What did you do to or for or with your Laverda today?

Paul Marx said:
This is where my charging problem has got me.
I'm now a brother in arms with Hamish.
View attachment 98504
I cleaned up a spare dynamo, put it on the bike and nothing.
I made sure that I was using the right technique to test the dynamo. Either DF to earth and voltmeter on D+ or bridge DF and D+ and from there, voltmeter to earth.
Nothing. The charge light stays on.

So I assume, (sic) that it's the regulator. A bastard of a job to take off. Carbs off and tissue paper down the intakes.
The old and presumably faulty part has been on there since 1990 and seen much use. I do seem to remember opening it up and cleaning the contacts.
A spare regulator is on the bench and will be fitted tomorrow.
Paul

To forget Laverda, I went plodding two hours on the Falcone (which is much in need of some tlc ) this morning.

View attachment 98505
Click to expand...
"I cleaned up a spare dynamo, put it on the bike and nothing."
Hi Paul, I notice you stated that you tested the Dynamo but did you try polarizing it first?
If it has been sitting for a while quite likely it will need this. I had nothing on mine when I got the Eagle and wise heads on here mentioned this.
I tried it, (only needs run for a very short term) and away it went.... Attachment would have been posted by someone else but can't remember who it was to acknowledge:-
 

Attachments

Shajota said:
"I cleaned up a spare dynamo, put it on the bike and nothing."
Hi Paul, I notice you stated that you tested the Dynamo but did you try polarizing it first?
If it has been sitting for a while quite likely it will need this. I had nothing on mine when I got the Eagle and wise heads on here mentioned this.
I tried it, (only needs run for a very short term) and away it went.... Attachment would have been posted by someone else but can't remember who it was to acknowledge:-
Click to expand...
Thanks very much for that.
I've put your diagram in my library.
Today is "change regulator day", we'll see. In fact, the original dynamo was very likely functioning sufficiently on one brush, the other being stuck.

Paul
 
Thoroughly pissed off but getting nearer.
I completely refurbished a dynamo, still no charge on my SF2.
I changed the dynamo, still no charge on my SF2.
I changed the regulator, still no charge on my SF2.
Looking at the wiring diagram, I noticed a red wire running from B+ on the regulator towards the ignition switch, so I followed that up. Nothing.
Hours of work.
1754934924054.jpeg
Then, I remembered that when doing one of the tests for the dynamo, on earthing the DF terminal, the charge light when out when the bike was started.
So, I earthed DF on the dynamo, put a voltmeter on the battery and started the bike. The charge light goes out, and the battery charges.

I'd appreciate some ideas to save me some time..

Paul
 
I may have cornered the problem.
Confirmation tomorrow. I wish that I could be methodical rather than groping in the dark.
I connected DF on the dynamo to DF on the regulator, and the problem would appear to be solved. Loss of continuity in 50 plus year old wiring.
At least I'll sleep well, this has been seriously bugging me.
Paul

I really need to rewire that SF2.
 
Paul,

Your wiring loom seems to be seriously compromised! In stock form, inadvertantly swapping DF and D+ just isn't possible! On both the regulator and dynamo, one terminal has/should have a captive nut/screw and the corresponding wire terminal is cut out to allow connection. I can supply new repro dynamo/regulator pig tails should you require one.

piet
 
The charge light should connect switched power with D+ shouldn't it? A test lamp from the positive terminal of the battery to the D+ on the regulator (or direct to the generator) should go out when the generator produces positive current.
You could try disconnecting everything else and set just the absolute minimum of new wires without the rest of the electrical system and it's old wires (even to the generator), so you are only testing the generator, regulator, and battery. Make sure that the regulator has a good earth. Then it should be easier to find where the problem lies.
 

Attachments

sfcpiet said:
Paul,

Your wiring loom seems to be seriously compromised! In stock form, inadvertantly swapping DF and D+ just isn't possible! On both the regulator and dynamo, one terminal has/should have a captive nut/screw and the corresponding wire terminal is cut out to allow connection. I can supply new repro dynamo/regulator pig tails should you require one.

piet
Click to expand...
I never mentioned swapping D+ and DF, that isn't the case. It's all good.
I think that there's a break in the DF wire which is as it left Breganze in 1973.
Will look into that this afternoon.
Paul
 
Problem fixed.
I repeated what I did last night, a wire between DF dynamo and DF regulator. It worked.
So I checked continuity on the DF wire, it was cut.
So I made up a new loom from the dynamo to the regulator. The DF wire on the old loom was cut where it had rubbed on the back of the crankcase where it goes up towards the regulator.
Just two wires but it involves dropping the dynamo, again, partially dropping the regulator. In all, 5 hours works on a very hot day, grovelling on the floor, my 3C rebuild is on the bike lift.

