Evening all, long time no post, hope you’re all well? So, I went to fire up the old 900SS for a gentle bimble in the sun down to Matlock Bath yesterday afternoon, and was greeted by a very feeble turning over. Felt like a dead battery, though it had run fine a few weeks ago when it was ridden 5 miles during a house move. Still, it wouldn’t be the first time I’d left the ignition switch in the “Park” position (and I’m sure we’ve all done that some time or other!). So I popped it on the Optimate and gave it a few minutes (often enough to at least spin it up a bit quicker), but it became even more feeble. So I let it charge up fully and tried again. Just the click of death this time. Checked battery voltage and it was 13.2 V or so, so all good. Fuel pump whirring away like a good un. Anyway, I’m thinking my starter is toast (it is 32 years old, after all). I am going to check the earths, as it was hammering it down during the move and the cable to the starter motor ain’t the most waterproof of arrangements. A bit of standing water in the rubber boot could cause all sorts of mayhem. If it is the motor then my first thought was just to buy one from Electrex World. £120 but currently out of stock. Or I could get a set of bushes from them for about £20 and fit them myself (anyone done that? I did it once on my old 1000 DS, but I asked a grown up to do it for me). Alternatively there are some motors on eBay (new) by Artudatech for only £80. Has anyone tried these? If I’m right in thinking, replacing a starter motor needs the generator cover off, then just three bolts to undo, remove old, slot in new and put it all back together again? Cheers James
Hi James, Before looking into replacing the starter, I would definitely try again with a different battery known to be good (new or borrowed from another bike with no starting issue). As a matter of fact, a battery can be done and still showing voltage after recharge, but no more cranking amps available at start. Have you mesured the tension when you press the start button ? How low does the tension drop ?
Brushes are easy to fit, you can do them with the starter on the bike. A bit fiddly thats all. Ive done a couple
I'd the same problem with a Superlight with the opitmate charger saying you're good to go on you way two weeks ago, i swapped the battery over from another bike and hey presto. So i'm for £71.00 for a new one, life sucks at times but it's all about the ride & nothing else.!
Mine died due to a badly corroded 12v post on the starter , rubber boot water bath did the job. A new set of bushes which came with a new post fixed it.
Identical symptoms when I had a 1200R monster, at the time maybe 8 years old. Was the battery, despite being fully charged. New battery, instant action..
I would also make sure your earth strap between engine block and frame is free of corrosion (where it is bolted on obviously)
If you’ve got a set of jump leads and any battery (car or bike) you can use them to with positive onto the starter connection and negative used as your switch to earth on the engine block and see if it spins up As said before the brushes can be changed in situ but it’s a bit fiddly, generator cover needs to be removed to access all three mounting bolts if you remove the starter
Thanks all, really helpful. I've just nipped out to the garage this lunchtime and done some tests. Battery voltage is 13.2 V. As soon as I turn the ignition on and the fuel pump starts (light off) it starts to drop very rapidly, down to 12.3 V (I didn't wait to see how low it would go). That points to a duff battery, right? So I hooked it up to my Multistrada which was putting out a healthy 14.4 V with the motor running, pressed the starter and... nothing. Points back to the starter, right? That said, my jump leads are car sized and the terminals on the battery (Motorbatt, about 6 years/ 4,500 miles old) are quite small and tricky to get to, so it's possible I didn't have a good connection between my crocodile clips and the battery posts. Will try again this evening. Will also check the battery post/boot for water and corrosion at the same time. Desmoquattro and Bumpstart - changing brushes in situ: I presume it's a case of disconnecting the starter cable, then undoing the two bolts in the end of the starter, then the end cap comes off allowing access? Obviously the oil lines to the oil cooler would need to come off, and even then the access to the bolt closest to the block looks tight. Is that the fiddly bit, or the changing of the brushes themselves? Cheers James
From memory when I did mine on the bench getting the cap back on was the fiddly bit, I didn’t try an on the bike swap.
