starter issues a convoluted tail

[pete mcgee]

Over the last 12 months or so the mk3 lemon has had an issue with starting.
Push button, either get a click at the starter motor and no start, or you can hear the start relay click and stuff all else.
Bit by bit I have been working on this, services the starter motor, new brushes, new bushes, new solenoid, new start relay.
Problem still there intermittently.
On top of Mt Glorious last week it wouldn't start at all, pyxh start down the hill from the cafe resulted being parked on side of the road.
Opened up the start switch block and the bloody button and spring departed at high speed, ah ha thinks I that's the problem, well partially.
Shorting the contacts didn't do anything so I ended up jumping the battery input to the starter motor to the spade connection into the solenoid where the wire from the start relay connects.
It started.
Got home and changed the start switch block, see dear all those bits did come in useful.
Trail started fine, problem solved.

Not

It was back to intermittent starting after a breakfast run, 6 stabs of the button, 6 clicks, call it filthy names started on stab 7.
Dropped in to see the sister, no starting at all, wtf etc, jumped the solenoid again and went home.
Ran a multimeter over everything, pulled fuses and cleaned contacts, load tested battery OK, 7 volts at the solenoid from start relay ah ha.
Looked at the wiring schematic, the convoluted path the starter circuit takes is mind boggling long on very thin wire.
Final fix (I hope), disconnect factory wiring from the power in on the start relay and between the solenoid input and rewire.
4 mm sq wire from batt positive to start relay, 4mm sq wire from start relay to solenoid input = 12.5v at solenoid when start button pushed.
I sincerely hope that's it as I've run out of things to fix/service/replace.
So what was the problem?
Entropy
32 year old wiring, fair wear and tear, dirt and the Italian way if designing a start system 4 times longer than it needs to be.
If I'm back bitching after this mornings ride, I'll be looking for more ideas, until then Mt Glorious beckons.
Ciao......

Update, brilliant ride, great weather, 5 starts with absolutely no issues.........fina lly.

[swooshdave]

On my bike sometimes I'll hit the button and the starter will spin but not engages. Usually by the third time it works and the bike starts. After 80k miles I'm sure the starter is getting tired. Is it the starter or ring gear that will fail first?

[Green1]

Sometimes when checking wiring you may have to put a load on the wire,ie a halogen bulb,run power to one end of the wire and ground after your load/bulb,bulb lights its ok.A wire with a partial break in it will pass a continuity check ok with a multimeter as just a couple strands of wire are needed but can't carry enough voltage to turn on the circuit

[Kiwi_Roy]

Shorting the contacts didn't do anything so I ended up jumping the battery input to the starter motor to the spade connection into the solenoid where the wire from the start relay connects.
It started.

So you solved the problem, classic case of Startus Interuptus

At 7 Volts the Bosch solenoid is pulling around 22 Amps and you have just on 0.25 Ohms of resistance between the battery and the solenoid
The Bosch solenoid would really like to have about 50 Amps to pull the starter gear into mesh.

Great troubleshooting by the way

Now I just need to figure out what bike you are talking about. Mk II Lemans I think    Lemon, I should have guessed 

Moto Guzzi, making electricians out of riders for over 90 years

[oldbike54]

 Had a dog with a convoluted tail , the Vet put a splint on , straightened it right out 

 Dusty

[rodekyll]

There's a species of housecat peculiar to the inbred island we live on that's easily distinguishable by their tails.  The tails start out normal and end at a right-angle.  It's been speculated that lack of breeding variety in the first century or so of settlement here caused it.  I say getting your tail caught in the door visits itself unto the third generation and beyond.

[oldbike54]

 Do the cat's tails all volute in the same direction?

 Dusty

[rodekyll]

I have not seen them all.

[swooshdave]

So you solved the problem, classic case of Startus Interuptus

At 7 Volts the Bosch solenoid is pulling around 22 Amps and you have just on 0.25 Ohms of resistance between the battery and the solenoid
The Bosch solenoid would really like to have about 50 Amps to pull the starter gear into mesh.
[/i]

What's the best way to insure you are able to provide 50 amps?

[pete mcgee]

By running a heavy enough wire directly from the batt positive to the start relay and then on to the start solenoid.
Clean the earths, on a tonti remove the main earth from the frame and connect to the gear box.

As to your previous question, its usually the starter motor that fails first.
Is yours a Bosch or Valeo?
The Bosch is easy enough to remove and service yourself or have a auto elec do it for you.
Mine is original, 32 years old, I think I've serviced it twice, last time it got new brushes, armature bushes and a solenoid, good clean and lube.
Valeos, I know nothing about.

HTF did we get onto cat and dog tails?
Ah my fault, I can't tell a tale from a tail

[oldbike54]

 'S OK Pete , mostly we were a bit bored 

 Dusty

[swooshdave]

By running a heavy enough wire directly from the batt positive to the start relay and then on to the start solenoid.
Clean the earths, on a tonti remove the main earth from the frame and connect to the gear box.

