Modern Vespa

Doesn't look as bad as I expected it would be.

No it really wasn't once I figured out the order of tupperware removal.

I am intending to paint my tupperware at some stage so any little helps...

I just picked up a spare Piaggio branded MP3 voltage regulator on eBay for $35. There is 1 more available if anyone is interested.

http://cgi.ebay.com/ebaymotors/Piaggio-MP3-250-400-500-Voltage-Regulator-_W0QQcmdZViewItemQQitemZ200507368974QQptZMotorcyclesQ5fPartsQ5fAccessories#ht_500wt_1171

I saw those but they did not look like the voltage regulator that I took out so I sent him this message on ebay.

Dear motoretta_cdn,

Hi, does this replace Piaggio part no. 58086R-37? I
only ask because it
looks nothing like the oem
voltage regulator and I don't see cables
attached to
it. Thanks.

This was his response:

Dear stickyfrog,

The voltage regulator doesn't come with cables. The
part number you are referring to is for the Vespa
GTS and this one is for the Piaggio MP3 250/400/500.
Thank you for your interest.

- motoretta_cdn

The fact that he says the VR does not come with cables indicates to me that it is not a replacement since the cables are integral to the VR.

So I sent this message:

Thank you for your response. I am confused and
maybe looking at the wrong thing. When I went to
Athens and looked up the part under MP3
250/Electrical & Anti Rolling device it lists the
voltage regulator as part no. 58086R-37
I do need one for my mp3 250 and would buy yours
but just want to make sure I am buying the right
thing. Do you have a better picture you could put
up? Thanks in advance. Not trying to be a pain.

That was 2 days ago and I still have not received a response.

Let me know what you get and good luck.

Thanks for the heads up, sticky. I've sent them a link with a picture of the proper VR.

Is the part of the VR that attaches to the frame metal, or potted epoxy? If it is metal, is there enough contact area to justify the use of heat conducting grease when you install the new one? Also, is there enough space around the VR to consider extra heat sink(s)?

I like the way you are thinking here. Where the bolts go through it is metal to plastic but the majority of the rear of the VR is epoxy so I don't think heat conducting grease is an option. There is a lot of extra space to the rear and a little forward. Not much between the tupperware and the heatsink.

A wiki for removing the VR.

MP3 250: Removal of the voltage regulator

Broke down and ordered a new one from Athens scooter yesterday...should be here in 7 to 10 along with a bunch of other parts.

Nice how-to, Sticky. Be glad your VR is in such an accessible location!

The $35 MP3 voltage regulator I bought on eBay was, in fact, the incorrect regulator as stickyfrog suggested. Despite my contacting the seller, motoretta_cdn, prior to shipping and asking that he check for the proper part number and verify that the VR had the attached wiring, he sent the incorrect part.

We have since reached a resolution which will return all my payment including shipping. However, I'd suggest doubly making sure you're getting the proper part before taking advantage of the apparently good deals on eBay from seller motoretta_cdn.

From official troubleshooting guide:

PRELIMINARY RECHARGING SYSTEM CHECK
Recharge efficiency can be briefly checked by connecting the
multimeter with voltmeter function to the battery poles.
Take note of battery voltage in the rest condition and then start the
engine and accelerate progressively up to 3000 rpm.
If the recharging system is efficient, battery voltage increases
progressively up to 13.5÷14.5V.

If battery voltage goes over 15V, replace the voltage regulator.
If the battery voltage is the same as the value measured in the rest condition and the previous checks
(static) were successful, disconnect the voltage regulator and check that there is alternating voltage on the
connector coming from the stator either with the engine at idle speed or at 3000 rpm.
With the engine at idle speed, the alternating voltages measured between each phase with the other two
must be the same or similar (the difference must not exceed 20%).
Idle speed must be stable to obtain a reliable result.
If no voltage is measured between the phases, repeat the static checks on the stator.
If alternating voltages far below 10V are measured at idle speed, repeat the static checks on the stator and
check efficiency of the magnetic flywheel rotor.
If alternating voltages higher than 10V are measured at idle speed, repeat the battery voltage check using
a new voltage regulator.
If the battery recharge voltage is lower than normal even with the new regulator, first replace the stator,
then verify whether the three phase short-circuit current check confirms the stator fault.
To check, remove the voltage regulator connection and plug in three cables with their terminals.
Stators can be star or delta connected which is why short-circuit connection must be done in two different
ways.

yup I contacted them also and they said the would take another pic so I could see it better. that was the 2nd email and haven't heard back from them yet.