On the road, I couldn't test continuity, so I did 2000 km with a bike not charging, riding without lights and charging the bike every night.
I obviously made a mess of testing the dynamo and I should have tested for continuity from the moment I got home. Still, I now have a spare refurbished dynamo.

Tomorrow, I'll clean the machine which is as it was after two weeks touring in mixed weather.
Off towards the sea on Friday.

For Hamish, the 530 O ring chain has holes in the inner plates. It's either a DID or an AFAM.

Paul
 
What indication of this issue first appeared on the trip: dead battery, and the bike stopped proceeding. You did fantastically well getting by with emergency fixes. The reason I asked AGAIN is that with a cheap-as-chips dash-mounted volt meter display, not charging immediately gets noticed well before the bike fully stops running, or in my case, explodes a battery from overcharging. Don't you love those deeply buried snapped wires?
 
Vince said:
What indication of this issue first appeared on the trip: dead battery, and the bike stopped proceeding. You did fantastically well getting by with emergency fixes. The reason I asked AGAIN is that with a cheap-as-chips dash-mounted volt meter display, not charging immediately gets noticed well before the bike fully stops running, or in my case, explodes a battery from overcharging. Don't you love those deeply buried snapped wires?
Click to expand...
I couldn't see the charge light on the bike because of my Smartphone case in front of it. I noticed that the battery was flat at our lodgings in the evening. If not running with the lights on, once running, the only drain on the battery is the coils. It'll run all day on the battery. It's a pity that Laverda wanting to seem technically forward looking didn't see fit to fit a kick start. They were so confident in their starting system that they fitted a car battery.
I'm not impressed.
Paul
 
Paul Marx said:
Problem fixed.
I repeated what I did last night, a wire between DF dynamo and DF regulator. It worked.
So I checked continuity on the DF wire, it was cut.
So I made up a new loom from the dynamo to the regulator. The DF wire on the old loom was cut where it had rubbed on the back of the crankcase where it goes up towards the regulator.
Just two wires but it involves dropping the dynamo, again, partially dropping the regulator. In all, 5 hours works on a very hot day, grovelling on the floor, my 3C rebuild is on the bike lift.

On the road, I couldn't test continuity, so I did 2000 km with a bike not charging, riding without lights and charging the bike every night.
I obviously made a mess of testing the dynamo and I should have tested for continuity from the moment I got home. Still, I now have a spare refurbished dynamo.

Tomorrow, I'll clean the machine which is as it was after two weeks touring in mixed weather.
Off towards the sea on Friday.

For Hamish, the 530 O ring chain has holes in the inner plates. It's either a DID or an AFAM.

Paul
Click to expand...
20/20 hind-sight 😁
That dynamo needed a tidy up, I suspect it would have failed shortly anyway, for exactly the reasons you first diagnosed
 
I have replaced those dynamo wires three times over the mere 50 years on my SF. I replace them on any motor I rebuild (not so often these days) as they are invariably really stiff and the sheathing generally cracked here and there and also really hard.
As is often the case, a problem that takes quite a bit of fault finding before getting fixed ends up with quite a bit more on the bike freshened up as a side benefit, and one learns more and more along the way. Good that you finally found the fault Paul.
 
Tippie said:
I have replaced those dynamo wires three times over the mere 50 years on my SF. I replace them on any motor I rebuild (not so often these days) as they are invariably really stiff and the sheathing generally cracked here and there and also really hard.
As is often the case, a problem that takes quite a bit of fault finding before getting fixed ends up with quite a bit more on the bike freshened up as a side benefit, and one learns more and more along the way. Good that you finally found the fault Paul.
Click to expand...
On top of two layers of heat shrink, I passed the wires through a piece of surgical drain tube where they bend up towards the regulator and are liable to chaff against the crankcase.

This problem reminded me of my friend Loic whose 74 SFC stopped firing. It was quite some time before he found that the wires to the points were shorting where they pass inside the crankcase.
Paul
 
Paul Marx said:
This problem reminded me of my friend Loic whose 74 SFC stopped firing. It was quite some time before he found that the wires to the points were shorting where they pass inside the crankcase.
Paul
Click to expand...
Which turned out to be a 1973 SFC works racer with a 1974 SFC spec engine in a SF crankcase.

Marnix
 
You must log in or register to reply here.
Back
Top