1971/72 125 Scrambler "Renata" (Rebirth)

[J-Man]

So after a little investigation so as to figure out what alternator my bike has, so that I can plan a course forward in converting the 6v system into 12v, my Rectifier/Regulator is stamped "6v 12A max." And "34.41.06" which I think is the part number, it's much weaker than I expected, but seeing as all it had for draw was a few lights, I guess it makes sense.
Conversion means changing the Rectifier/Regulator, the battery(don't have one yet), all the bulbs(was thinking of going all LED to lower current draw), maybe the horn(seen a few posts stating it may be fine as-is), and the coil.



My other option, is to use a DC to DC step-up converter like this: http://www.ebay.ca/itm/Industry-Grade-D ... 1182096801
Since the main reason I want 12v is to run the LED blinkers I bought, they are 12v 7W, I'm thinking this may be the most economical option, especially since I don't really want to crack open the cases(to investigate the alt.) till winter, because I'm planing to open it up then make sure all is well, there are so many questions about which gaskets, seals, and bearings are required, it could be 3 months till everything is sorted out, which would mean no riding it this year.

I'm interested in hearing others thoughts on these options.

[ducwiz]

Hi,

I made a 12V conversion for this regulator many years ago, see on http://ducwiz.minus.com/m1pfYbm8J.
You also have to change the horn, which in 6V version draws twice the current from a 12V battery, and will not survive this excess power.

I don't know which alternator is hidden inside. The regulator is the same as on the wide-case 250-450 models. Their alternator delivers 90 Watts (points ignition), or 75W if it is the CDI version. So, the idea of using an 18Watt DC-DC converter is definitely not applicable.

Btw, engine and carb have been made in Spain, by Mototrans. Afaik, the engine is more or less similar to the older italian 125 Sport and TS models.

Around 1976, I picked up two young italians on a 125SCR, on their way from Bologna to Amsterdam! The piston had a hole burned in his crown, which we got welded in a local machine shop. Afair, during road tests after re-assembly, I noticed a 5-speed gearbox. Can you confirm this for your bike?

A workshop manual for the small engines (italian language) can be downloaded here: http://s5.histats.com/stats/r.php?104172&100&58&urlr=&www.rpw.it/Files/Ducati_Motoleggere_Monoalbero_ManOff.pdf.
Infos (spanish) about Mototrans bikes can be found on http://perso.wanadoo.es/kombo/index.htm
Very interesting: These bikes may have been sold with 160cc engines (Monza Junior?) http://www.topspeed.com/motorcycles/motorcycle-reviews/ducati/1970-ducati-125-scrambler-ar129395.html

Finally: This one is for sale in Berlin/Germany: http://www.ebay-kleinanzeigen.de/s-anzeige/ducati-scrambler-125-tuev-neu/341312181-305-3436

Hans

[J-Man]

Hi,

I made a 12V conversion for this regulator many years ago, see on http://ducwiz.minus.com/m1pfYbm8J.
You also have to change the horn, which in 6V version draws twice the current from a 12V battery, and will not survive this excess power.

Thanks for the reply.
Good to know it should be replaced if I do a full 12v conversion.

I don't know which alternator is hidden inside. The regulator is the same as on the wide-case 250-450 models. Their alternator delivers 90 Watts (points ignition), or 75W if it is the CDI version. So, the idea of using an 18Watt DC-DC converter is definitely not applicable.

I wasn't planning to use the small DC to DC converter to run everything, just the critical components that I can only run on 12v, which would be the signal light system.
Hopefully it does use the same alternator, it will make it easier to find a replacement if it ever dies.

Btw, engine and carb have been made in Spain, by Mototrans. Afaik, the engine is more or less similar to the older italian 125 Sport and TS models.

I've heard it's based off the 160, also heard it's based off the 125... I honestly don't know what to believe, there is so little documentation out there it could be anything.
Finding the correct shop manual would be the Holy Grail for this bike, as it would answer all questions, I would assume there is a Spanish version, possibly an Italian version, both of which won't help me as much since I don't know those languages, but translating would be better than nothing, I would assume there is an English version out there as I would expect the the seller/importer to be able to service them, my searches have turned up nothing....

