Wildguzzi.com

General Category => General Discussion => Topic started by: chuck peterson on September 15, 2021, 07:44:58 AM

Title: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: chuck peterson on September 15, 2021, 07:44:58 AM
How? Please..

https://nh.craigslist.org/mcy/d/marlborough-2017/7380392918.html


(https://i.ibb.co/Xb7ZSR2/EE89-B5-E1-9843-469-D-A436-A099-C68-C8-BE2.jpg) (https://ibb.co/Xb7ZSR2)

(https://i.ibb.co/BN5gb79/98-ABCF9-E-A83-E-4-DBC-B40-F-EF72-DA3-B8-EAE.jpg) (https://ibb.co/BN5gb79)
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: radguzzi on September 15, 2021, 08:02:43 AM

My thoughts exactly...  And how could the damage NOT have been isolated to the right jug and piston only...

Wow.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: JJ on September 15, 2021, 08:10:57 AM
How the hell do you blow up a Stelvio in the first place....and what is a "hydrolock" only affecting the right cylinder?!?  :shocked: :huh: :rolleyes: :rolleyes: :shocked:
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: Wayne Orwig on September 15, 2021, 08:31:30 AM
Looks like a dropped valve to me. Maybe a mis-adjusted valve burned off the stem, or crashed into the piston and broke off.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: Mayor_of_BBQ on September 15, 2021, 08:48:58 AM
'bad gas' will not cause a 2cylinder bike with a single throttle body feeding both cylinders to blow up on one side only. poppycock
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: Mayor_of_BBQ on September 15, 2021, 08:51:34 AM
i know gas quality varies widely but I am always hesitant to believe people have poor performance or even less so, catastrophic failures, due to 'bad gas'...  what about the other hundreds of vehicles who filled up from the same batch at the same station on the same day??
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: bettythebear on September 15, 2021, 09:12:09 AM
bad gasoline

https://www.youtube.com/watch?v=Lk677khGbUI
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: 80CX100 on September 15, 2021, 09:14:41 AM
How the hell do you blow up a Stelvio in the first place....and what is a "hydrolock" only affecting the right cylinder?!?  :shocked: :huh: :rolleyes: :rolleyes: :shocked:

     I haven't opened the ad for details and I don't want to get into major controversial topics; but I have witnessed a used Stelvio for sale, that had suffered catastrophic failure, likely as a result of overly rich EFI mods as forewarned by none other than the man himself, Pete Roper.

      Quite a while ago, I looked at a low mileage used Stelvio at local dealer, it was a decent price. From the sales manager's notes the engine had been replaced with a new OEM engine under warranty due to engine failure (iirc bottom end), but when questioned about any mods, one of them included the modified ECU that Pete had described, so I passed on the bike.
 
     Pete has cautioned many times that some of the EFI fueling fixes on the market are very crude, doing nothing more than just throwing extra fuel over the whole rev range and can overwhelm the engine and it's ability to lubricate itself, ie extra unburnt fuel washes oil off the cylinder walls, contaminates the oil, the rings wear, the problem gets worse and the crank can burn out; if unchecked and enough fuel got dumped into the oil, could you possibly end up hydrolocked and blow the engine apart; from the pictures possibly so lol. :evil:

   
     fwiw 
   
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: Rough Edge racing on September 15, 2021, 10:06:47 AM
Has anyone here seen hydrolock damage in real life.?  Does it have the appearance of a lose debris  denting the piston crown?
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: John A on September 15, 2021, 10:11:59 AM
bad gasoline

https://www.youtube.com/watch?v=Lk677khGbUI



Litnin Hopkins https://youtu.be/o3SXKLas-ko
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: aklawok on September 15, 2021, 10:43:17 AM
 A hydrolocked engine will twist/break the con rod or piston blow the head or throw the rod clean through the case. this damage looks like a sucked valve. also notice the soot inside TB.
even if it was a hydrolock, it would require pulling the crank, full bottom end rebuild, not just a slap job with a new piston.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: guzziart on September 15, 2021, 12:32:40 PM
Has anyone here seen hydrolock damage in real life.?  Does it have the appearance of a lose debris  denting the piston crown?

Yep (on diesel engines) and the result was a rod through the block.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: twowings on September 15, 2021, 01:41:34 PM
Mr. Roper is the final authority, of course but I do know that unlike the old hotrod days you had better do some serious homework before you throw 'speed parts' at an EFI engine. The 1200 big blocks are pretty darn good from the factory with the occasional wart here and there so my fun money is spent on suspension, maintenance, good camping gear, and adult beverages.

If I need to go faster, I'll buy an Aprilia!
 
