Modern Vespa

Syd has advised me to post this here instead of General, so here goes.

Hiya chaps, after seeing a couple of threads back in 2018 that were on here involving converting stators to floating earth to be able to use the TrailTech regulator, I would really appreciate some more advice about running an all DC system on my Px200.
If I may indulge you with my story so far - I have an old 80's Spanish PX 200 non-battery/electric starter.
Due to dodgy knees now, I have recently purchased a new set of Pinasco cases, complete with a starter motor and a Flytech flywheel/stator set and also a TrailTech regulator/rectifier as per the threads previously mentioned . . .
Whereas I'm quite happy to do the conversion on the stator to floating earth and totally rewire the scoot where necessary for DC - my problem now is that after reading the TT instructions, they say to "run the negative returns only to the negative of the battery and NOT to earth", which in my simple reasoning means running a positive supply from the TT regulator to all electrical units (lights-indicators-horn) and then the negatives back to the battery, this seems fairly straight forward . . . but . . . I'm at a loss now of how to actually wire the new starter motor, as it would entail running an earth from the battery to the engine/frame, which in my very limited knowledge may eliminate the floating earth bit, but as per usual, I may be totally missing the point . . . I hope that this all makes some kinda sense.
HELP any advice would be greatly appreciated . . . Colin.

"I have an old 80's Spanish PX 200 non-battery/electric starter."

How is it possible to have non-battery with electric starter?

Could be starter-motor harness, without battery?

I ran that for the longest time…

A lot of useless wiring when the starter motor is gone.

There is an oblique (/) in between battery and electric starter indicating that (non) applies to both, sorry that I didn't make it clearer . . .

Lol, you're testing our English literature capabilities…

Waiting for the electric guys to chime in

No you wont be eliminating the earth modifications you have made... what you have described is the way to go. thats where your 12v relay takes over and provides circuit isolation to the affected parts of the 12v circuit...

Here's something i wrote, trying to explain/understand how to do much the same thing with Vape system...


"I'm just putting motor back into Speedy (finally) & need clarity on the BROWN wire coming from motor to coil...

It is currently doing my head in!

It appears to be going to the BODY (as an "earth" or "1 side of the A.C."), however, IF I'm doing D.C. , using a regulator connected to body & 1x yellow wire (which I think is the regulated output wire?) from regulator, THEN it means the BODY is ALREADY 1 side of the A.C. ...
Does this mean ALL of the D.C. wiring needs to be via red & black wires (only) & therefore nil connection on the D.C. side can be to the BODY (as it is already A.C.)?

Is the BROWN wire actually "needed" to make the COIL work, as it appears to be going to the BODY rather than to the coil (due to the rubber grommets)?
OR
Is the brown wire merely to ensure the MOTOR (& ignition/stator) is "earthed"?


The regulator I have is for A.C.

Sooooooo...... & just to confuse everything further ...

Is it possible to;
Leave the BROWN wire as it is...
Isolate the REGULATOR from the body (so its NOT "earthed" to the body)...
Connect the BLACK wire (that comes from the ignition/stator) DIRECTLY to the BODY OF THE REGULATOR...
Connect the BLUE wire (that comes from the ignition/stator) DIRECTLY to one of the YELLOW wires that goes into the regulator...
Then...
Connect the BODY of the regulator & the OTHER YELLOW wire to the A.C. inputs of the BRIDGE RECTIFIER ...
Then...
Connect the D.C. positive to the battery& red wires as required.
AND
Connect the D.C. negative/earth to the BODY (or any black wires as required)?
... this also means...
For items that I want to have as A.C. I can simply run 2 "yellow" wires to them, PLUS the body of the scoot is not negative/earth."

So it's actually a tricky question, mostly as there is AC on motor, which is "earthed" to the chassis via a big wire, therefore basically the chassis is 1 side of an AC circuit, therefore cannot be EARTH for a DC circuit.

and yet when we look at the wireing diagrams for standard Piaggio wireing relative to its postions in the frame... we find it does share the same negative/earth ground

https://scooterhelp.com/electrics/pages/VSX1T.px200.html

@ OP - the wireing diagram you need to search out to do what you are looking to do would be a for any of the 7 wire stators - they were DC from the get go

https://www.scooter-center.com/media/image/54/67/e2/Schaltplan_c16.jpg

scratch all that

follow this guide

https://scooterlab.uk/convert-your-ac-ignition-to-full-dc-for-pennies-workshop/

Thanks GR, sorry more questions, when the starter relay is activated it will temporarily put a positive to the starter motor which will still need an earth/negative from the battery to the engine/frame and will this then bugger anything else up???
Should I put another relay in the engine/frame negative/ground lead?
I've just been looking at other replacement 'full flow DC regulator-rectifiers' using 2 feeds from floating earth stators and their wiring diagrams show that their negative can go to ground and/or neg on the batteries - whereas the TT one states NOT to connect to ground (only to the neg on the battery) - sorry, but I'm confused even more now . . .

