Great GRiSO Minds Needed for a V7 Problem :-)

Yes, I know it’s so demeaning for such lofty cranial masses as yours deign to concern yourself an engine issue on my Stornello, a mere small block.  

OTOH, think you’ll find these pix interesting enough to want to consider thinking about what caused them!


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Yikes, huh?  

I have had a number of posts and had follow-on comments about this on the long-lived ADVRider V7 thread, but, so far, we Seveners seem stumped.

As those of you who “go there” know, ADV threads can be all over the place, so there is not an unbroken succession of posts on this.  

Here, however, for your convenience if you care, are the primary posts I’ve made that also generally address subsequent comments along the way.

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And, here are some (not especially helpful) pix of the diagnostic process so far, but included in case you get suckered in and need more info.


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I would be grateful to have your thoughts and suggestions.

1921!

Bill

OMFG!

Bill, while re-checking the valves is a good idea I'd bet London to a Brick that the problem will be the plug caps. While I haven't trawled through the whole sorry saga yet the sort of symptoms and effect you are seeing is absolutely typical of the failed spark plug cap issue.

While this usually manifests itself on only one side as the caps are go in ing to fail independently there is absolutely no reason why they can't both fail at the same time. They really are the most atrocious junk and why Guzzi/Piaggio persist with them when the savings acquired by persisting with them when there are so many better options available for pennies more is enraging.

The reason the pipes are glowing up like that is a result of the bike 'Running like crap'! What has happened is that the caps have failed, most likely the resistor inside the cap has broken, (This is a common problem with 1400 plug leads/caps as well.) and I'll give good odds that if you pull the complete lead from the coil and measure continuity from the coil end to the plug terminal rather than getting approximately 8k-ohms resistance you'll find that the lead is open circuit. The other alternative is the cap has torn and the spark is simply arcing to earth.

Either way what will be happening is that you will be getting an intermittent spark and on the cycles of the motor when the mixture isn't ignited in the cylinder that unburnt mixture is expelled into the exhaust header. The next time the plug does fire when the exhaust valve opens the exiting hot gasses ignite the unburnt mixture in the pipe. It doesn't burn as hot as it does in the cylinder but it will still burn plenty hot enough to glow the pipes, especially on a Stornello which I believe has the single skin Arrow exhaust headers. Other models will do this too in the same circumstances but they all have double skinned pipes so you don't see the glow of the inner pipe but if run for long the burning mixture will glow up and destroy the catalytic converters in the exhaust silencer units. Pictures of bikes that have done this are legion on the interwebs.

Before you do anything else just junk the plug caps and fit NGK Bakelite caps. I can't remember the number offhand but I can find out for you if needs be. I'll give very, very good odds it will cure the problem instantly.

Wow, Pete!

What a thoughtful and helpful response conveyed in a manner that even a ham-fisted, untalented wrench such as I can understand!  Really.

Will find and order those NGK Bakelite caps right away.

May have to add a sub-label to the Moto Grappa: "The Pete Roper Virginia Branch Shop."  

Bill

My bet is with Pete. Many have severely blued a pipe from having a cap go south on them while riding a V7. Both at the same time? Still quite likely especially since they were recently pulled off. That may have been the last gasp for both of them.

MG Cycle has the correct caps.  http://www.mgcycle.com/index.php?main_page=product_info&products_id=5146

This also happened to me after the first service from the shop, the caps were damaged and had to be replaced.
The pipes became so hot they melted the starter cover and also turned the lagging inside the muffler into a melted blobby mass. Be worth while taking the muffler off and see if it rattles.

Bill, don't know if the Stornello is much different from the earlier 1TB V7, but my '14 came with CPR8EB-9 plugs. I wasn't happy with the connection the caps made with the solid top of the plug, and changed the plugs to (NGK) CR9EK and the caps to XD05F. This gave me both tactile & audible feedback that the caps properly connect to the threaded plug end. The bike's been running fine ever since ('tho now merely at 112,000km), even if it's a tad thirstier than the V7C (4.2 - 5.0 L/100k, as opposed to 3.9 - 4.5 L/100k), but that could be explained by other factors.

