lemans starter motor broken FIXED

[lazlokovacs]

went to start the lemans today and was greeted with the sound of the starter motor turning but not the engine.

a kind of nasty metallic scraping spinning sound


ummmm


broken teeth?

solenoid not working??


excuse my ignorance


it sounds really nasty!

[Chuck in Indiana]

Something is broken. <shrug>  Maybe take it apart and see what it is? That's what I'd do..

[Kiwi_Roy]

Pull it out and post pictures, we can't see it from here.

[guzzisteve]

Pull it off and bench test it, put it in a vice or it may flop around alot and fall on floor.

[wirespokes]

Makes a difference which LeMans it is, and the year. Early ones had the Bosch starter which is quite different than the Valeo that came later.

The starter comes out easily - very accessible. But disconnect the battery negative cable at the battery before doing anything!

[TDF]

My 2000 V11 sport had the exact same symptoms.  Took starter apart found a magnet had come unglued.  Did a little research and there didn't seem to be a reliable fix for regluing the magnet. Replaced the starter for under a hundred bucks with a new one.  No problems since.

TDF

[Rich A]

My 2000 V11 sport had the exact same symptoms.  Took starter apart found a magnet had come unglued.  Did a little research and there didn't seem to be a reliable fix for regluing the magnet. Replaced the starter for under a hundred bucks with a new one.  No problems since.

TDF

This.

Rich A

[rodekyll]

What year, and is it a bosch or valeo starter?

When that happens to me it's not the starter.  It's the flywheel bolts sheared.  So you might want to stick a screwdriver through the timing hole and see if your flywheel is still attached to the crank.

When it happens to most everyone else it's the Bendix/pinion business on the nose of the starter either failing to engage the ring gear or failing to spin the starter.  Pulling your starter and examining the pinion gear will tell a lot.

[lazlokovacs]

will report back

crazy busy week

Its a bosch starter

I have an old Valeo somewhere which I'm gonna dig out

Really hope my flywheel is still in union with everything else!

[Chuck in Indiana]

When that happens to me it's not the starter. 

[lazlokovacs]

ok,

solenoid appears to be performing its spinning the starter function

but not moving the actuation arm to locate the gear on the flywheel/ring gear

is that possible?

Will a Valeo from a California vintage fit a Lemans 1000?

cheers

[rodekyll]

Yes, and yes.  If you are inclined to replace it, this would be a good time. 

I'll let Kiwi Roy 'splain the first yes, but you've got an ancient starter there.  Unless you want the experience of overhauling it for its own sake, you're way ahead in every respect to replace it with a valeo.

[lazlokovacs]

thankyou RK

I made a mistake earlier,

the starter on the Lemans is actually also a Valeo

[wirespokes]

Ok, so it's a valeo. The actuator arm is plastic and maybe it's broken. I've not run into this problem before, and I've taken apart a lot of these starters. It should be pretty easy figuring out what's wrong once in there. If it's not been apart before, there are two pop rivets that need to be drilled out - probably a part of the assembly process, and definitely not needed by us. You'll also need a small torx bit.

Let us know what you find!

If you're not into working on it, send me a PM.

[pehayes]

solenoid appears to be performing its spinning the starter function

but not moving the actuation arm to locate the gear on the flywheel/ring gear

is that possible?

Not possible with the Bosch starter.  The starter motor won't spin until after the solenoid levers the gear forward.  Glad you figured its a Valeo.

Patrick Hayes
Fremont CA

[lazlokovacs]

yeah, already started taking it apart,

actuator arm is intact,

just doesnt seem to want to move when electrically stimulated....

[wirespokes]

If the arm's not broken, then perhaps the solenoid isn't actuating it. But I don't understand how that could be. The solenoid has two functions - actuate the drive gear and connect the battery positive lead to the starter motor. The solenoid, when it sucks in, connects two large copper contacts. So if the starter motor turns, the solenoid is definitely sucking in, but for some reason it's not activating the drive gear. Either the actuating arm is broken somewhere, something happened to the large pivot pin, or the arm broke at the end where it connects to the solenoid. A close look should reveal all.

