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Mine is an Electric Start Strada - starter works fine.

The issue I have is with charging, if I put a multimeter accross the battery terminals with the battery in place and rev to 2,500 / 3,500 or therabouts, the measured voltage varies hugely between about 9 volts and something like 19 volts.

It will hold around 14 volts (which is probably about right?) for a few seconds and then swing wildly again.

I have checked all the connections that I can and they all look sound, as do the fuses.

The alternator coils all look in good shape - no signs of discoluration, and all soldered connections appear in good order.

I can see that one of the coils has been re wound (the transducer one?) this confirms what the vendor of the bike told me.

Battery is capable of holding charge and turning the starter so my suspicions fall on the regulator.

The regulator box has a silver cover held on it held in place with 4 screws so I assume it is perhaps the OE one the cover has lots of italian writing on it !

It looks like Mdina have some used regulators in stock, so perhaps I need to consider replacing the regulator, or perhaps repairing the existing one - I have a background in electronics so have a reasonable understanding of components, if there is a circuit diagram around I could probably test it at component level.

What is the general concensus ?

I would agree the rec/reg is the likely culprit here. I'd go for a modern replacement unit and am sure Mdina will have something suitable. Look for something rated for 150 Watt upwards for a bike with a starter motor-I can get away with a lower rated item as I have the older lower output alternator.
On the other hand, if you are confident at repairing these things you could even build a new replacement too!

Thanks Steve

I will double check the wiring just to be sure found this: https://morini-riders-club.com/Nederlan ... gelaar.gif looks to be a trusted source so might pop the top off the regulator box after I have double checked the wiring and see how it compares.

Been busy making a flywheel holding tool this evening - I knew I would find a use for an old MZ clutch perssure plate that I had - turned down the O/D and fitted 3 studs @ 120 degrees, just need to fit the handle to it tomorrow.

It's all good fun.

Hi,
Also be aware of the connections in the fuse panel - well documented about the need to check 'rivet' tightness on the terminals in the fuse box. Type "fusebox" in the search function for more info.
If loose, they can cause the very issue you are experiencing.
Much cheaper to fix than another regulator, and should really be checked/eliminated from doubt before you go any further.
Regards, George

Thanks for that George, I will make sure I take a close look at it.

Yes, exactly what George said. Those fuses can cause a myriad of issues!

Andy_C wrote: ↑23 Sep 2024 20:20 Been busy making a flywheel holding tool this evening - I knew I would find a use for an old MZ clutch perssure plate that I had - turned down the O/D and fitted 3 studs @ 120 degrees, just need to fit the handle to it tomorrow.

Be cautious with the length you make the prongs. Many a set of stator windings has been wrecked by the prongs being long and coming into contact with the windings. Just saying

Good call Bumblebee - did not even cross my mind.

Good news is that I have used M6 Socket Cap Heads for the pegs with the heads turned down to fit the holes in the flywheel, they only protrude a couple of mm behind the electric starter rim or whatever that part is called !!

Open to any advice as I am total Newby to Morinis.

George 350 wrote: ↑23 Sep 2024 20:29 Hi,
Also be aware of the connections in the fuse panel - well documented about the need to check 'rivet' tightness on the terminals in the fuse box. Type "fusebox" in the search function for more info.
If loose, they can cause the very issue you are experiencing.
Much cheaper to fix than another regulator, and should really be checked/eliminated from doubt before you go any further.
Regards, George

Yes-I should have thought of that as well. Probably didn't since I haven't had one of those fuse/connector boards for years now! Ditch it years ago and now have a mess of cables and connectors under the sidepanel instead. No-one will ever know!

I took a look at the fuseboard / connector board in mine this evening.

The rivet that holds the faston terminals for the leftmost fuse at the top have given up, all of the others appear to be OK.

The main fuse holder is some kind of horrible in line thing that you twist apart to get at the fuse.

The previous owner looks to have made a good job of a "star" earth point on one of the regulator mounting points.

