Modern Vespa

It was difficult to see the extreme base of the insulator but what I could see was the same as shown on the tip (photo).

The same day and prior to taking the bike back to the dealer, I was instructed by the dealer to disconnect the plug connecting the lambda sonder and run the motor to see if this made any difference, no change.

I only ran the motor at idle for 2-3 mins, I don't know how the signal from the lambda sonder effects the running during start and warm up.

No fail was indicated on the dash when the sonder was disconnected.

I agree , cannot see much of the insulator, but the electrode itself shows some carbon like build up and the outer surface has the same at the base of the threaded portion. Kind of an oily sheen to my eye. That's what leads me to think a rich mixture.

What I don't understand is why or how it can be too rich or too lean. My understanding of the computerized fuel injection system is that it automatically adjusts for this.

Unless there is a base circle timing issue ??
That's above my pay grade though

I am interested to hear what the dealer with all the magic computer testers has to say.

An air leak in the inlet manifold after the throttle body would lead to a lean condition and very hot running.

Bingo !!

I had not thought of an air leak.

I agree. That would make a lot more sence than the Timing being off. I`m sure the Mechanic would have noticed that the Timing was off.

only lean means more complete combustion. I could lean my cars out to about 17.5 to one. without issue at idle or part throttle. leaner would results in lean miss fires.

leak at intake manifold will just result in stalling at idle.

this will be retarded timing. seen it, diagnosed it a few times.

its also gonna be mechanical timing. as its very unlikely ecu is throwing the wrong timing suddenly. something loosened or skipped that controls timing.

Update.

The dealer is waiting for answers from Piaggio Italy, they are looking at data files sendt from the dealer, the dealer has not had any reply yet.

Looking at yr FC,its like super saving!like impossible.almost like 30km/l?i am only getting around 21km/l.
So its like u r running suoer lean?

Can't speak for model year 2019, but all previous years of the Master motor used the NGK CR7EKB spark plug. I know for a fact the 2018 500 hpe motor uses the CR7EKB.

Sometimes computer controlled injected engines behave in strange ways, especially if you stray from the stock ignition and fueling components.

I'd say just put in 2 of the CR7EKB plugs and see what happens. You'll probably want to disconnect the battery for a few minutes too just to clear the ECU while installing the plugs.

Then report back.

The dealer has the bike now, and is in touch with Piaggio.

The plugs are an iridium alternative.

I can tell you from decades working on cars, iridium and other "high tech" plugs do very little other than lightening your wallet.

Unless your vehicle was designed to take such a plug and the factory specifies such a plug, they almost always cause more harm than good.

The main purpose of Iridium plugs is extremely long intervals, like 100K+. But using high tech plug where a normal plug is specified usually causes stress on the ignition components such as the coil(s) or other strange behavior.

I bought the scooter new and the plugs I have where fitted as delivered.

please explain how that is possible for the plugs to put strain on coils.

I meant electrical resistance (strain), not physical strain.

It is far easier for a spark to jump the gap on a dual electrode plug with a standard type center electrode.

When using a iridium type plug with a very tiny center electrode tip, the spark has a tougher time and only a single tiny point to make the jump unless the other components (such as the coil) are beefed up to complement the iridium (or Yttrium or others) plug. That is what I meant by strain.

The standard CR7EKB has 2 points for the spark to ignite. The high tech plugs only have just one, and then only to said very tiny center electrode. I have not come across a Iridium or other high tech plug with multiple electrodes.

If combustion does not occur and/or burn fully, the remaining unburnt gasses will find their way into the exhaust manifold and burn there.

I've worked on cars (Mercedes mainly) for 40+ years, and using modern tech plugs on older engines has always caused problems, sometimes even causing ignition system failures due to use of non specified plugs.

In the case of the Piaggio Master motor, keep in mind that this motor dates back to at least 2005 and possibly even a bit earlier. It is a very old design engine that has been given a few tweaks as the years passed to keep looking fresh but it is a design that is very old and very conventional by nature.

still have not explained how the coil can be strained electrically.

Look the coils have a set value to produce period. they intern supply energy to the spark plugs, the coil don't care what's at the end of the line to receive the energy they GIVE out. The spark plugs do not provide feed back to the coils saying I need more I need more give me more energy.

you guys are both right.

iridium plugs require less energy to fire.

old cars may not run well with them. older engines dont burn as cleanly so iridiums tiny tip foul out very quickly. I have experienced this as well.

The issue is most likely to be a tight exhaust valve which is sending burning gases directly into the exhaust downpipe while it is still burning. It's come from the factory like it. I've seen this on one other bike some time ago. The gap doesn't have to be out by much to do this. It will also make the bike spite and burble to on the over run. The closed loop system will compensate as much as it can and often diagnostic readings can look pretty normal. It's unlikely to be a timing issue.

You mean too lean! Too lean burns hotter. Too rich runs colder.

I'm pleased to say this is not true. In all testing that we did we found that not to be the case and irridiums plugs and similar did prove useful and not harmful in any way. And as the manufacturers will tell you, what you are saying is largely pants! The only time cdi/coils are "strained" is when owners let their spark plugs go well over the normal change times. Doing that increases the resistance inside the spark plug and this requires more voltage to fire the plug. Your bike of course will not be able to supply more voltage. This also "strains" your cdi/coils and they run hotter leading to earlier failure. You will also get a smaller spark and lower performance and poorer economy. However, if we are talking "high performance" cdi/coils, these are designed to produce more voltage. But we are not talking that situation here. Even so, engine designers build in enough capacity to the electrical system on bikes or any engine to cope with normal wear and tear of spark plugs and cope with normal increases in resistance inside the plug. But importantly, not if owners go over the spark plug recommended change times.

