Starter problem

Dellortoman

Dellortoman

Hero member
Location
Tasmania, Australia
Last weekend I went for a ride on the Jota. Bike went OK but starting was a hit-and-miss affair. A couple of times it stubbornly refused to start and I had to push-start the bloody thing.

On the occasions when it wouldn't start, all I'd get was a click from the starter relay and the neutral light would go dim, indicating that either a hefty current is going somewhere or I had a dodgy battery connection.

Starting has actually been a bit iffy for years. I'd occasionally get a refusal from the starter motor when I hit the button. But it's been doing it a lot more often recently. Last weekend it really gave me the shits enough for me to do something about it.

Today I got around to doing some diagnosing. Started working from the battery. Terminal connections all nice and clean and done up tight - no problem there.

Next was to check the relay. Took it all apart - you have to drill out the rivets in the relay case to do this (replace them with M3 bolts). Solenoid works fine and the contacts looked clean so no problem with the relay, but I gave the contacts a bit of a rub with a wire brush to shine them up a bit more while I was in there.

Then I turned my attention to the starter motor. Took it out and gripped it in the vice to give it a test run. Put the battery on the bench next to it and hooked up some heavy leads. Motor spun up as expected. Tried it a second time and ...  nothing! Just a lot of arcing of the electrical lead as I touched it on the battery terminal, indicating a heavy current draw, but no action from the motor. With a bit more fiddling I got it to spin once more, then nothing again. 

So it seems there's an intermittent short circuit in the starter motor. I took it apart for a look and there was nothing obvious from a visual inspection, so the short must be somewhere inside the armature winding.

I called my mate Andy the auto electrician and he said it's not uncommon to have an intermittent short in the armature. I'll drop it off with him tomorrow and he'll check it. If I'm extremely lucky it'll be something he can fix, but the most likely outcome is that I'm up for a new starter motor.

It's a Bosch starter motor for a 1976 3CL. Anybody got a good one lying around?

Cheers,
Cam
 
I had similar symptoms with a fan motor on my Audi.
I took it to a local auto-electrician and within 2 minutes on their 'special' rig they diagnosed a knackerd slip ring (he may have been referring to the commutator though).
The thing that gave it away was the motor wouldn't turn when placed in a certain position, just a nudge around to a different spot and away it went.
They said they could fix it but it was nearly as cheap to get a new motor.

If it is this it might be economical to get your starter fixed up, you never know.
 
Donkeys years ago I had a similar problem,the Auto Sparky connected up the starter motor and held it against a softwood column in the workshop,it did a good impression of a Router.He was checking how much guts,technical term,it had.Old school place long since gone,family business since the 1920s.They now run a Battery World Franchise.
 
Cam,

I can supply new SJCA starters as used on the RGS models, straight replacement for the old Bosch.  ?390 including drive gear, + postage of course.

piet
 
Cam I have got a couple of starters here but they are probably a lot worse than yours as a matter of fact they'r f----ed. I found out what caused my latest failure on the 120 Jota as a couple mentioned the three little screws on the back of the clutch had worked loose this let them contact "well nearly weld themselves against the freewheeling gear :o :o :o must have been a few sparks going on in there
 
Piet,

Are the SJCA starters ok for a 180?  I thought they were not as strong as a Bosch (or geared differently or something I don't understand....I am not a mechanic  ;) ). There was a nearly new one on the Jota (1200), fitted as it was all he could get new. It barely turned the bike over with a new battery. Fitted the Bosch off the 3c and it spun over like a good'un  :D

Pete
 
The SJCE needs a different cog size (Piet said he included it in the price).

I fitted an SJCE to POP. Fresh rebore and 10:1 compression. No issue with cranking it over.
 
Pete,

It is not entirely unknown that the SJCE starters also give up the ghost... eventually.  :D  Just as prone to as the Bosch.

Plenty strong to spin any 180.  IIrc, the Bosch is rated at 1/2hp (pre kW times, shows how old it is), the SJCE at 400W, which works out about the same.  Actually swapped the SJCE from my RGS to the 3C when the Bosch was getting weak, just stuck that in the RGS once it was fixed, been like that for years now.  As I said, striaght swap.

