Monza 250 - 12 volt with Dyna Booster and points?

Ducati single cylinder motorcycle questions and discussions, all models. Ducati single cylinder motorcycle-related content only! Email subscription available.
Moderator: Morpheus

Moderator: ajleone

folknride
Posts: 9
Joined: Thu Jan 11, 2018 3:08 am

Monza 250 - 12 volt with Dyna Booster and points?

Postby folknride » Thu May 31, 2018 8:40 pm

I’m researching the best - and most cost effective - 12 volt conversion and ignition combination for my 66 Monza 250 project. The Dyna Booster is a “go to” solution for BMW folks. Paired with the 12 volt alternator from Lacey Ducati - does anyone have experience with this combo?
Does it work?
I believe there is also a Dyna III unit (electronic ignition) that works on narrow case singles, but I don’t see it on their site.
I was thinking Electrix + Sachse, but it’s kind of above my pay grade.

Bevel bob
Posts: 773
Joined: Thu Apr 15, 2010 8:01 am
Location: Bromley Kent UK.

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby Bevel bob » Fri Jun 01, 2018 6:55 am

My66 250 has a 12v conversion to the orrig stator(really simple to do) and is fitted with a Pazon cheap booster and points. The box is cable tied to the front downtube under the tank but is just visible enough to see the built in timing light. Easy to time, stronger spark ,small changes to timing in seconds by adjusting points gap. Whats not to like?. I think the Boyer unit is similar

ranton_rambler
Posts: 154
Joined: Sun Jun 04, 2017 11:33 am
Location: Stafford UK

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby ranton_rambler » Fri Jun 01, 2018 9:27 am

I'm planning to use my original generator on my 175, but convert to 12 volt using a solid state reg/rec. Lights will be swapped to LED to reduce demand, and ignition will stay with standard points & coil. The auto advance mechanism all looks good, but we'll see how well it all works when it's on the road.

folknride
Posts: 9
Joined: Thu Jan 11, 2018 3:08 am

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby folknride » Fri Jun 01, 2018 5:43 pm

Bevel bob wrote:My66 250 has a 12v conversion to the orrig stator(really simple to do) and is fitted with a Pazon cheap booster and points. The box is cable tied to the front downtube under the tank but is just visible enough to see the built in timing light. Easy to time, stronger spark ,small changes to timing in seconds by adjusting points gap. Whats not to like?. I think the Boyer unit is similar


Thanks. I’m not familiar with Pazon - I’ll check it out.
I read mixed reviews on using the existing stator to upgrade to 12 volts. I guess it depend on the strength of the magnets, but I have no idea how you check that.

Bevel bob
Posts: 773
Joined: Thu Apr 15, 2010 8:01 am
Location: Bromley Kent UK.

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby Bevel bob » Fri Jun 01, 2018 6:31 pm

It costs nothing to try with the orriginal stator. They do look very basic though . You really need the 60 watt type that was common on the Monza. I think the Monza also had the same advance and retard as the Mach 1 and can be set up to give easy starting yet still have a decent advance range.

ranton_rambler
Posts: 154
Joined: Sun Jun 04, 2017 11:33 am
Location: Stafford UK

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby ranton_rambler » Fri Jun 01, 2018 6:48 pm

That's also my philosophy. If it works - great. If it doesn't - spend a bit of time and money to take it off and fit an Electrex or whatever.
I believe mine is a 60W as it is a slightly later 175 with the "black brick" regulator, but the rectifier part is dead. Stator coils both meter at 0.7 ohm which seems reasonable.
I was once told that a Villiers flywheel with good magnets should take about 50lbs to lift off a steel plate, but not sure if that is also true for Ducatis.

ducwiz
Posts: 271
Joined: Tue May 22, 2012 12:52 pm
Location: near Frankfurt, Germany

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby ducwiz » Fri Jun 01, 2018 8:17 pm

I suppose your Monza has the 60W alternator, with 6 iron yokes arranged in star shape, but only 4 stator coils. You can measure the alternator's power output quite easily:

- disconnect the alternator wires from the regulator (and bury this brick in your trash bin ...)
- if you still have the 6V system i.e. the ground connection of your stator coils: connect two 6 Volt incandescent bulbs, one between each stator wire and ground, with equal power ratings. You start with i.e. 10W bulbs, then 20W (2 * 10W in parallel), finally a 30 W load (3 * in parallel).
- run the engine from your battery! Start the engine and increase slowly to higher revs (up to ~6000/min) while measuring the AC voltage across each bulb, keeping below a maximum of 6.5 to 7 Volts on either branch.
If the voltage is still above 6-6.5 V with a dual 30 W load, your power output equals roughly that value, 2 * 30 = 60 Watt! You can tinker around with bulbs of smaller power rating in the final stage of loading, in order to achieve the maximum power point more precisley, while just keeping the 6.5 - 7 Volts limit.
- if you already have converted to 12V by cutting the stator ground connection, use one or more single 12Volt bulbs across the two alternator wires (avoid ground connection of either wire)

OK, after inserting your rec/reg you might loose a few Watts in the rectifying diodes ...

EDIT: Here https://ducatimonza.wordpress.com/ is an interesting blog dealing with the Sachse ignition and the Electrex 12V alternator for a Monza

cheers Hans

folknride
Posts: 9
Joined: Thu Jan 11, 2018 3:08 am

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby folknride » Sat Jun 02, 2018 12:12 am

Thanks Hans, but the motor hasn’t run in more than thirty years, and is now mostly apart.
I’ve read that blog. Good stuff, but that combination is just too expensive for this project - up around 8 or 9 hundred Canadian by the time it gets here.

ducwiz
Posts: 271
Joined: Tue May 22, 2012 12:52 pm
Location: near Frankfurt, Germany

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby ducwiz » Sat Jun 02, 2018 9:25 am

OK, understood.
So, for me the most economic way to proceed is the 12V conversion by cutting the grounding of the stator coils, and use an electronic R-R like this one: https://www.amazon.com/TC-Motor-Voltage-Regulator-Rectifier-Scooter/dp/B01F4WHW22. The connections are:

- yellow, pink: AC inputs from ungrounded alternator
- red: battery +
- green: battery -/chassis ground
- black: control input/+12V from ignition switch

12V is worthwhile as most of the electronic ignition systems are offer for this voltage only.
You have to exchange the battery, all bulbs, the horn and the ignition coil to 12V types. Fuses must now have half of the former 6V current rating.

You can stay with the points -> zero expense.
If you opt for an electronic ignition amplifier/booster, you should choose one which omits the points, or even better also the automatic advance unit. The Pazon stuff looks good. Here in Germany we have Helotronik: http://www.helotronik.de/, no english wep pages.

This belgian ignition kit https://www.hpi.be/item.php?item=BATK003 is very interesting, but I have no personal experience. OK, it's not the cheapest ...

cheers Hans

folknride
Posts: 9
Joined: Thu Jan 11, 2018 3:08 am

Re: Monza 250 - 12 volt with Dyna Booster and points?

Postby folknride » Sun Jun 03, 2018 1:05 am

If you do the 12 volt conversion using the exiting 60 watt stator, what output wattage do you get?


Return to “Ducati Singles Main Discussions (& How to Join)”

Who is online

Users browsing this forum: No registered users and 15 guests