lemans starter motor broken FIXED

[Kiwi_Roy]

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!

Pretty much every Guzzi since the 60s, they get away with it for a while then it drifts lower as the resistance builds up.

[wirespokes]

Ok - you sold me. I'm installing a relay. Come to think of it now, that's the way the airheads were wired and the right side bar switch wiring burned on the R90 due to that.

[Chuck in Indiana]

Ok - you sold me. I'm installing a relay. Come to think of it now, that's the way the airheads were wired and the right side bar switch wiring burned on the R90 due to that.

Surprise surprise.. 

[Kiwi_Roy]

The start button does have a relay, it only carries 100 - 150 milliamps
It's the ignition switch that has to pass all the current feeding the relay's 30 terminal.
A typical relay normally open contact is rated 100 Amps Inrush, the normally closed 60 Amps because the contact pressure is quite a bit less. I have never seen the specs on an ignition switch but my gut tells me it can't be even 20.
When we do the Startus Interuptus fix we move the heavy current from the switch and apply it directly to the relay.

The only explanation I can come up with for the factory wiring this current through the switch is they think it's only 10 Amps which is all you would see if you put a meter in series with the spade connector because the High current pulse is so quick all you see is the holding current through the light coil. So armed with that information a 15 Amp fuse and little bitty wire seems reasonable.
But if you were to take an Ohmmeter and measure between the spade connector and chassis you will get a reading significantly less than 1 Ohm so how can that be?
This is how I found out Luigi's drawings are wrong, there are two coils not one as he shows.

[Kiwi_Roy]

It turns out the bike is a 1990 Lemans 1000
Carl has a drawing for that
http://www.thisoldtractor.com/guzzi007/schematics/1990_LM_V.gif

I see a possible problem
Look at the starter relay (33) See the brown wire on the lower left terminal, it's fed from a fuse which in turn comes all the way from the ignition switch via another larger brown wire
you will be lucky to get 20 Amps all that way on a good day.
You can see this on a Voltmeter, the Voltage will read 12+ to chassis on the relay terminal but when you press the start button it will dip down, briefly if the starter works or go down and stay down if all you get is a relay click.
 

How to Startus Interrupts proof this wiring.
Take the wire from the lower left contact and combine it with the other wire on the coil upper left, so now its just the coil thats fed from the fuse and ignition < 1/4 Amp.

Run a new #16 feed from the battery thru a 15 Amp fuse to the relay contact lower left now you have a feed capable of supplying whatever the solenoid can draw 45 - 50 Amps and the starter will thank you for it.
A 15 Amp fuse should be sufficient because the high current spike is so short.


Of course if you want to keep the wiring original you could pull the switch apart, clean the contacts, polish up the fuse connections, tighten the jumpers and it might operate for a few more years but that will never come close to the speed of the starter with a decent feed.

Note: I'm ignoring the fact the starter solenoid is drawn wrong, only 1 coil not connected

Another weird side effect of this wiring, if you have your foot on the rear brake it probably has trouble engaging the starter.

BTW as a sparky I cringe when I see the unfused ignition switch feed (red wire), on my older bikes I added a 40 Amp Main Fuse at the battery just in case there is a short somewhere it will save the bike from a total meltdown.

[lazlokovacs]

Roy, your diagrams are really helping me out

thank you

Swapped in my working Valeo from my old Cali and after a day it was slow turning and then click click click

Will investigate this weekend

[wirespokes]

About a week ago I came home from Salem (50 miles to the south) on a cold and windy night. At the freeway exit eight miles from home, the engine died and the starter barely turned the engine over. A couple more tries and it was click click click. Pushed it off the road and down the sidewalk a 1/4 mile. The SO brought me a spare battery since I figured the alternator went out and the battery was discharged. With the new battery it was still click click click. I figured it was also discharged so hooked up jumper cables to the car. Still the same thing. Finally getting smart, I hooked up the cables directly to the starter and the thing wouldn't turn over. Went back home and came back with a spare starter - problem gone.

Two magnets had dropped in the Valeo - the two originals that hadn't broken free when I got it a year ago. I'd taken it apart and glued two magnets back into the case - and those two are still holding.

For anyone fixing their own valeo, I found a great source for parts. I got a brand new off-brand copy for $40 shipped on ebay. Except, it's not a guzzi, but for an oilhead BMW. The oil heads have the same magnet housing, solenoid, brushes, brush holder, and planetary gears.

Just the main housing with the magnets was $35 plus $12 shipping from a well known supplier. All of the spare parts I've gotten in a lot of years past have been copies, not original Valeo.

You've got to be careful with magnet housings. They may look identical, but the magnets can be arranged differently which determines rotation direction.

Another thing of note is that the magnets all look the same but aren't interchangeable. There are two distinctly different magnets - a North and a South. The side facing the armature is either a N or a S, and they alternate N, S, N, S inside the housing.

The oilhead bmw and Guzzi starters both rotate the same direction, so their housings are the same and interchange.

[lazlokovacs]

So Roy,

Having a look at the electrical diagram for the lemans,

I need to make a new heavier cable going from battery via a fuse to the starter. What do I do with the old cable that it's replacing? ground it somewhere or?

thanks as usual

[jacksonracingcomau]

to relay not starter
tape up old you made need switched power one day

[Diploman]

This is a Chinese-made "Valeo clone" starter which fits Guzzi's.  For the price, this brand-new starter is probably cheaper than repairing a Bosch or a genuine Valeo "magnet-dropper".  I've had one on my V50 for two riding seasons, and it has been perfect.  Good value for money.  But it still needs to run through a relay wired in the "startup interruptus" configuration for a bigblock, or the "Hayes mod" scheme for an early series smallblock.

https://www.dbelectrical.com/products/moto-guzzi-starter-0307307110-30730710-30730711.html#app-list

[Kiwi_Roy]

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!

