Moto Guzzi Le Mans Mk 1 1978 850cc

[Bixxer Bob]

From the front it's a yellow stripped for maintenance 748, behind it an orange Laverda 750S, behind that a black Gilera 350, then to the right there's the blue Guzzi, behind that a yellow Ducati 900SS then the one you're interested in, a red and black Morini 3 1/2 then next right the Stark and finally in front of that the Gas Gas.

Here's a better pic of the Guzzi for DeepSouthTiger, it's been resprayed Ford Midnight Blue:

[Bixxer Bob]

Checks today revealed that 12v across the sliprings produces magnetism in the rotor, but - with the ign on - no 12v is coming out of the slipring supply from the reg/rec.  Next step is to run the engine with 12v direct from the battery to the slipring brushes to see if it charges.  If it does, result, I'll just put in a wire from the ign switch.  If it doesn't, but still with the 12v in place, I'll check for ac coming from the stator.  I'mnot sure what the voltage should be but as long as they're all the same I'll then be happy the fault lies with the reg/rec.

Edit: just read a document sent to me by NeilD. It seems that some bikes weren't fitted with a ballast resistor so if the ign warning light bulb fails, the charging circuit stops working, which seems a bit unfair; as the one thing that could tell you the battery is going flat, is the cause of the battery going flat!

[Sin_Tiger]

  doesn't quite do that piece of Italian electrical design justice, must have gone to the Lucasi school of electrical engineering 

I listed after a 3 1/2 Moroni when I was at school, then I followed one round a few corners on my Tiger Cub and went off the idea quickly, nice looking bike just the same.

[Bixxer Bob]

Agreed the Morini is a pretty bike. This is the second one I've come across, the other was one stored in the bike club at RAF Wyton for many years.

As for the electrics, it's hard enough not having a manual, but adding in previous owners modifications is making it even more fun.  Not.  I'm learning a lot though 

Like with Girly knowledge, you have to sift through an awful lot of other people's supposition (read: bollocks) to find the gems of good info and come to some sort of meaningful understanding.  I stop short of using the term "knowing" because - taking as an example the Sagem ECU - a lot is best guess; it's not possible to find out exactly what's going on beacuse the code is locked.  At least with these older bikes they have fairly simple systems so it's just a case of working out how the dots join up.

One reason I air my theories as they develop/share my pain on here is so that others can help with said development/develop their knowledge at the same time

[cosmo]

You hit on why I don't own Italian bikes anymore. Lucas, Miller, Wipac I get. Ducati Elettrotecnica and Magneti Marelli made me lose ALL my hair.

I once changed an Aermacchi to a Honda charging system, the OEM was so bad. Yes, it took some machining, but worth it.

I changed a Ducati 860 to a Dyna III ignition. More machining. Result: both ran. More than you could say for stock. Also changed the regulator to Zener diode, the controls to Honda, etc. etc. etc.

Though, truly, Moto Guzzi electrics were the best of the (bad) lot. And I LIKED the switches, nice and compact. Just poorly made.

Italian bikes were so traumatic, I'd almost welcome a French motorcycle...but I've owned Citroëns.

Cosmo

[metalguru]

...but I've owned Citroëns.

What a brave man.

[Sin_Tiger]

...but I've owned Citroëns.

What a brave man.

Citroën parts dept. (GS X2)  "I need all the bits to replace the exhaust system" 30 mins later a huge pile of parts and a similar long bill "I only need the exhaust parts, not the engine and transmission rebuild kits"    you'll need those for putting it all back together after you replace the exhaust"

Gun gum, Heinz beans can, house clips, Autotrader, sorted

[Bixxer Bob]

I remember helping a friend do the exhaust in his Citroen (think it was a CS?) in 1981. As well as having to remove all sorts of ancilliaries we had to unbolt the engine and jack it up to get the old pipework out.

And I realised when sorting an ign problem on another friend's 2CV that Citroen took a set of points and built a car around them. Front if the car had to come off to get at them.  Then there was the Renalt 5 oil filter that was accessed through a hatch in the wheel arch. 

When you think about it, bikes aren't so bad....

[metalguru]

About 35yrs ago I vowed never, ever, ever work on any French car of any description what so ever, only exception was to totally remove it from the face of this earth.

Caused a lot of arguements and fed up customers but stood my ground every time. To say the least it was an experience gained decision.

A good party trick was to cut one in half just behind the drivers seat as the things are front wheel drive and hurtle round a field untill something in the engine made a bid for freedom or it caught fire etc......AAAHHH happy days.

[Timbox2]

...but I've owned Citroëns.

Cosmo

And I used to work on them, DS's to be exact, fantastic cars, 20 years ahead of their time, but yeah, challenging to say the least, most days we would end up making ourselves another special tool to do something or the other, I can remember adjusting the handbrake required a 2ft long bar with a 10mm Open end spanner welded to the end.(Inboard Discs). Made some money though, as you say nobody would touch em, including most dealers

[John Stenhouse]

Citroens, just what you get used to.

At least with most Citroens you get good brakes that don't seize and you don't have to change the fluid every two years because it's got water in it.

Most of the other stuff is just experience, like the points for instance, anyone like to explain where else you would put them on a flat twin? Only two answers front or back......

[Bixxer Bob]

OK back on track.  The Guzzi charge warning light lamp had failed, but replacing it didn't do anything for the lack of volts at the slipring.  I now need to study the reg/rec diagram and see what it's doing.  Could be that it's not passing the 12v supply through because it doesn't sense the battery needs it - going on the theory that the reg/rec varies the slipring voltage to control the stator output.  Can't wait for next week's exciting installment

This is turning into a much bigger learning experience than I thought.

[metalguru]

The wattage of the warning lamp is crucial to the effective charging, the exact wattage of the lamp escapes me but just saying.

[Mustang]

 

[Bixxer Bob]

The wattage of the warning lamp is crucial to the effective charging, the exact wattage of the lamp escapes me but just saying.

Aye, I got that from NeilDs pdf.  Since all lamps are the same, I'm taking a punt that I have the right one.  I assumed (wrongly) that with ign on and engine off I'd get 12v at the slipring connection coming out of tye reg/rec. Not true.  So far I have12v to the lamp which lights when grounded.  Next is to re-assemble the whole thing, start her up, then fault find.