[lazlokovacs]

the plot thickens

I have the offending solenoid on my bench, can I bench test it in any way?

I have a battery and some jump leads

[wirespokes]

The big terminal where the big positive battery cable bolted on is where you'd clip the positive jumper lead. Put a bolt in one of the threaded holes and attach the negative lead there. When power is applied, the control rod should pop into the solenoid with a loud THWACK!. I forgot to add that the solenoid is activated with +12V at the spade terminal.

But that doesn't tell you if the solenoid is passing current to the starter motor.

Easiest thing would be to connect the solenoid back up - no need to deal with the control arm or any of that - and see if the starter motor is activated when the solenoid pulls in.

[Kiwi_Roy]

the plot thickens

I have the offending solenoid on my bench, can I bench test it in any way?

I have a battery and some jump leads

Just be aware the solenoid will pull 45 Amps while it's pulling the gear into place so use a decent wire like #14 and be positive with your actions when you make contact with the spade connector, you will get a fair size spark as you break the connection, that's normal.
The solenoid is a powerful electrical device, it stores a lot of energy.

[wirespokes]

I've never measured the solenoid's draw all by itself. Never would have guessed it was as high as 45 amps! I do know the starter can draw 1-200 amps when turning over the engine. Haven't checked the Valeo, but I think it's less than a Bosch.

Just thinking about it, I don't see how the solenoid could draw that much current considering the small spade terminal and light gauge wire for the activation circuit. The large threaded terminal where the battery-positive-cable lead attaches isn't for the solenoid's use, but the starter motor itself. The solenoid is just a heavy duty electro-magnetic switch (relay) - it switches on the starter motor by connecting the battery to the starter, plus engaging the starter gear.

[Kiwi_Roy]

I've never measured the solenoid's draw all by itself. Never would have guessed it was as high as 45 amps! I do know the starter can draw 1-200 amps when turning over the engine. Haven't checked the Valeo, but I think it's less than a Bosch.

Just thinking about it, I don't see how the solenoid could draw that much current considering the small spade terminal and light gauge wire for the activation circuit. The large threaded terminal where the battery-positive-cable lead attaches isn't for the solenoid's use, but the starter motor itself. The solenoid is just a heavy duty electro-magnetic switch (relay) - it switches on the starter motor by connecting the battery to the starter, plus engaging the starter gear.

Have you ever heard the term Starts Interrupts?
Its caused by exactly that the light gauge connectors, contacts and the little bitty wires.
Yes, its the "plus engaging the starter gear", that requires the heavy current, thats a huge task for a simple electromagnet.
That's why it's not a simple electromagnet, it's two coils one of heavy wire that pulls around 40 amps and another of lighter wire that draws ~10 Amps
Or at least it would if Luigi would wire it right.

I don't know the exact point the solenoid stops operating altogether to give you the dreaded click but it's in the range of 25 - 30 Amps

Just by replacing the small wire from the relay to the solenoid on my 07 Griso it made the solenoid operate 3 x as fast.

[lazlokovacs]

trying the electrical test just gets me  a big spark and no discernible movement on the solenoid...

But the starter was spinning when it was on the bike

Flywheel is all fine and dandy, bump started the lemans and rode it home yesterday, nice to shed a bit of weight off the old bird

[wirespokes]

Roy - now you've got me curious. I think I'll have to measure the current on that solenoid activation lead.

I know it's a heavy duty relay, but had no idea it required THAT much current!

Lazlo - That's really odd the starter would spin without the solenoid working. Doesn't make sense, unless the solenoid is stuck in the 'on' position. The switch delivering power to the starter is only ON when when the solenoid is activated.

It sure sounds like the solenoid is the culprit.

[Kiwi_Roy]

Roy - now you've got me curious. I think I'll have to measure the current on that solenoid activation lead.

I know it's a heavy duty relay, but had no idea it required THAT much current!

