New guy in Mototrans forum, and merge it all together?

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Singlethump
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Joined: Tue Jun 12, 2012 2:27 pm

Re: New guy in Mototrans forum, and merge it all together?

Postby Singlethump » Mon Jul 02, 2012 12:27 pm

Thanks guys,
It was a hot and miserable ride on the 998 yesterday. We intended to hammer the back roads for about 600 miles but a couple of the guys were getting weak from the oppressive humidity and 93 ish temperature. Ya think they'd listen to this old EMT when I keep hammering them to drink more? No.... So the ride was only about 400.

Gotta apologize a bit here as the owner said it was a 1974. The bill of sale was in the tool kit and it's a 1972. This explains the points ignition vs '73-74 schematics showing electronic ignition. The manufacturing tag/date on the frame has the last digit rubbed off from a cable rub over the years.

Grey is standard, thanks. Sealed beam has some of the ink stamping gone from the number but it is a 40 . . something so I'll at this point assume it's the correct wattage.

As these components are old hat to you but new to me as compared to Japanese parts, I'll flop up a couple pics here. One of the reg/rec devices in the corners, diode? SCR? has a loose stud within it so I'll make the call that it is toasted.

Note the fuse glob. Two fuses and only one is completing a circuit. Accessory?
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Jon Pegler
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Joined: Sun May 16, 2010 6:19 pm

Re: New guy in Mototrans forum, and merge it all together?

Postby Jon Pegler » Mon Jul 02, 2012 3:21 pm

Both fuses are fed from the ignition switch and should be used,if wired in as original.
One is the fuse for the lighting circuit, and goes to the LH handlebar switch via a blue wire.
The other fuse should feed the horn and brake light switch circuit, using a red wire for the horn and a black wire to the brake light switches.

Jon

Singlethump
Posts: 12
Joined: Tue Jun 12, 2012 2:27 pm

Re: New guy in Mototrans forum, and merge it all together?

Postby Singlethump » Mon Jul 02, 2012 4:02 pm

Thanks Jon, I'll look into the second fuse as everything is working apparently off of one fuse.
As to the charging, I'm thinking of something like this. A bit spendy at $150 but I'll keep websearching.
http://www.guzzino.com/6vsiphrere.html

Singlethump
Posts: 12
Joined: Tue Jun 12, 2012 2:27 pm

Re: New guy in Mototrans forum, and merge it all together?

Postby Singlethump » Mon Jul 02, 2012 7:08 pm

Well looky what I found on the web!
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DewCatTea-Bob
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Location: Near SE side of Lake Michigan

Re: New guy in Mototrans forum, and merge it all together?

Postby DewCatTea-Bob » Mon Jul 02, 2012 11:42 pm

Singlethump wrote:Well looky what I found on the web!
____ That diagram appears to be that which you must have, (for 1972 250-Mototrans).
__ I don't know of any 350-Mototrans models which used (the depicted) ign.points, however.


" One of the reg/rec devices in the corners, diode? SCR? has a loose stud within it so I'll make the call that it is toasted. "

____ Fair-call, as it stands-to-reason that that SCR has developed an open-circuit.
__ You could disconnect the associated yellow alt.wire-lead and instead connect it to a power-diode,, as the regulator-circuit in the r/r.unit should still be able to continue controlling system-voltage (so long as the battery also remains connected-up of-course).
Otherwise, it seems you'll have to spend about 20-bucks on a replacement r/r.unit.


Duke-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob


DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

Re: New guy in Mototrans forum, and merge it all together?