Around 1976, I picked up two young italians on a 125SCR, on their way from Bologna to Amsterdam!

Girls or bikes?

The piston had a hole burned in his crown, which we got welded in a local machine shop. Afair, during road tests after re-assembly, I noticed a 5-speed gearbox. Can you confirm this for your bike?

I didn't get the chance to ride it, only have it run before dismantling the bike, but everything I've read says it's a 5 speed, I'll try and confirm it today somehow.

A workshop manual for the small engines (italian language) can be downloaded here: http://s5.histats.com/stats/r.php?104172&100&58&urlr=&www.rpw.it/Files/Ducati_Motoleggere_Monoalbero_ManOff.pdf.
Infos (spanish) about Mototrans bikes can be found on http://perso.wanadoo.es/kombo/index.htm
Very interesting: These bikes may have been sold with 160cc engines (Monza Junior?) http://www.topspeed.com/motorcycles/motorcycle-reviews/ducati/1970-ducati-125-scrambler-ar129395.html

Finally: This one is for sale in Berlin/Germany: http://www.ebay-kleinanzeigen.de/s-anzeige/ducati-scrambler-125-tuev-neu/341312181-305-3436

Hans

Thanks for the links, they have helped.
I was told that my bike was a 160 when I was buying it, but there is nothing on the bike that supports that claim, both frame and motor serial # stamps say 125, as does the cam cover.

[J-Man]

I may as well post an update...
The seat is getting recovered, I had to deal with some heavy rusting of the seat pan, thankfully it didn't eat through, the rust is now gone, and is now painted, I also have the new vinyl.

The shocks and forks have been sent to a RaceTech service center for a rebuild, the shocks had zero compression resistance.
They should be awesome when they get back.

I've been busy polishing bits and pieces, the fork lowers, and shocks before I sent them out, both front and rear brake covers, the front hub has a preliminary polishing(to see how bad the scratches are) as both hubs need to be soda blasted(or more aggressive) to remove rust and staining, I straightened the seat trim and polished them, of the 6 rusty bolts that hold them on, only 1 didn't destroy its self when taking them off the seat(replacements are on their way), the motor will be soda blasted soon, the levers look beautiful, I removed all the leftover casting marks prior to buffing.

I have a box of parts to get chromed, a few to get nickel, and I think I will get the brake and clutch adjuster wheels black chromed, I can get nice replacements if I need to.
The biggest job left to do is the swing arm bushings, I've been procrastinating this part, as I really wanted to go with needle bearings, oh well, I have to move forward, as I can't paint the frame till its done, so this week I'll be talking to the bushing guy(there, it's in writing).

The gas tank needs some dents & paint removed, then paint.

I'm still looking for fenders, the 450RT fenders don't look right, I'm not to worried about the front right now since I will probably be doing something custom as I don't really want the off-road look, but I would like to have them to paint along with the tank and side covers for color matching.

[J-Man]

Anyone have center stand measurements? There is a small tube through the rear motor mount that looks like it could be used for that purpose, my side stand is from a different bike, the angles are wrong and the mounting tab was bent, so I'm looking for the correct one, but I'd prefer a center stand.
Thanks in advance.

Edit: some measurements:
I.D. Of tube = 10.2mm
Length = 110mm
And is located about 8cm back from the lower rear motor mount bolt.

[J-Man]

The blinker wiring has just been test wired and it works great, Motogadget M-Wave to do the flashing, M-Blaze Disc for the blinkers, momentary switches to start the flashing, micro controller to preset the self cancelling delay(set to 10 seconds), and a relay for holding contacts, everything fits within the handlebars, only 2-3 wires will exit the bars, likely as a cable which will blend in with the clutch, brake, and throttle cables.
http://www.ebay.com/itm/Timer-5v-12v-24 ... 1875747850
http://www.ebay.com/itm/10x-Mini-Electr ... 1574354545