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MP3 400 IE
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Location: Somers, CT
 
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MP3 400 IE
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Hi,

I am new to the forum. I recently aquired a 2009 MP3 400 IE. I have owned many scooters in my time and have always been fascinated by the MP3'S.

This machine is like new with only 1000 miles and had never been in the rain and stored in a heated garage. It has been used very little over the last few years.

I have changed the oil and purchased a new battery. I have driven the scooter a few times covering some 30 miles; however I currently cannot start the scooter. The battery is fully charged and I have tested the starter relay, starter and start button for power and everything checks out fine. All fuses are good. When I turn the key everything comes to life as it should and works fully. When I hit the start button nothing happens. No clicking or noises. On rare occasion it starts right up and runs great; however, most of the time it does nothing when I press the start button.

I cannot locate the starter as I want to check the ground wire. Any help is appreciated. I contacted both the hot and cold terminals on the starter relay and it triggered the starter.

I have invested many hours and have become frustrated as I want to ride this beautiful machine. As last resort I will take it to the dealer, which is 1 and 1/2 hours from my house.

Can someone on the forum advise on other things to look at?

Thanks for the help
@kawzak avatar
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Addicted
New 2023 BV-400
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Location: S. Texas
 
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@kawzak avatar
New 2023 BV-400
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You have to pull in one of the brake levers before pushing the start button. Seat switch. If your not on it when starting. Some others will chime in I'm sure.
@14perry avatar
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MP3 400 / BV250
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@14perry avatar
MP3 400 / BV250
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Brake switches or kill switch are the usual problems. Seat sensor does not come into play. You can start it while standing next to it.
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Hooked
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Hooked
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it sounds like something simple. and I agree brake lights not coming on or kill switch needs looking at.
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Veni, Vidi, Posti
2007 GTS
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Veni, Vidi, Posti
@old_as_dirt avatar
2007 GTS
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Location: Harriman, Tennessee, Tn
UTC quote
do your brake lights come on when using the brake levers? front? rear?
OP
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Member
MP3 400 IE
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MP3 400 IE
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The brake lights both come on and there is power to the kill switch. Could the kill switch still be bad even though there is power to it?
OP
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MP3 400 IE
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MP3 400 IE
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This is very strange, I am getting full power to the start switch with the kill switch set in either on or off modes; however, nothing happens when I push the start button. Could I have a faulty on/off switch?? I am following all of the prescribed start up procedures per the manual but nothing happens when I push the start button.
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BV400, Primavera 150, Yamaha Zuma 125
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@jkj-fz6 avatar
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You could have a faulty start switch. Can you get to the wiring to substitute another switch?
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The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
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The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
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I repeat the question posed above - you are holding in a brake lever at the same time?

Have you checked all fuses? Does everything else work on the bike apart from the starter motor? Can you hear the fuel pump prime when you switch on the ignition?
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MP3 400 IE
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MP3 400 IE
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All fuses are good including the hidden 30A fuse on starter relay. I just checked the connections on the starter motor and discovered everything is very tight including the battery cables.

I did discover that the starter motor is not getting power. Could this be a faulty 'starter relay'?
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The Hornet (GT200, aka Love Bug) and 'Dimples' - a GTS 300
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It could be - but is it getting power? You really need to examine the wiring diagram to work out what's working (and perhaps what's not).
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BV400, Primavera 150, Yamaha Zuma 125
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joegundlach wrote:
All fuses are good including the hidden 30A fuse on starter relay. I just checked the connections on the starter motor and discovered everything is very tight including the battery cables.

I did discover that the starter motor is not getting power. Could this be a faulty 'starter relay'?
BTW, how do you determine that motor, relays and switched are "getting power"?
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MP3 400 IE
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MP3 400 IE
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I checked them all with a volt meter with the ignition on
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BV400, Primavera 150, Yamaha Zuma 125
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joegundlach wrote:
I checked them all with a volt meter with the ignition on
You could have a dirty contact in any of the switches or the relay, and your high impedance voltmeter would still read near the battery voltage (12v). Try using a 12 volt test lamp that puts a small load on the point you're measuring.

Have you tried spraying electrical contact cleaner into the switches?
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Veni, Vidi, Posti
2007 GTS
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2007 GTS
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did you check the hidden fuse or the spare?
⬆️    About 7 months elapsed    ⬇️
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Piaggio mp3 300lt
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Piaggio mp3 300lt
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hidden fuse
hi guys, not wishing to look stupid, but hidden fuse? I have a 300cc mp3 LT in the uk. do I have one?
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Aprilia Mojito 125
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No, it is only 500's problem.
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Piaggio mp3 300lt
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Piaggio mp3 300lt
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thank you
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MP3 400 / BV250
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Jah wrote:
No, it is only 500's problem.
400's have it too.

250 diagram should work for 300

http://www.wotmeworry.org.uk/manuals/Piaggio%20MP3/MP3%20250/MP3%20250%20Wiring%20Diagram.pdf
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Piaggio mp3 300lt
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Piaggio mp3 300lt
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thank you all.
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Kymco AK550
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One of my MP3s had exactly this problem. It was caused by a defective relay on the left hand side of the engine bay, yellow body if I remember correctly. This has to close before the main starter relay will operate.

I was able to remove the outer housing and clean the contacts with very fine emery. After this I made sure that the housing was sealed at the edges with insulating tape so that it would not be affected by moisture again.

Its not shown in all wiring diagrams but in this later one it is labelled "STARTER MAGNETIC SWITCH AVAILABLE".

Had no more trouble with it.
Forum member supplied image with no explanatory text
⬆️    About 7 years elapsed    ⬇️
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roadster wrote:
One of my MP3s had exactly this problem. It was caused by a defective relay on the left hand side of the engine bay, yellow body if I remember correctly. This has to close before the main starter relay will operate.

I was able to remove the outer housing and clean the contacts with very fine emery. After this I made sure that the housing was sealed at the edges with insulating tape so that it would not be affected by moisture again.

Its not shown in all wiring diagrams but in this later one it is labelled "STARTER MAGNETIC SWITCH AVAILABLE".

Had no more trouble with it.
I know this is a very old thread but you sir are a legend! My 2009/10 mp3 400 LT after lots of love and new parts (see other thread) decided not to start.

The fuel pump primes, engine management light goes out, immobiliser lights all go out, but nothing when pushing the start button. No clicks or anything!

Cleaned the start button, kill switch and checked the brake lights work but still nothing.

Getting grumpy and fed up I searched and found this thread.

I located the yellow relay under the seat and found it was very dirty and the connections were crusty. Some electrical contact cleaner and wire wool it came up like new.

Tried starting it with it removed and it presented exactly the same. Replaced it and boom! It fired straight up!

To be on the safe side I've bought a new starter button, kill switch and relay which I'll keep on hand should this happen again.

Here is the location of the relay. The parts catalogue states the bike uses x5 of these so assume the 4 located under the windscreen are the same.
(cleaned up) Yellow relay under the seat to the left of the engine
(cleaned up) Yellow relay under the seat to the left of the engine
Yellow relay details
Yellow relay details
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