Yes it is crazy, that's why Guzzis suffer from Startus Interuptus.
The heavy current only goes through the Ignition switch however, not the start switch that only feeds the Start Relay coil about 100 milliamps.
The Start Relays are typically rated for 100 Amps Inrush so they are up for it, I don't know what the ignition switch is rated for, I can't imagine much more than 10 or 15 Amps

Go back a few posts to my 4 steps of starting reply 26, the high current is only for step 1, pulling in the solenoid.
Time taken at 25 Amps ~ 50 milliseconds or 1.25 Amp Seconds
Time taken at 40 Amps ~ 15 milliseconds or 0.6 Amp Seconds, higher current / less power
(these figures are from my Griso 1100)

I got berated for saying "the V7s are starting to fail" but as far as I can see nothing much has changed.

[Kiwi_Roy]

This is a Chinese-made "Valeo clone" starter which fits Guzzi's.  For the price, this brand-new starter is probably cheaper than repairing a Bosch or a genuine Valeo "magnet-dropper".  I've had one on my V50 for two riding seasons, and it has been perfect.  Good value for money.  But it still needs to run through a relay wired in the "startup interruptus" configuration for a bigblock, or the "Hayes mod" scheme for an early series smallblock.

https://www.dbelectrical.com/products/moto-guzzi-starter-0307307110-30730710-30730711.html#app-list

Yes I think this is a Valeo clone with permanent magnet fields, you can tell by lack of the 4 large Phillips screws that hold the fields in place, I think the new Guzzis are using Chinese starters as well, nothing wrong with that.

Personally I love the old Bosch, they are a manly starter and will run forever if you throw a $10 Brush & Bushing kit in them every 10 or so years.

[lazlokovacs]

going through the lemans 1000 wiring diagram,

there appears to be no starter relay??

is this correct?

[lazlokovacs]

Or....

Are 'starter relay' and 'starter solenoid' interchangeable terms in this thread??

[guzzisteve]

You need a relay, it's $5 at the auto parts store, I would be safe and get one. Horn relay most likely will work. Don't trust the diagram, they can be wrong.

[lazlokovacs]

Ready to put Kiwi Roy's plan into action

But....

I'm getting confused

On the back of the valeo solenoid there are 3 terminals, One which gets the big wire form the battery, another which passes it on to the starter and a single spade connector.

Parts diagram shows quite a strange setup which seems to have a tenuous relationship to reality..?

[guzzisteve]

What is it that is confusing?   Because the diagram calls the relay a solenoid?   Terminal #87 on relay goes to the spade connector on back of solenoid. Terminal # 30 goes to Battery or fuse.

[Kiwi_Roy]

going through the lemans 1000 wiring diagram,

there appears to be no starter relay??

is this correct?

http://www.thisoldtractor.com/guzzi007/schematics/1978_LeMans_II.gif
Yes, this one has the relay miss-labeled solenoid, item (37) is the Starter Relay, it relays the weak signal from the Start button to the stronger signal to the solenoid.

The solenoid is the cylinder on top of the starter motor.
The relay is usually under the seat or somewhere remote from the starter.

[lazlokovacs]

thanks roy

It's all coming together now...

Got some 16 AWG

man that's a chunky cable!!!

[Kiwi_Roy]

Only 50 thou (1.29mm) diameter, the copper that is.

You have my e-mail address do you want to make a simple sketch of what you are going to do so I can check it.

[guzzisteve]

Thank You Roy, even the LM4 supplement calls it the same.

[lazlokovacs]

Roy,

thanks for all your help...

I had a look at the bike today, predictably the wires going to the starter relay didnt actually match the colours in the parts book...

just for the avoidance of all doubt, could you tell me which terminal is which on the moto guzzi wiring diagram?

I'm guessing bottom left is  30, bottom right is 87, but I'm not sure which way round 86 and 85 are.

Hope that makes sense

[wirespokes]

An easy way to tell which is terminal 85 is with a volt meter or a test light. 85 is always hot when the key is on since it comes directly from the fuse block. If you need help, let us know. Test lights are a handy item and don't take much training.

Most of the time the terminals are numbered nearby. So if you pull the relay, turn it over and the numbers should be in plain sight.

According to the diagram 85 and 87 are tied together, so that should make things easy there.

[guzzisteve]

Usually all relays are marked on the bottom or top. You have to rub off the dust and get out the magnifying glass.
But in the diagram you are correct 30 lower left, 87 lower right, 86 upper left, 85 upper right.
30 is brown, 87 is red, 86 is blue with brown going to #30, 85 is black/white
Roy may be busy.
I don't use Carl's diagrams, I use factory.       

[Kiwi_Roy]

One thing to be aware of is upside down on a schematic has no meaning, the designer will draw the terminal anywhere in the box to line up with the wiring.
If you post a picture of the relay we should be able to recognize it.
It doesn't usually matter if you get 85 & 86 mixed up in fact Guzzi mix them up all the time, often between two relays on the same bike, same with 30 and 37 can be mixed as well, it becomes important when you need to use the Normally Closed contact 87a.

[lazlokovacs]

Success!!!

Starter motor spinning like a top!

thanks to all who contributed, Roy, Guzzisteve, wirespokes et al...

help much appreciated

[wirespokes]

 

What got it working?

 

[lazlokovacs]

I did roy's status interruptus fix as outlined above