I have a colour print of the wiring and it tallies with the fuse / connector board so it should not be to difficult to replace with some decent modern blade fuses and some durite or similar terminal blocks.

Seems the concensus is to replace it so I think that will be my plan of action - have the whole winter to do it as I only plan to use the bike during the Spring and summer months.

I will take lots of pictures / notes of the rats nest before I do anything as it looks a bit daunting but from the diagram looks pretty straightforward.

Hello. I think you will find a circuit for the regulator in the library, or the Dutch sigte archive, or Paul Compton’s site.
I have used a modern reg on a couple of Morinis, Very simple to install, just isolate the red lead from the stator. They were ’Powerbox’ from a well known company whose name escapes me for the moment. They were non electric start bikes though.

Andy_C wrote: ↑24 Sep 2024 21:32 I took a look at the fuseboard / connector board in mine this evening.

The rivet that holds the faston terminals for the leftmost fuse at the top have given up, all of the others appear to be OK.

The main fuse holder is some kind of horrible in line thing that you twist apart to get at the fuse.

The previous owner looks to have made a good job of a "star" earth point on one of the regulator mounting points.

I have a colour print of the wiring and it tallies with the fuse / connector board so it should not be to difficult to replace with some decent modern blade fuses and some durite or similar terminal blocks.

Seems the concensus is to replace it so I think that will be my plan of action - have the whole winter to do it as I only plan to use the bike during the Spring and summer months.

I will take lots of pictures / notes of the rats nest before I do anything as it looks a bit daunting but from the diagram looks pretty straightforward.

I wouldn't say there is any concensus in the club about replacing the fuse board, after all they have worked for around 50 years. Yes after decades the odd rivet might get loose but you can tap them tight again, and if you have a lathe you can make new rivets I have done so myself. Also the mass of wires isn't untidy if its routed as originally done in the factory. In jap bikes of the period it was in the headlight which I would say was even worse and made really chunky looms at the headstock. I have seen some people's attempts at changing the the fuse board and they are not always better or neater or reliable. Sometimes its better to overhaul the original fuse board if you have the skills and tools, then it will go for another 50 years. Also beware any suggestions of soldering up the rivets as the plastic of the fuse board melts easily and then all the terminals go loose.
The star earth point on the regulator is normal practice, might even have been standard.

I have replaced more than one of thiese rivets with a small screw and nut

Hmm, got me thinking now.

Apart from the one rivet as I said everything looks pretty good - none of the other rivets appears loose.

The 3 fuses are also held in pretty tightly, so perhaps just best to fix the loose rivet, and bin off the existing main fuse that is in the battery lead - that thing really is horrible.

Can anyone tell me what circuits the 3 fuses protect reading left to right and the fuse ratings? - not been able to find that out yet.

Thanks.

Andy_C wrote: ↑25 Sep 2024 20:30
Can anyone tell me what circuits the 3 fuses protect reading left to right and the fuse ratings? - not been able to find that out yet.

Thanks.

This is how my standard 31/2 is;

The fuse on the Left protects GREY which is the headlight (55/60Watt on mine) and I would suggest a 16A fuse.

The fuse in the Middle protects VIOLET which is indicators, stop light, horn, flash headlight and I would suggest a 25A fuse.

The fuse on the Right protects YELLOW/GREEN which is the rear light, lights in the speedo/tacho and I would suggest a 6A fuse. Although I have a sixteen in mine so if my headlight fuse blows I can swap it and have a chance at getting home in the dark.

Remember the little ceramic fuses rating marked on them is the continuous current they will withstand. Faults like a short circuit will blow them, but are short duration and under those conditions the fuses blow at about 2x that current.

To be honest as others will probably say, the whole bike is wired in the same size wire and protecting it with fuses probably there is some scope for artistic licence in the selection of fuse sizes.
Too big and you don't protect your wiring so well.
Too small and things like transient switch on/off currents will blow your fuses.