Yeah they never responded to my follow up email either.

Update in case you were following this and didn't see my other post. Put the new regulator in and problem solved. Lucky that the regulator is so easy to get to on an MP3 250...I understand this is not the case on other piaggio models. Thanks for all the input on this and especially thank you DougL.

My check engine light on my 07 MP3 is coming on as soon as I reach 6000 RPM's. It stays on until I shut off power then it stays off until I reach 6000 RPM's again.

I took it to the dealer and they said they cleared a few code and tightened a battery cable. I had them do an oil change/service. It ran fine for about 10 miles at about 70mph. Then, the light came back on.

The MP3 sits alot as I don't have much time to ride it and have been avoiding riding it until the check engine light issue is resolved. Don't want to harm it by riding it with the light on if there is something serious wrong.

The dealer I took it to claims to be a Piaggio dealer but I think they dabble in it and sell more Vespas but mostly motorcycles and ATVs.

Do you think if I replace the voltage regulator it would resolve the issue? Where is the best place to order one? I am not real mechnical but I think I could follow the post directions.

Thank you stickyfrog for posting these pictures and descriptions; without your and Zinfan's pictures this job would have been way more difficult. The Voltage Regulator sticky would benefit if the body panel removal procedures that Zinfan had put in his painting thread were added. I was having about the same problem as you and others described, engine light on at higher rpm's, excess voltage to the battery, and an odd noise like "marbles" rolling around in the Variator. I have read that same "marbles in the variator"reference on the Vespa GTS250ie when the Voltage Regulator fails. It took several weeks but Athens Scooter finally came through with the new Regulator, by then it was Winter and the MP3 was in storage. Today it came out of storage, and has a new regulator. Runs good, no engine light, no marbles noise.

Glad it was of some help and glad you are up and running.

Question about the vr. Please don't get out the rather large hammer when or if answering. I was wondering as reading all of these post and got the thinking about all those that add more mods than the vr can handle resulting in a low battery. Could you tea of the hot line going to the vr and place a second vr and use it to feed some of the mods, seeing as the alt puts out 30 volts and steped down to 14.5. Then you would have two different vrs to feed your needs? This is not my area, but I'll bet there are those of you who would know. Just a silly question. .

The capacity of an alternator is expressed in watts; the more accessories the more watts it takes to run them. The voltage regulator/rectifier steps alternating current from the alternator down to around 14 volts direct current to run the ignition, charge the battery, and run the accessories.

The charging system in a 400/500 has roughly 12A spare capacity with a tip-top electrical system.

Without this diagnosis I would probably still be standing in the Garage wondering what was wrong or be at the mercy of a dealer to fix it. Thanks DougL.

If anyone in need of a rectifier/regulator I've order one for mp3 500 looks like I don't bneed it.as it turns out it was voltage regulator fuse had gone so any one can have it cheap £50.00 plus postage

I had the same problem with the check engine light coming on at higher RPMs on my 2008 MP3 400. Found this post, ordered a new voltage regulator from ebay which was $150 cheaper than the OEM part. Installed it two days ago and no check engine light. So relieved because I don't think there is a service shop for MP3s anywhere near me. I also can't think of any other bike I'd rather have. Over 10 years later and this post/forum is still helping people so THANK YOU to everyone who has made such great contributions!!!

Ding! Here's another one.

Light coming on and off. 18 volts while motoring.

Guess it's time for a regulator.

Balked a bit at paying $190 for genuine so I ordered a chinese one for $45.00 to fit an aprillia. Had my doubts about how long it would last so got a 2nd one as well it has been working fine for the last year and I still have my spare. It was identical to the one I burnt out complete with the correct terminals on each end. Prices for genuine seem to be straight out extortion. Also replaced the hydraulic switch on the roll lock with a standard brake pressure switch at $15 instead of the stupid price piaggio wanted.

So glad this early post when I was in my infant stage with Piaggio products has helped so many. DougL spotted it early from my description and had I been a bit of a better mechanic I would have had it running a lot sooner.