Ground is common on AC/DC or full DC systems with an AC stator, no need to separate them. Same thing works on cars, motorcycles, modern scooters, etc. Why would a Vespa be any different...

Just wondering why the TT unit clearly states DO NOT connect to the ground - but after reading the Scooterlab guide it looks like I'm gonna dump the TT unit and buy a cheaper Chinese unit and see how it goes . . . thanks for clarifying a very grey area for me.

Personally, I've done many times the same as in Scooterlab's article and never had a problem with a common ground...

Thanks SaFis, I won't actually be at this stage for a couple of weeks yet, as I still have the new motor in two halves whilst I transfer the inners from the old case - I'll let you know how it all turns out (or not) - watch this space . . . thanks again

I'll start out with saying that Trailtech has been making plug and play full wave DC stator kits for KTM dirtbikes for probably close to 15-20 years (just a guess)? From the factory, all carbureted KTM's (at least from the early 2000's) have a 12 battery and electric start ignitions. The 12 volts that went to the headlight and taillight are 12VAC. The TT kit changes it to full wave 12VDC. With that TT kit installed, any and all of the 12v accessories (stock lights, aux lights, grip heaters, cooling fan, navigation equipment, starter motor, ect) can have their negative wire directly attached to a good ground...whether it's directly to the battery OR the frame. And TT's "universal" regulator/rectifier that we sometimes use on our Vespa DC conversions is the same exact regulator/rectifier that is used on their KTM kits (except for different plug connectors).

So if I understand correctly, you currently have a mid-80's PX?
Your PX was an AC scooter...so no battery and no electric start?
You bought electric start cases and a Pinasco Flytech ignition that has a ring gear on the flywheel?
You now also want a full wave 12VDC ignition system?

If YES is your answer to all of those questions, then I'll proceed a bit more...

Why do you want full wave DC power? If you're just wanting E start on your PX then install a battery and just use the regulator that comes with the Flytech kit.

Oh, and I've converted two different E start 2005 PX150's to full wave 12VDC by floating the ground on the stock stator and using a TT regulator/ rectifier.

WDC, thanks for you input into my problem and I think that you've assumed correctly that after all of the cash that I've laid out so far, all I want is a DC system similar to most modern vehicles, not only Vespas - I'm quite happy to totally rewire the scoot whilst it's already stripped down, so that I have lights that don't go dim and flicker on tick-over and as such the full wave reg/rect units appear to be the way, except that TT one (that I've bought) defo says don't connect the black wire to the ground only to the (-) on the battery . . . Why??
Thanks Colin.

I've done this on a Stella, float the stator and wire he TT into the DC system, done! Nothing complicated here.

Thanks, I'll give it a go and just hope that nothing explodes killing me and the scoot when I push the starter button . . .

Haha, this isn't a three phase power station here! Just a tiny DC system, nothing is going to explode.

Thanks for the re-assurance that I'll still be alive next month . . . Although I do wonder why that TT say not to connect to frame ground?

Hey Colin,
Yes, the TT instructions are correct (so it looks like I gave wrong info). The TT's reg/rec black wire needs to be directly attached to the negative post on the battery. Once that black wire is attached to the battery post, THEN you can run a ground strap wire (or wires) from that same negative battery post to the frame.

And about floating the ground on a 4 pole stator (such as the Flytech)...there isn't much documentation on how to float the ground on those style of stators.

Thanks for that DWC there is very good article somewhere on this forum re floating the ground on the Flytech - thanks again - regards Colin

Hi chaps, just an update as I promised - engine rebuild completed, incorporating new Pinasco starter crankcases, with Pinasco starter flywheel and stator (floated earth done) linked to a Trail Tech regulator/rectifier and 12v battery - swapped all engine components outta the old cases, as they'd only done 3 kilometers since their last rebuild and my knee collapsed - all new wiring done now - threw away the old ignition switch and installed a new one with a sprung loaded starter facility - new 12v DC horn (cut and glued into old shell case), removed the old horn switch (just dremel'd it off) in the light switch and then glued in a new push switch for the horn - drilled the top of the indicator switch to take another push switch for the motor cut-out - I bought a length of a 13 core caravan/trailer wire from Ebay (could have got away with 10 core, but it now leaves spares possibly for later) - changed all bulbs to LED's even the headlight and everything now works from the battery - I changed the indicator unit to one that works with LED's and has an adjustable speed regulator - I also 3D printed the CDi and Stator lead out as they weren't supplied - it fired up first go, at the moment it's running sweetly, with the timing set as Pinasco recommend - it flew through it's MOT test today with everything working as it should . . . . it even bleedin' well starts first kick on the kickstart as well now . . . and you'll never guess what Keaton . . . and yes you guessed right . . it never blew up.
I've attached a copy of my own wiring diagram and a couple of pics taken today - sorry but I'm a touch old school and wanted the GS (fibreglass parts) look for my old 1984 Motovespa P200