MGX died and won't restart-UPDATE

[drbone641]

If the timing chain went south, a'la Luap's bike, at speed, could that have caused this issue?

[LowRyter]

If the timing chain went south, a'la Luap's bike, at speed, could that have caused this issue?

You'd think the valves would stay closed when the chain lost tension,  unless the chain was stuck when the valves were open.

[Huzo]

You'd think the valves would stay closed when the chain lost tension,  unless the chain was stuck when the valves were open.

You may be lucky enough for that to happen, but remember that the valves on one cylinder are only closed in unison while the piston is coming up on compression and on the power stroke.
Even then, the opposite cylinder will be at a different phase.
You’ll never have all valves closed at the same time.

[Lannis]

Very impressive for Piaggio to take such quick action and to ship a whole new motor. No idea why the valve dropped but none the less, congratulations to the dealer and to Piaggio.

Maybe the same problem that BMW and Norton and Triumph have all had .....

.... take an engine configuration designed in the 1930s as a 500cc with 25 HP, keep bumping and bumping and bumping the CCs to keep up with the neighbors, until you have a 750 or 850 or 1200 or 1400 with 100 HP, and wonder why rear drives and valves and cranks don't hold up?

One of those things that makes you say "Hmmmm...".   And you have to be an old man with a broad view to even see that whole train in one look ....

Lannis

[Don G]

What really has me going HMMMMM, is the fact that the engine has a mechanical failure and the operator is thinking dead battery? Like what was all that rattling and crunching going on just before the silence? DonG

[Huzo]

What really has me going HMMMMM, is the fact that the engine has a mechanical failure and the operator is thinking dead battery? Like what was all that rattling and crunching going on just before the silence? DonG

The battery breaking...?

[LowRyter]

You may be lucky enough for that to happen, but remember that the valves on one cylinder are only closed in unison while the piston is coming up on compression and on the power stroke.
Even then, the opposite cylinder will be at a different phase.
You’ll never have all valves closed at the same time.

My point was with a timing chain coming loose, that there wouldn't be pressure on the valves.  On the other hand, if the chain jumps the sprocket, it can go out of time and "crash".  I suppose that is likely outcome since I know folks that have destroyed a few of motors for that reason.

I'd say my original point was off base.

[bikeridertim]

What really has me going HMMMMM, is the fact that the engine has a mechanical failure and the operator is thinking dead battery? Like what was all that rattling and crunching going on just before the silence? DonG

If you read the original post you would see how I was doing about 70 miles an hour. And I also had a battery problem in  the previous weeks. All I can say is at 70 miles an hour with cars around you I wasn't paying a whole lot of attention to valves dropping, as it continued to run on one cylinder and thinking what the @#* is going on!

[Kiwi_Roy]

Well, it wasn't electrical, thats all I can say.

[oldbike54]

Well, it wasn't electrical, thats all I can say.

 

 Dusty

[Huzo]

Well, it wasn't electrical, thats all I can say.

Well it could be...
I once stopped to hep an old guy who’s car had broken down on the side of the road..
It was after dark and the relic was sitting there in a pool of black oil in pitch darkness, (the car, not the bloke..)
When I asked if there was something I could do to help, he replied..
“Oh I think I’ve got an electrical  problem..”
“Jeez, says I”, (looking at the tsunami of 7 year old crude running out from underneath...)” What leads you to that thought..”
“Well..” (says the old timer ruefully stroking his beard and staring at the carnage..)
“Looks like she’s thrown a con rod and it’s come out through the side..”
“How’s that electrical then..” ?
“Well (opines the old timer), it’s knocked the generator clean off it’s mountings..” 
Well alllrrigghhhttyyy then.....

[Murray]

Well it could be...
I once stopped to hep an old guy who’s car had broken down on the side of the road..
It was after dark and the relic was sitting there in a pool of black oil in pitch darkness, (the car, not the bloke..)
When I asked if there was something I could do to help, he relied..
“Oh I think I’ve got an electrical  problem..”
“Jeez, says I”, (looking at the tsunami of 7 year old crude running out from underneath...)” What leads you to that thought..”
“Well..” (says the old timer ruefully stroking his beard and staring at the carnage..)
“Looks like she’s thrown a con rod and it’s come out through the side..”
“How’s that electrical then..”)
“Well (opines the old timer), it’s knocked the generator clean off it’s  off it’s mountings..” 
Well alllrrigghhhttyyy then.....

Can remeber if his name was Allan grince or Win Percy per chance?

[Huzo]

Can remeber if his name was Allan grince or Win Percy per chance?

I heard it from Dick Johnson, but your point is well made Muzz...(bastard..)

[pat80flh]

If the timing chain went south, a'la Luap's bike, at speed, could that have caused this issue?

   I would say yes, absolutely.