Postby DewCatTea-Bob » Tue Jul 03, 2012 9:30 pm

" I'm regulator shopping.
Any suggestions welcome. "

____ Other than a stock Ducati unit, I don't know of any others made to work with Ducati's unique 'dual half-wave' rectification process, as most other r/r.units are made for ordinary full-wave rectification charging-systems.
__ Besides, even-though one of your stock-unit's two DC.valves has developed an open-circuit, that doesn't mean that it's regulator-circuit can no longer function ! _ As it should still be able to control at least half of the alternator's total-output, and it's only THAT extra output which ought possibly need to be regulated, cuz as you have already learned, the available power-output from only one (of the two yellow power-output circuits) is INSUFFICIENT to keep the battery charged (with lights on).
So the cheapest/easiest way-to-go is to connect the unused yellow-alt.wire's output (that's been connected to the bad SCR), to a power-diode instead, so that THAT circuit is always putting-out full-power to the load-system.
And with the remaining yellow-alt.output still left connected to the working-SCR, the r/r.unit can then still regulate the power-output from that other half of the alternator, (if & when your high-speed riding calls for any power-output cut-back).
____ If you don't understand that reasoning, then you can do what most others have done, and install the wrong type of rectifier -(full-wave). _ And those type of units can be found (with built-in regulator) for under 30-bucks. _ So there's no need to consider paying for such with jacked-up retail-prices !


Hopeful-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob

Singlethump
Posts: 12
Joined: Tue Jun 12, 2012 2:27 pm

Re: New guy in Mototrans forum, and merge it all together?

Postby Singlethump » Thu Jul 05, 2012 6:13 pm

Thanks Bob.
I disconnected the bad scr and ran it. Jumpered per your data, then disconnected the 'good' scr. Lights off for no system load and still no charging. Just for grins I disconnected the OE reg and patched in a full wave bridge I had. As expected the DC climbed over 8V as it's unregulated.

I haven't talked to the owner as he's knee deep in business but we'll likely buy something off the shelf. Depending on the unit I can run both yellows for full wave, earth the red for half wave, or leave the red center tap open. I don't know what the aftermarket units use for regulation whether it's a scr chopper or simply zener(s). That's not critical, so it's just a matter of who has what for a 6 V system. Hmmm, unless we change all the bulbs to 12 V then use a 12 V reg. I'd imagine the coil won't care. On second thought, nix the 12 V as the guy just bought the new 6V battery.

DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

Re: New guy in Mototrans forum, and merge it all together?

Postby DewCatTea-Bob » Thu Jul 05, 2012 8:06 pm

" I disconnected the bad scr and ran it. "

____That ought to have made no difference, as it was expected that that SCR was already an open-circuit anyhow. _ (While the good SCR would still try to keep the system charged by itself.)



" Jumpered per your data, "

____ Don't know what you mean, as I had recommended substituting an independent power-diode/DC.valve for the yellow-circuit which had been connected to the bad SCR/DC.valve.



" then disconnected the 'good' scr. Lights off for no system load and still no charging. "

____ If a power-diode had been properly substituted in place of the bad SCR, then with that charging-circuit by-itself and with the lights turned-off, (thus merely just the ign.load),, then 'charging' should begin by 4-grand/RPM, and possible over-charging beyond 6-grand.
If the substitution was actually done and there was "still no charging", I'd then suspect that the yellow alt.wire-lead circuit had an open-circuit somewhere (probably only during the test), cuz I expect that you would've had the polarity of the power-diode connected properly.



" Depending on the unit I can run both yellows for full wave, "

____ It may be found that only one yellow and the red will be sufficient for normal-type riding.



" earth the red for half wave "

____ Doing that could lead to a short-circuit (with a normal neg.ground system).



" or leave the red center tap open. "

____ While it APPEARS that the red-wire is a 'center-tap', it's actually a 'common',, as in this case it's not a REAL center-tap, but rather a common-line which carries both opposite-polarities of the two yellow wire-leads (connected to the two SEPARATE [non-continuous!] alt.stator-windings).



" unless we change all the bulbs to 12 V then use a 12 V reg. I'd imagine the coil won't care. "

____ The 6-volt ign.coil could remain, although I'd recommend a ballast-resistor be connected in series with it.


Dukaddy-DUKEs,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob


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