RT Rebuild and questions

[Eldert]

Hi Graeme

i did use the 2 yellow wires to convert to 12 volts

Eldert

[DewCatTea-Bob]

By: graeme...
" Regulator question please, "

____ Not sure that you should've used this particular thread for this non-R/T inquiry.



" I'm using a scrambler alternator and flywheel and the regulator I have is a 4 wire reg, 2 yellows, red positive and a negative "

____ I gather that you likely have all stock wide-case type charging-system parts !?
__ If so, the rect.box has two yellow-alt.inputs, two red junction-terminals, and a brown battery-power sensor-terminal.
There is NO "negative" terminal ! - (That metal rect.box is grounded.)



" (I think, as it's at a mates place for him to test that it works) "

____ If he's not VERY familiar with the stock rect.box operation, then he'll likely conclude that it doesn't work (as normally expected by others).



" The alternator has 2 yellows and a red center tap wire. "

____ The red-wire is not actually a real 'center-tap',, rather, it's a 'common' -(it supplies the opposite polarities of BOTH of the two separate yellow-leaded alt.windings).
(Others may tell you otherwise [than myself], but then THEY are the ones who are not really correct !)



" Can I just blank off the red wire and use just the 2 yellows? "

____ No, not if you're planing to continue using the stock-alternator along with it's stock-rect.box ! _ That rect.box is not a F-W.rectifier, and-so the red-wire is needed (to supply the two separate half-wave outputs). _ So without the red alt.wire-lead remaining connected, there can then be no charging-output supplied.


____ More questions ?



Duke-Cheers,
-Bob

[graeme]

Hello Eldert, thanks.
Hello Bob,
The 12v regulator is from a Ducati, but I don't remember which model, perhaps an 860?
I'll get the reg back from my mate and supply the correct information from it to you.

To be clearer of what I'm doing,
450 Scrambler alternator and flywheel
12v battery
12v regulator as mentioned
Head light H4 bulb you suggested earlier, very little night riding.

The reg tests ok

Graeme

[graeme]

Bob, the regulator is Ducati, 344262, 12v 18amp.

The terminals are
G G R B+ L C

R and L do not have terminals

B is battery positive and C is ignition switch as I believe?
And the two yellows go to the two G's

Graeme

[DewCatTea-Bob]

" The 12v regulator is from a Ducati, but I don't remember which model, perhaps an 860? "

____ If from either a 750 or (early)- 860 L-twin, it ought to work well enough for your expected 12v.system.



" Head light H4 bulb you suggested earlier, "

____ Concerning a H4 type 12v.bulb, I only recall recommending Sylvania's 65/45w (bulb made specifically for motorcycles). _ THAT H4-bulb should work fine with such a stock-type Ducati charging-system.



" The reg tests ok "

____ I take-it then that your tester/friend already knew of the proper way to test a Ducati rectifier-unit.



Stay-Tuned,
-Bob

[DewCatTea-Bob]

" the regulator is Ducati, 344262, 12v 18amp. "

____ I don't know if "344262" is of any distinguishing help. _ If from a later model of 860, then it would not be made to work correctly (as intended) with the older type Ducati-alternators.



" The terminals are
G G R B+ L C
R and L do not have terminals "

____ I'm not understanding that clearly. _ Is each & everyone of those 6 letters labeled on your r.unit-box, for just 4 connections,, or what ? _ (I'm not real familiar with the later-type 860-r.box/unit.)



" B is battery positive and C is ignition switch as I believe? "

____ That seems correct, as battery-power supplied from the key-switch is required to turn-on the rect.box's internal-circuity.



" And the two yellows go to the two G's "

____ Correct, (as "G" stands for 'yellow' !).
____ Do you have any pix of your rect.box ? _ I believe the later-type 860-r.box/unit, (unlike the older-type units), is finned.



Duke-Cheers,
-Bob

[graeme]

Bob, here's a picture of a reg from a '76SS I got from the internet.
I haven't had time to pick my reg up as yet.



The one I have is the same.

There are no terminals for R and L. They are blanked off.
I would think that the black plastic piece was used for all regs and only the terminals needed were fitted?
Regards
Graeme

[DewCatTea-Bob]

" here's a picture of a reg from a '76SS I got from the internet.
The one I have is the same. "

____ Well as I had become concerned with, your Ducati L-twin r.unit is the newer-type (that's made to work with a newer-type alternator which is intended to be FULL-wave rectified), and is not meant to be matched-up with the older-type alternators (of which their stators are specifically wound to be dual half-wave rectified).
__ Now that I see a picture of such, I can understand what you had meant about two of the terminal-points not having actual terminals,,
and I also now realize why your tester/friend had no problem checking-out your r.unit, as it's the less-complicated/more-standard simpler type (for getting checked-out).


" I would think that the black plastic piece was used for all regs and only the terminals needed were fitted? "

____ That's as good a guess as any, I guess...
I-myself don't have any experience with those newer/finned-type L-twin r.units,, and-so would shy-away from experimenting with them, due to their replacement-cost.
__ I now gather that you've been advised by somebody who HAS tried using one of these newer-type r.units with our older-type alternators. _ Cuz with such a match-up, ya would then indeed connect-up just the two yellow alt.wire-leads only, and ignore the red alt.wire-lead.
In such case, the alternator would provide sufficient charging-power, however it would be doing so out of (originally-intended) concert.
This simple connection-circuit is not something I-myself would do, but it ought to work well enough for you.
__ I had advised to another, (who was intending to use a FW.rectifier with his Duke-single), to first try connecting-up the red alt.wire-lead and just one of the yellow alt.wire-leads, so as to learn if the resulting/expected lower power-output would still possibly be sufficient for his particular needs, (as there ought be little real need to produce more than is really required, and thus may make life easier on the alternator as well).


Hopeful-Cheers,
-Bob

[graeme]

Hello,

What holds the RT tank in place apart from the 2 x rubber mounts in the middle of the tank?
What stops it from rocking forward or back?
I would think there should be a rubber pad at the rear between the frame and tank, and maybe another one wedged between the frame and the tank at the front?

Am I missing something?

Regards
Graeme

I found out there are 2 curved rubber pieces, front and rear of the tank that sit over the spine tube.
70 x 130 x 20 thick

[graeme]

Getting closer,,,,,
Shock springs, wiring and ignition still to go.