As the starter is used in several Laverda applications (RGS, Atlas, 668), each application calls for its' appropriate gear.

piet
 
Do you mean the brushes Lothar? I checked them and they're OK - plenty of length in them and all making good contact.

Piet. Thanks for the offer of a new SJCE. I'll see what the auto electrician says first. ?390 is a bit painful but I might have to bite the bullet and fork over the Euros if the electrician declares my motor deceased.

I notice that Voldemort (he who must not be named) has a used Bosch motor on eBay with a starting price about half of that much, but there's no "Buy it Now" option so it could end up at ?390. It has a fresh coat of paint so it must be good  :D    http://www.ebay.com.au/itm/140927311243?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648

Cheers
Cam
 
Thanks guys for the SJCE info.

Grant - you may have given the answer. Perhaps my SJCE starter had the wrong size cog. I wonder if I still have it? I will see if I can find it over the next few days and compare cog size to the Bosch.

cheers

Pete
 
Thanks Stefan. No visible tracks on the windings. Everything looks good. Only problem is it doesn't work.

My auto electrician mate (Andy) is old school. He used to rewind motors by hand (I know of one Laverda Bosch starter motor he re-wound some years ago) but he reckons he's getting too old to do it now - got arthritis in his hands and his eyesight isn't what it used to be.

If the armature in my motor is fucked, I might even have a go at rewinding it myself. How hard can it be, and what have I got to lose? (apart from my temper)

Cheers,
Cam
 
sfcpiet said:
Pete,

Wrong cog won't let it mesh properly with the freewheel idler.

piet
Click to expand...

Piet,
Can't be that then, as it meshed fine. Just really struggled to turn the motor over. I checked all the connections & cables. Same. Put the Bosch on and it spun over real fast. Hmm?  Must find it and investigate.

Cam - good luck with the rewind......these days, I have enough trouble winding my watch  :P

Pete
 
Might want to check that the brush holders haven't rotated around their mounting rivets, they did on my RGS, presenting similar symptons to those you describe. Fixed by twisting the holders into the correct position (right angles to the commutator) and aralditing in place. Been working for twenty years.

HTH

Terry
 
That's interesting Terry. Never heard of that happening before. I didn't actually check the alignmnet of the brush holders, but nor were they obviously out of alignment. I can't check it now, the starter motor has gone to the sparky.

Cheers,
Cam
 
yes, meant to say "brushes"  :-[ getting memory problems sometimes lately, should work less and relax more...  :-[

the brushes on my SJCE looked good, too, but one - although looking as if it had - did not have proper contact. new bearings, a worked over rotor and new brushes and off I went. Overhaul at OCT was something like 130? if I remember right.

Might well be though that one (or more...) of the cables have an insulation issue. You (or the repair service) can measure that. I have a company in Germany that did a full service on my Bosch starter some 5 years or so ago. including new (and some more...) cabeling, new bearings and brushes. It came out so nice that the 1200 high compression engine now starts half a second after you pressed the button.

Cost was around 160? fully serviced, but that is as said some years ago.

HTH
 
Andy the auto sparky said my starter motor has a short circuit between the stator winding and the case. It has some pink goo painted on the stator that's supposed to insulate it, but the paint film has broken down and become conductive. I dunno whether the pink stuff is original or whether some previous owner has put it there. He reckons he can fix it by soaking the stator in acetone to get rid of the paint and inserting a thin layer of paper insulation between the stator and case. It has to be thin as there is bugger-all clearance between the stator and rotor. He said he could still buy new windings for these motors up until about 2003 when Bosch stopped making parts for them.

He reckons he'll have the refurbished starter motor back to me before Easter (I have the bike booked on the boat to go to Broadford at Easter). But he's notoriously bad at meeting his own deadlines, so I borrowed the starter motor out of Hal's 3C (which is in mothballs) just in case Andy doesn't get it done in time. It spins the engine over twice as fast as mine ever did. My starter has always struggled to crank the engine so must have been sick for a long time. I'd always thought it was slower to crank than other triples because of the HC pistons. Does that qualify me for DHOTM?

Cheers,
Cam



 
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