Lazlo - That's really odd the starter would spin without the solenoid working. Doesn't make sense, unless the solenoid is stuck in the 'on' position. The switch delivering power to the starter is only ON when when the solenoid is activated.

It sure sounds like the solenoid is the culprit.

How do you plan on measuring it, do you have a high speed Ammeter?
It does require THAT much current. you might just get it to pull in with 20 Amps but it won't be reliable.

A typical Guzzi relay like the Omron G8HN used on bikes around 2000 is rated for 100 Amps Inrush Current

I assume by now you have pulled the end off the starter to check the magnets are in place, what was the cause of the grinding noise?

Answering for Lazio, Since the heavy current coil is in series with the armature it might spin without pulling in, it would accelerate quite slowly I suspect. A Valeo at least, I doubt a Bosch would.

BTW
I found the notes I took on the Valeo of my 2001 VII Sport, the two solenoid coils measured
Holding Coil  1.05 Ohms, by Ohm's Law at 12 Volts that would pull 11.42 Amps
Pull in Coil     0.25 Ohms, by Ohm's Law at 12 Volts that would pull 48 Amps
For a grand total of                                                                    59.42 Amps, could easily go over 60 with a little more Voltage
With the wimpy Guzzi wiring though I measured only 37, this is without any rotation yet.

Its all this current that causes "Startus Interruptus" it only takes a fraction of an Ohm somewhere along the way and all you get is "Click, Click"

Once the solenoid closed the main contactor and it started to spin over that big old DC3, the current drawn by the motor varied from 160 to 200 Amps depending on where the engine was in it's cycle.

[wirespokes]

Thanks for that Roy. That's all very logical and makes sense now.I was thinking of using the clamp-on Amp meter, but don't know that it would catch the peak. Looking at it from a resistance standpoint is a good way to go about it.

You've got me curious now how the coils are internally connected. You're saying the Valeo armature is powered up from the Heavy Current Coil and not a set of contacts, closed when the solenoid is drawn in? I just assumed the Valeos were like all the other starters I've worked on.

When my T3 starter acted up (click, click, click...), jolting it would make it go. Pulling the starter (Bosch), dismantling it - finding nothing wrong, put it back together and remounting fixed the issue. I'd assumed it wasn't making a good contact with the bell housing. So it makes a bit more sense that a slight bit of oil on the mounting could provide enough resistance to prevent the starter from working.

Thanks again for clearing that up for me.

[Kiwi_Roy]

It probably wouldn't hurt to go over the starter sequence.
As I see it there are 4 steps to the starter Operation
Step 1 engage starter gear
Step 2 Crank
Step 3 Disengage starter gear
Step 4 back to rest

The first sketch shows what's likely to happen on a bike with pristine wiring.




The second sketch shows an older bike with tired wiring


This sketch shows how to put a new spring in its step


This is just an overall diagram

[Chuck in Indiana]

Thanks again. Saved in my "Roy's Guzzi Stuff" file. 

[Kiwi_Roy]

If you were ever curious about what's inside the solenoid.
Here are the two coils, I suspect I'm pretty sure, I may have lost count and they are both the same number of turns.
The 16 Gauge coil is wound on first where the diameter is quite small
The 20 Gauge is wound on top.



The strength of a magnetic coil is Amps x No of Turns
So using 40 and 10 Amps for example
The light coil is 300 x 10 = 3,000 Ampere Turns
The heavy coil is 250 x 40 = 10,000 Ampere Turns
So in step 1 the combined strength is 13,000 Ampere Turns while pulling the solenoid and gears into place.
Step 2 it drops down to 3,000 Ampere Turns while cranking, just enough to hold everything in place
Step 3 it drops to 450 Ampere Turns (almost equal strength and opposite)

If someone has an old solenoid laying around how about counting the turns for me

[wirespokes]

Thanks again, Roy! Excellent data.

I can't believe that some bikes would run 40 amps through the ignition or start switch. That's crazy!