Hi James Changing the brushes is situ is all a bit fiddly, but there’s nothing to lose if you can’t access it as you can easily remove the generator cover to drop the starter out if you can’t do it all with it fitted. Whatever method you choose, when you remove the starter power cable there’s a narrow hexagon underneath the cable on the power cable stud that should be held securely when undoing or replacing the nut. I made up a narrow holding spanner from a piece of flat steel, from memory I think it’s 10mm. After assembling the power cable I lightly smear some copperslip over it to prevent corrosion under the boot
If someone could confirm, but if you take the generator cover off I think you get some oil leakage, I don't think much but if you are doing it somewhere clean, it might not be good. Obviously rear stand would be better than side stand and I think if you can support the bike safely the other way you might get away with out dropping oil level slightly. Or just have something ready for any oil coming out. Cheers Gaz
In his book, LT Snyder recommends using a rear stand and sliding a small bloc under the stand’s left wheel to slightly lean the bike on its right. That way, no need to touch the oil, which will stay in the motor, when removing the left side cover. I have not tried this myself (yet), though.
Hi Gaz The easiest way is to just drain the oil into a clean container prior to removing the cover then replace it after the refit If you’re removing the generator cover you’ll need to make up a simple puller to draw the cover off the crank end and make sure that all the retaining screws have been removed, check for the ones lurking under clutch slave and drive sprocket area
Cheers guys. I had another go at jump starting it last night off the Multistrada, but no dice. I've pulled the boot off too and though it did have a bit of murky brown water in it, the actual bolt, electrical connector and nut/washer were pretty clean, so I think I'm ruling that out too. The frame earths look good as well. I think I'm leaning towards the starter as being the probable cause. I have found a good "how to for in situ brush replacement here https://ducatistbike.wordpress.com/2016/02/15/working-on-the-starter-st2/ and it doesn't look too bad, once the oil cooler lines are out of the way. I've ordered a set of brushes from Electrex World (£21 inc VAT, plus £5 P&P) and I'll give that a whirl first. They're out of complete starters at the moment, and I'm not fancying the Chinese-made one just yet, even though it's only £80. If I struggle with that then I'll do the complete starter and try to save as much oil as I can! I've got until August to sort it out when we're out at the CBTD Track Day at Oulton Park - whoop! though obviously I'd like to have it on the road ASAP for summer fun. I'll keep you posted. Cheers James
James, Ive done one off the bike, and one on the bike. The one on the bike was on an ST4S, which had more crap to get out of the way first, but once you have it clear, you are right, its two bolts. They are long and go to the front of the stater all the way through. Remove cap and the fiddly part is keeping the brushes in place whilst putting it back together. If I was to do it again, this is what id do. Removing the case is more work, and I have confidence the brushes can be done by yourself easily if you have spannering skills. This doesnt entirely rule out other issues, that battery voltage is a little low. Loadtester would be best bet. Good luck
You are right, the battery voltage is suspect, though I would have thought that jumping it would prove that. I have ordered a new battery anyway - if it turns out not to be that, well, I'll have a spare on the shelf for the day that it is that! Thanks James
If it’s already ordered, then I’d put the new one on the bike and keep the used one on a trickle charger for light side duty. I use my old acid batteries (replaced by LiFePO4) to power diagnosis tools and test various things. Always handy, if kept charged.
OK, so it’s definitely not the battery, and now I have a spare! Always handy as you say Guillaume. When the brushes turn up I’ll find out just how fiddly it can be… Wishing I had a bike lift now! Cheers
I thought i was going to have to do this the other week, but as it happens it was a flat battery (thanks MoT station, for leaving the fuel pump running for an hour). However i did have to refurbish the starter on my 748. I removed the whole thing, good job i did as the commutator was badly worn, deep groove from the brushes. Stuck it on my lathe and cleaned it up nicely, then used a rebuild kit to fit new brushes. All good in the end, but iirc the SS and 748/916 use the same part (but happy to be corrected)