Although I never had your cherry red header syndrome, there were some combustion problems before the plug change (most likely due to "other factors"). When I mounted the single walled stainless headers on the V7C, I did note that they started to show evidence of the gold to brown colour transformation within the first 100 meters. The single-walled headers recently mounted on the 1TB for the first time were black painted stainless. Clouds of grey smoke started coming off when first started and idled, but that turned out to be the black paint burning in. The headers are now dark grey, fading to the more or less original satin black nearer the muffler.

What year is your bike?

The year is pretty irrelevant. All the single TB, heron head V7's are essentially the same and used the same shitty plug caps.

Suit yourself...

If both cylinders are doing that the cause is far more likely to be something common to both cylinders..

Ergo maybe not the plug caps...

But the plug caps are a well known failure point so it makes sense to try the easy, known, cheap, solution before rushing in to look for more complex, hidden issues.

Once again, all the single TB, Heron head models are essentially the same. The Stornello's only difference really is the Arrow pipe. Apart from that the engine is identical, the airbox and engine management system is identical, the loom and sensors are identical. The year is irrelevant. That's all I was saying.

Also the fact that the 'Check Engine' light hasn't come on would indicate that most likely it isn't suffering a sensor or ecu generated error, (Although that can easily be checked using Guzzidiag.) all of which points to an accessory error and the known fail point of the caps means that that is the first place to point the bone. The caps being the problem would also produce exactly the symptoms observed.

It may not be the caps. It may be some weird and arcane issue that will leave us all stumped! But I think the likelihood of that is low whereas the chance it's the caps is very, very high.

Spalders wrote:

Suit yourself...  

If both cylinders are doing that the cause is far more likely to be something common to both cylinders..

Ergo maybe not the plug caps...  

Understandable comment about "both at once," especially in routine riding, etc.  

That said, in this instance am inclined to think it is exactly that.  Recall that this "cherry orchard" happened at first start-up after a maintenance session that included removing both caps, pulling (but not replacing) plugs, and replacing caps.  All that was done by a very experienced Guzzista, but one who had never been 'up close & personal' with a V7.

So, we shall see as soon as I can R&R the caps ... and (darn it) probably reinstall map.

[Attention Pete & Mark (& anyone else so interested in this piece)!   ] Jim Hamlin -- [You must be registered and logged in to see this link.] -- replied to my email asking him to send those caps that "What I've seen on 2013 + V7I/II with plug caps is that they will leak spark that grounds to the head and wipes out the tune in the ECU."

Oh, Spalders, 2016 V7 II Stornello.

Best,

Bill

Quote :

What I've seen on 2013 + V7I/II with plug caps is that they will leak spark that grounds to the head and wipes out the tune in the ECU.

Snurk!

beetle wrote:

Quote :

What I've seen on 2013 + V7I/II with plug caps is that they will leak spark that grounds to the head and wipes out the tune in the ECU.

Snurk!

Hmmmm. Can't find "snurk" in my "Modern Dictionary of Down Under Words Unknown by the Rest of the Planet," aka [You must be registered and logged in to see this link.]

I take it, however, that you mean that you hold Jim's view in some sort of derisive contempt.

Seriously -- tho that was -- I then presume that if indeed the caps are the villains, that I don't need to worry about any electrical surge (or whatever might be happening) from those damaging the map.

I'm down in the Moto Grappa hiding from carriers of the dreaded CV19 and fretting about my dead Norge and Stornello. I'd ride the GRiSO for therapy if it weren't raining and 39ºF outside. Blech.

Bill

Quote :

I take it, however, that you mean that you hold Jim's view in some sort of derisive contempt.

Not exactly. Perhaps a more apposite choice of words. Say, "potentially damage the ECU", or, "give rise to service warnings".

"Wipes out the tune in the ECU"? May as well have said: "zippy kapow go 'poof' in shiny box".

You blokes crack me up. Me likey funny shit!

Incidentally, Mark spends much of his downtime thinking of the "right" words to say. Usually hits the funny bone fair and square.

Bill you have yet to learn lots with the Australian vernacular - this is a caveat (there's always a caveat) and that is as soon as you think you've got it, it goes up a level.