[Big_Jim59]

If you read the original post you would see how I was doing about 70 miles an hour. And I also had a battery problem in  the previous weeks. All I can say is at 70 miles an hour with cars around you I wasn't paying a whole lot of attention to valves dropping, as it continued to run on one cylinder and thinking what the @#* is going on!

If the timing slipped and the piston just kissed and bent the valve the drama would have been minimal. The cylinder would have lost compression. The mystery is how was it running on one cylinder? A timing slip of that magnitude would have effected the other cylinder as well.

I would look closely at the valve spring. A substandard spring can crack allowing the valve to contact the piston.

[Peter949]

Thank you for posting the images that show the engine damage to your low mileage MGX. If they determine what caused this problem, please let us know with an update.



 

[Bulldog9]

Thank you for posting the images that show the engine damage to your low mileage MGX. If they determine what caused this problem, please let us know with an update.



 

Is that a picture of the head on this MGX? ??##$$??!!!! How the F does that happen? head dropped an intake and exhaust valve AND wiped out one of the spark plugs?

[guzzisteve]

I would 1st find out if they are 1pc valves or welded on heads to valve stem. Guzzi IS cheap.

[Peter949]

Yes, that is the original photo from the fellow with the MGX, that described the "dropped valves" in his engine.

[bikeridertim]

Well it's time for a update.
I got my MGX back on the 25th of April. New motor from Guzzi, I have put about 675 miles on her so far and am very happy with how everything is running.  (I was 14 months ago also) I have been told that the motor will be going to the Guzzi training center in CA for evaluation as to what happened. The dealership seems to think it was a broken two-piece valve. I will be staying in contact with the dealership for any more information. Now it's time for a set of tires, oil change and a summer of riding!!

[Bulldog9]

Well it's time for a update.
I got my MGX back on the 25th of April. New motor from Guzzi, I have put about 675 miles on her so far and am very happy with how everything is running.  (I was 14 months ago also) I have been told that the motor will be going to the Guzzi training center in CA for evaluation as to what happened. The dealership seems to think it was a broken two-piece valve. I will be staying in contact with the dealership for any more information. Now it's time for a set of tires, oil change and a summer of riding!!

Glad you got it worked out and motor swap went so quickly.  Quick question, I think that you said the dealer reported the lower plugs were damaged on both sides? Did it drop a valve on one side or both?

To the Guzzistas, which other models use a 2 piece valve stem? That's nukin futs............

[guzzisteve]

Nice update, now to find out what caused the destruction.

[moto-uno]

  Some one correct me if I'm wrong here , but valves are frequently 2 piece welded units .( Friction welded )
Some aftermarket companies ( Manley ) advertise that they make one piece stainless valves . Peter

[RinkRat II]

     You are correct Moto, two piece more common due to cost in materials.
 
     Paul B

[Moparnut72]

Keep us posted on what you find out about the valve problem. It would be good to know if I am still riding a time bomb. Did they have a problem with valves and if so did they upgade? I may need to invest in a backup. I need a good excuse to put a V7 in the garage.
kk

[bikeridertim]

Glad you got it worked out and motor swap went so quickly.  Quick question, I think that you said the dealer reported the lower plugs were damaged on both sides? Did it drop a valve on one side or both?

To the Guzzistas, which other models use a 2 piece valve stem? That's nukin futs............

Bulldog9,
It dropped a valve on the left cylinder and sucked debris into the right cylinder. If you see pictures from both sides it appears get it done it for a little bit. There was quite a bit of buildup on right side.

[bikeridertim]

Keep us posted on what you find out about the valve problem. It would be good to know if I am still riding a time bomb. Did they have a problem with valves and if so did they upgade? I may need to invest in a backup. I need a good excuse to put a V7 in the garage.
kk

I definitely will keep everyone posted.
Honestly I don't think it's a known problem,  actually I think it's a fluke. Only 1 other one that I have heard of, and it wasn't seen by the guy, just told "it dropped a valve" 

[Xlratr]

I think that dealer did a good job for you. They quickly identified the problem (6 hours after drop off) without the bike standing around for weeks and got the ok for a new motor. You were back on the road pretty quick in my opinion. Considering you were worried about their lack of experience I think they did you proud. Maybe you'd like to mention the dealer in case others are reasonably close?

[bikeridertim]

I think that dealer did a good job for you. They quickly identified the problem (6 hours after drop off) without the bike standing around for weeks and got the ok for a new motor. You were back on the road pretty quick in my opinion. Considering you were worried about their lack of experience I think they did you proud. Maybe you'd like to mention the dealer in case others are reasonably close?

I am VERY happy with how this turned out!!!!  You are right, They have done a GREAT job in my opinion!!!!

Team Charlotte in Charlotte NC is the dealer!   

[Moparnut72]

I definitely will keep everyone posted.
Honestly I don't think it's a known problem,  actually I think it's a fluke. Only 1 other one that I have heard of, and it wasn't seen by the guy, just told "it dropped a valve" 

I was also told by the manager who was ridind it said it instantly locked up.
kk