As to your previous question, its usually the starter motor that fails first.
Is yours a Bosch or Valeo?
The Bosch is easy enough to remove and service yourself or have a auto elec do it for you.
Mine is original, 32 years old, I think I've serviced it twice, last time it got new brushes, armature bushes and a solenoid, good clean and lube.
Valeos, I know nothing about.

HTF did we get onto cat and dog tails?
Ah my fault, I can't tell a tale from a tail

I shouldn't feel guilty about hijacking now that ya'll are talking about animal tails.

It's a Bosch, although I've heard the Valeos are supposedly better in that they draw less.

I'm sure this winter the starter will get pulled and loved.

[pete mcgee]

Yea, from what I've read and heard the Valeos draw slightly less current, spin faster, but they are repaired by replacement.
I prefer the Bosch because I can repair it to a certain extent and all the bits are still available.

Cheers

[rodekyll]

I'm torn.  The Bosch weighs 2x the valeo (or more), draws 2x the current and lasts 12x as long.  The Valeo spins up faster, uses less power doing it, and dies a thousand deaths.  So my choices are to cook my battery and switchware or continuously replace starters.  I'ts like comparing apples to operating systems -- you can choose your evil, but you only get evil choices.

[pete mcgee]

Well this is my 3rd start problem in 29 years, the others have just required a new solenoid or a clean and lube of the starter. 32 years out of a set of brushes ain't bad.
And let's face it if all else, fueling, timing, valve clearances and compression are within spec the bike will start in under 5 seconds, (unless its on a bmw airhead motorcycle on a winter morning, then park and wait till lunch) so its not working that hard or depleting the battery beyond what its designed for.
Bosch or Valeo, I prefer Bosch, they were made back in the day that engineers not bean counters called the shots.

[rodekyll]

Mine started once as soon as I turned on the ignition.  Remembering the incident, I'm inspired by its enthusiasm!     I'll tell the rest of that story later*. 

And a buddy with that same airhead carried a can of starter fluid with him.  He claimed it was for the bike.

But you're right.  My efi stuff usually take off within the first five compression cycles cold or hot (provided I do my pre-start ritual peculiar to each bike), and I don't use fast idle controls on either of them.  My problem is that I run Converts.  So I'm a bit anal about starters. 

I was out today trying to get mine started to see if my new guzzidiag cables are counterfeit or legit and my valeo starter catches for a cycle and then spins free.  Sometimes it won't catch the ring gear at all -- just spins.  It sounds like the motor is good but the solenoid is not holding itself in.  It was on the trike.  Not wanting a sucky starter along on my trip, I moved it to the Rodekyll.  I'd forgotten about it till today.

The problem followed the starter, and the one I swapped to the trike works good, so it's not my wiring.  I changed the battery anyway and mix-n-matched solenoids from the other dead valeos I have lying around (cleaned them of course).  The symptoms remain the same. 

Then I did the Bendix version of musical chairs to the same effect -- spins like a big dog but doesn't want to engage the enemy.

I've only got one good armature, and the spinning doesn't seem to be the issue -- holding the engagement is the issue.  So I'm not worried about that or the starter back end.

Over the weekend I'm going to try one more time with my most cleaned up and least hated solenoid and Bendix.  When I'm convinced that I can't whip up one useful starter out of three dead ones (Bosch would NEVER treat me that way!) I'll wait till I get south where the starter Pete sent is stashed to check out the guzzidiag.  I can't deal with it right now.

*spoiler:  It involves sand, a long side stand and new shorts.

[CalVin2007]

 David-
     It sounds like the one-way roller clutch in the starter drive (some folks refer to it as a "Bendix")is worn out. The rollers get flat spotted and don't lock solidly in the drive direction,which allows the starter to spin without turning the flywheel even though the actual drive pinion on the starter is engaged with the flywheel. Maybe?

  Terry

 

   

[pete mcgee]

Rodekyll,
A comic tragity or a tragic comedy?

Dave,
Sounds plausible, from his description it does everything but drive.

[rodekyll]

I dunno which.  But when I whine about it I like to whine in an interesting way.

I haven't gotten to the valeo yet.  I'm held up on the Isuzu truck's lift hydraulics.  The motor is like a starter.  It has 4 arcing brushes about 1/4" long running on a smooth slip ring where the commutator used to be.  I don't think it overheated on account of the hydraulic fluid dripping out of it probably kept it cool.  I don't think I'll spin test it.

[Kiwi_Roy]

I'm torn.  The Bosch weighs 2x the valeo (or more), draws 2x the current and lasts 12x as long.  The Valeo spins up faster, uses less power doing it, and dies a thousand deaths.  So my choices are to cook my battery and switchware or continuously replace starters.  I'ts like comparing apples to operating systems -- you can choose your evil, but you only get evil choices.

The Bosch is a series motor, current runs through the field and armature in series. This used to be the motor of choice for traction, railways etc. because they develop massive torque.
This is a very common type, my Lario has a Lucas very similar

The Valeo is a shunt motor (not quite correct because the fields are magnets) these run at a fixed speed, it doesn't develop as much torque that's why it has a planetary gearbox.

Personally I prefer the Bosch type because they are much simpler.

BTW the Valeo on my VII Sport draws more (~170 Amps) than the Bosch on my California II