully be fixed for next weekend so ill keep my fingers crossed!

Cheers, McMonstro

[Shauns4]

confused, there is only one connection to the starter motor so how can you get it to run the wrong way?

[Scotty]

the earth goes through the frame like majik

presumably you trashed bothe batterys with the starter wired wrong ~:?

[clockworkorange]

Check the relays under the seat as well - they have a tendency to pack up.

[bod]

Sounds like a typical battery fault but if you have tried a new one?
Don't know how old yur bike is but could also be high resitance in the wiring/solenoid....Try a one end of either jump lead between battery posative terminal and main starter wire this will rule that out.The starter will earth through the bolts attaching it to the engine and then frame I guesss,so check these and the earth between battery and frame.

[McMONSTRO]

Christ knows how the starter motor ended up running backwards but its fine now! All the wirings been checked by my "man with a meter" and he cant find any problems, did the bypass trick with the jump leads and that ruled that out, earths cleaned etc, even changed the ECU to see if that would help? Nope! just the same!
So Ive took the "new" battery back to the local bike shop and there "checking" it, hopefully it will be replaced! Only thing that is certain is that by jumping a car battery to the bike it starts straight away, use either of the bike batterys fresh off a charger and its a no-go!
Time is now running out for the weekend........bummer!

Thanks all for the tips and advice, McMonstro

[Scotty]

get practicing that bump start ;)

bwuhahahahr

its easy with a bit of practice

[McMONSTRO]

Tried that in 03 at WSB's at silverstone when I left the lights on in the bike park, had to go begging to the RAC/AA in the end coz that didnt work, my mate lost plenty of weight pushing me tho!

Good news is Im getting a BRAND NEW battery to replace the last one off the local bike shop (Honda dealer, coz theres no Ducati dealer for miles round here) tomorrow, so fingers crossed, along with everything else, I should have a result!!!!!!! If not????? Well lets hope that does'nt happen!

[McMONSTRO]

New Battery on! FIRED UP FIRST TIME! YIPEE!
The moral of this tale must be "BUY THE BEST BATTERY YOU CAN, AND IF THAT DOESNT WORK TRY ANOTHER!"
This would have saved many hours head scratching!

Thats the good news, the bad news is that after succeding to get the bike up and running OK for this weekend, and a trip to Arrow Mill for the "Monster Weekend" I now have to go to the Isle of Man for work for a week on Saturday! And I cant get the bike in the van either! (Citroen Berlingo Im told) Ah well at least I can look at some great biking roads, even if I cant ride em!

Hope you all enjoy the weekend and the weather stays good! Ill look forward to seeing all the pics on my return!

ENJOY! McMonstro