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: Moparnut72 on September 15, 2021, 01:59:24 PM
Looks like a dropped valve to me. My 2016 1400 dropped a valve at 543 miles just before I was to test ride it. New OEM engine from Piaggio and I bought it in July 2019. It has been trouble free for 14,000 miles except for a red triangle of death on the first day. The tech didn't get the electrical connector to the oil pressure sensor fully engaged. With that piston beat all to hell, sure looks like a dropped valve. Even if the piston and head were to be replaced I would still be leary of the bottom end.
kk
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: Wayne Orwig on September 15, 2021, 02:17:33 PM
I have seen bad gas destroy a motor. It was a heavily modified Subaru WRX, that had high compression pistons and the turbo pressure was bumped up. The 'bad gas' did not have the octane needed to prevent extreme detonation, or worse, pre-ignition, when he turn on full boost pressure. It shattered most of the ring lands.
OR, more likely, the WRX engine was just ready to explode from too much boost, and the gasoline was blamed for the problem.
Either way, the same gasoline in other cars at that station was fine in unmodified motors.

As for what a hydraulic lock looks like, it will bend or break rods, maybe break the crank. Maybe even separate the cylinder from the crankcase. But the top of the piston will likely still look perfect unless it maybe cracks the piston. And it is damn near impossible to get a fuel injector to squirt enough fuel to hydraulic lock it.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: redrider90 on September 15, 2021, 02:26:03 PM
Has anyone here seen hydrolock damage in real life.?  Does it have the appearance of a lose debris  denting the piston crown?

I have seen 2 engines that hydro-locked. One was a 72 HD Super Glide FX. The guy ran it into a creek with the throttle open. He must have had the rpms up because the engine took enough water that it broke off both cylinders at the base of the cylinders where the attach to the crankcase. If my memory serves  me there are 4 bolts and the bolts didn't break but the cylinders broke. And the base of the cylinders were sitting up off the crankcase about an inch. 
The other case was my Murray lawn mower that leaked gas into the crankcase while sitting for a week. I started it and it sounded strange. And then immediately after sounding strange it blew the connecting rod through the crankcase just below the starter.
Cannot imagine bad gas blowing the top of the head off the cylinder. Gotta wonder what the innards look like in the engine.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: skippy on September 15, 2021, 02:35:57 PM
I have seen bad gas destroy a motor. It was a heavily modified Subaru WRX, that had high compression pistons and the turbo pressure was bumped up. The 'bad gas' did not have the octane needed to prevent extreme detonation, or worse, pre-ignition, when he turn on full boost pressure. It shattered most of the ring lands.
OR, more likely, the WRX engine was just ready to explode from too much boost, and the gasoline was blamed for the problem.
Either way, the same gasoline in other cars at that station was fine in unmodified motors.

As for what a hydraulic lock looks like, it will bend or break rods, maybe break the crank. Maybe even separate the cylinder from the crankcase. But the top of the piston will likely still look perfect unless it maybe cracks the piston. And it is damn near impossible to get a fuel injector to squirt enough fuel to hydraulic lock it.

In this particular example it sounds like who ever built this moto with more boost and compression didn't consider the need to open up the ring gap on the piston rings. The rings expanded to the point of interference, seized in the bore and took out the ring lands. Most modern engines can adjust timing to accommodate slight variations in fuel quality.

Just my 2 cents.

Skippy
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: HarveyMushman on September 16, 2021, 06:26:31 AM
'bad gas' will not cause a 2cylinder bike with a single throttle body feeding both cylinders to blow up on one side only. poppycock

The Stelvio does not have a single throttle body.  But, yeah.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: s1120 on September 16, 2021, 06:54:32 AM
Maybe he named the valves, and the one that it ate was called Hydro?   :grin:


Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: brider on October 01, 2021, 04:37:03 PM
So if the damage was NOT due to "hydrolock" or anything else that would otherwise also affect the left cyl, does a dropped valve or two on one side necessarily mean a bent rod or low-end damage? Tempting to think that the damage is limited to the piston/cyl only.
Title: Re: Blown up Stelvio, nh, cl, $2750 w fixes
Post by: Huzo on October 01, 2021, 04:48:28 PM
I’d give my left testicle to see the other piston crown... :popcorn: :popcorn:
Looks a bit like detonation. The only thing that turns me away from the dropped valve, is the sheer number of collisions before shutdown. He would have had to have kept riding it for a short time on one pot.
In addition, when carnage like that has occurred around the piston crown and smashing valves, I’m concerned at what the rocker arms think when they go to depress a valve and that valve is not free to move.

BTW..How come every time you see a blown up Guzzi, it’s got 8 valves...(or used to... :rolleyes:)
Has anyone seen the head ?
If I lived in the ‘States, I’d have it by now and put y’all out of your misery.