The standard voltage needed to "fire" a spark plug increases with age. This happens because the "resistance" inside the plug increases exponentially as the plug ages. Typically, the voltage needed to fire a plug at 20,000 miles can be more than double that of what is required at 10,000 miles in order to give the correct size healthy spark. The cause of this is the insulation inside the plug breaks down causing extra resistance as the miles go on so requiring more voltage to fire the plug. The wear on the spark plug tip is surprisingly not so important unless it is very worn. Unfortunately, your bikes electrics under conditions of a very worn plug will max out as it cannot give more voltage so this "strains" the cdi/coils and can make them run very hot, eventually leading to early failure. In addition, the spark at the plug electrode tip will be smaller as it doesn't receive optimum voltage. This reduces performance and economy. If the plugs are not changed, eventually the plugs will misfire and fail.

The spark plug electrode tip is not a good indication of how worn out a spark plug is. A perfectly good looking tip may be on a completely worn out plug if you measure the voltage needed to fire the plug. It's internal insulation my have broken down by some way causing an increase in resistance so the bike cannot supply enough voltage in order to fire the plug with a nice fat spark. That's why it's important to change the spark plugs at the recommended intervals.

We found fitting irridium spark plugs gave the cdi/coil units an easier time. The fitting of some other radial firing plugs can be different depending on the engine they are fitted to. How hard the cdi/coils find it to fire a plug is dependant on several things, but in the main it's the compression ratio, and how worn the plugs are. Fitting a radial firing plug (often referred to as a sports plug) can be fine in many engine with no upgrade to the electrical system. On other high compression engines that may not be the case because the compression ratio raises the resistance to firing a spark plug of any kind. Therefore a upgrade to the eletrical system is needed to gain reliability. I think that is what sbaet is getting at and it's an interesting point he has made.

That's right Stromrider I meant to say lean not ritch My bad!

Yeah, I know you did. You have good knowledge....

Update

The data files viewed by Piaggio did not indicate anything that could cause the overheating.

Piaggio have stated the problem could be a faulty ecu even when the data did not show any problems.

The dealer is going to install a new ecu.

The dealer will also inspect/take photos of the cylinder walls, valves and valve seats using an internal camera/endoscope.

I am with stormrider on this one.
tight valve clearance is most likely
air fuel compression leak, burning in the downpipe
fits my diagnosis. its mechanical. its fuel burning at wrong time in cycle.

Yes it is possible, and "maybe" a fault with the de-compression system causing the incomplete closing of the exhaust valves.

The dealer is following instructions from Piaggio.

The last 14 days we have had beautiful riding weather and all I have done is wax and polish my riding boots, and now they gathering dust.

I wouldnt hurt to call them and give em a nudge in the right direction.

what one needs to understand about service is just because its the dealer and they sell the bike doesnt mean they are gonna be full of repair knowledge. there is just not that much repair work being done on scooters. I feel sorry for anyone who has a vespa dealership in tampa. tampa is a pretty large area yet there is just not enough market. barneys of tampa laughed at me when I asked why they were no longer a vespa dealer. "we sold like four vespas a year" was their response. they were glad to be free of it.

Also, when dropping a bike off that is your main transportation, let the dealer know that is how you get around. We use to push daily riders to the front of the line if we could.

The dealer is a Vespa/Piaggio specialist and has been selling scooters for 20+ years, I don't know how many MP3's they have handled.

The first service on my scooter they included re-torquing/greasing the steering stems, the workshop seems well equipped.

At the moment I have to rely on their competence, i'ts just taking a laaang time

Oh goody! A new film I need some Popcorn !

Here is another
[urlhttps://www.youtube.com/watch?v=5WnM_NsOtd8[/url]

Me thinking ,

The throttle and the throttle position sensor are pre-calibrated at the factory.

If the throttle position has NOT been calibrated correctly maybe slightly wide (open) and the ecu reset to to match what it assumes is the correct minimum throttle position, the mixture at idle and small throttle openings would be lean, less obvious at wider throttle openings, maybe.

Just checking the thread to see what the results were on this problem.

Keith,
Marietta, GA

No result yet, I've not had anything new from the dealer.

Ok, Thanks...

Do you have a 'Lemon Law' in Norway?
Keep accurate records, dates, who you spoke with, etc..
If they don't fix it this time, keep bringing it back.
Seems like you're already at or near 30 days without your vehicle.

The dealer has received the "parts" and will start replacement, if this solves the problem I don't know yet.

I do want to see internal photos of the cylinder/piston top and valves, if the condition is comparable to an engine that has done 2600 kms ok, if not????

parts what parts? what did they say?

I think they are replacing the ecu, I called them yesterday and they said they had "just received the parts from Piaggio"

Interesting????
I hope this works, I can't wait to see the resolution to this one.

Keith,
Marietta, GA

I have called the dealer, they have changed the ecu, no change!

The dealer told me that on information they have received from Piaggio/importer that the red hot header on my MP3 is normal for eu4 engines!

No photographs are available.

I have asked for written confirmation from Piaggio describing the condition as normal.
I will not collect my MP3 before I have a copy of the above.

Very frustrated, can't understand the header can be so hot after only 2 mins from cold start, (ambient temp. 6 deg.C)

I am concerned that the high temp. could cause further damage.