Engine failure

[URSUS]

If the balancing gear lost its teeth, and I modified its rotation, it is easy that the connecting rods would have hit the counterweights of the balancer. What if the starter motor failed / broke and this started the teeth breaking?

View attachment 81292
If the starter anchor bolts are lost or loose ... I think it sets off a cascade of breaks

Thanks for this, as everyone else has stated, it’s a great video. The starting motor is in perfect condition, the bike actually fires up every time, the engine runs, just won’t go above 4000Rpm. It’s the crank rods that broke, and they can’t figure out why, how, where, what could have caused it. I wish I would have taken a video of it when it first happened. I do have a small clip, mainly for the sound effect, but can’t load it here for some reason. Daddy Yamaha now wants a deeper investigation, so that may well be forthcoming for me , fingers crossed

 

[WJBertrand]

Wait, you’re saying it will run up to 4000 RPM with broken con rod? That’s very surprising, a broken connecting rod will usually lock up the engine or punch a hole in the crankcase.


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[Sierra1]

Wh-a-a-a-at?! Just to make sure we're talking about the same thing. . . . connecting rod. . . . the hunk of metal that connects the piston to the crankshaft. . . . is broken. . . . and the motor is still able to start, and run?! I have to be misunderstanding something.

 

[URSUS]

Wh-a-a-a-at?! Just to make sure we're talking about the same thing. . . . connecting rod. . . . the hunk of metal that connects the piston to the crankshaft. . . . is broken. . . . and the motor is still able to start, and run?! I have to be misunderstanding something.

Wait, you’re saying it will run up to 4000 RPM with broken con rod? That’s very surprising, a broken connecting rod will usually lock up the engine or punch a hole in the crankcase.


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I’m guessing at that time, prior to them stripping it down, yes it ran. There is no damage to the crank case, ( so they tell me). The song it was singing was like, the cct had snapped or came loose, and was hitting something, however that wasn’t the case. Cct intact. They even asked me if someone could have poured ball bearings in the oil filler spout ( Which I thought was odd). Since I explained that I was doing about 80 mph for a good 30 mins prior to hearing that sound, they ruled that out. I haven’t seen the actual crank rods, but that’s what they are saying broke. Or should I say, they think 1 broke causing an ELEPHANT EAR, which was probably the sound I could hear. I’m guessing that 1 broken shaft ( And I mean the shaft, not the circular housing, it snapped on the straight bar piece) caused the dividers to go into meltdown, breaking the other shaft and throwing several parts around the crankcase and so on. I’m sorry that I’m not as technical as the rest of you, and I will try to get some pics and videos on Tuesday when I go to see them again.

on another note, does anyone know if this motor would be a suitable replacement? It’s from Canada and an XTZ E

EB816 2015 15 YAMAHA SUPER TENERE XTZ1200E ENGINE ASSEMBLY | eBay

YAMAHA XTZ1200E. Listed by: JD. We are located in Nisku, Alberta, Canada. Paste link into a browser window:[isdntekvideo]. Video will open in a new window.

www.ebay.com

 

[WJBertrand]

What’s an elephant ear? Been around motors a lot and have never heard that term.


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[Jlq1969]

What’s an elephant ear? Been around motors a lot and have never heard that term.


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must be the counterweights

 

[URSUS]

must be the counterweights

That’s the term they use for When the cams on the crankshaft move in a similar way to an elephant ear rather than the way they are designed

 

[Sierra1]

. . . .on another note, does anyone know if this motor would be a suitable replacement? It’s from Canada and an XTZ E

EB816 2015 15 YAMAHA SUPER TENERE XTZ1200E ENGINE ASSEMBLY | eBay

YAMAHA XTZ1200E. Listed by: JD. We are located in Nisku, Alberta, Canada. Paste link into a browser window:[isdntekvideo]. Video will open in a new window.

www.ebay.com

I'm pretty sure that would be a yes. But, message TABASCO to confirm. Back to the failure. So, when it happened, you turned it off. . . . it didn't stop on itself?

 

[~TABASCO~]

I’m guessing at that time, prior to them stripping it down, yes it ran. There is no damage to the crank case, ( so they tell me). The song it was singing was like, the cct had snapped or came loose, and was hitting something, however that wasn’t the case. Cct intact. They even asked me if someone could have poured ball bearings in the oil filler spout ( Which I thought was odd). Since I explained that I was doing about 80 mph for a good 30 mins prior to hearing that sound, they ruled that out. I haven’t seen the actual crank rods, but that’s what they are saying broke. Or should I say, they think 1 broke causing an ELEPHANT EAR, which was probably the sound I could hear. I’m guessing that 1 broken shaft ( And I mean the shaft, not the circular housing, it snapped on the straight bar piece) caused the dividers to go into meltdown, breaking the other shaft and throwing several parts around the crankcase and so on. I’m sorry that I’m not as technical as the rest of you, and I will try to get some pics and videos on Tuesday when I go to see them again.

on another note, does anyone know if this motor would be a suitable replacement? It’s from Canada and an XTZ E

EB816 2015 15 YAMAHA SUPER TENERE XTZ1200E ENGINE ASSEMBLY | eBay

YAMAHA XTZ1200E. Listed by: JD. We are located in Nisku, Alberta, Canada. Paste link into a browser window:[isdntekvideo]. Video will open in a new window.

www.ebay.com

Yes, it should fit and “plug in”. If you have to do the work I can give your some pointers if you like. I’ve done it before -

(that motor is super heavy on its own, 2 people unless your extremely strong)

 

[~TABASCO~]

After reading this, I’m “wondering” if this is more like a broken balancing shaft? I’ve not seen any motor break a con rod and still run to 4K or no absolute distraction of block, cylinder, piston, Etc. This doesn’t sound like a ‘rod’ but who knows.
Major broken parts and still fires up and runs to 4K has got me stumped. I need a good mechanical mind bender once and awhile.

Looking forward to any photos or final yamaha report. I’m sitting on the edge of my chair waiting to read or see this eventually.

 

[WJBertrand]

That’s the term they use for When the cams on the crankshaft move in a similar way to an elephant ear rather than the way they are designed

Cams on the crankshaft?? Now I’m even more confused. I still can’t visualize any movement that would resemble elephant ears…


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[URSUS]

Yes, it should fit and “plug in”. If you have to do the work I can give your some pointers if you like. I’ve done it before -

(that motor is super heavy on its own, 2 people unless your extremely strong)
View attachment 81326

Thank you Sir.

 

[URSUS]

Cams on the crankshaft?? Now I’m even more confused. I still can’t visualize any movement that would resemble elephant ears…


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I meant fly wheels, sorry.

 

[URSUS]

I meant fly wheels, sorry.

I found this to explain the elephant ears.

 

[URSUS]

That’s the term they use for When the cams on the crankshaft move in a similar way to an elephant ear rather than the way they are designed

Flywheels not Cams.

 

[BaldKnob]

Apparently, correct nomenclature is very important around here!

Good luck with Yamaha helping resolve your problem. I’m sure they’ll want to discover why things went awry in there even if your bike is out of warranty.

 

[WJBertrand]

I found this to explain the elephant ears.

Thanks for that, learn something new everyday! The “elephant ear” phenomenon sounds like it’s not a description of the failure itself, but rather something fundamental in the design that can lead to a failure, in Kevin Cameron’s example a cracked/broken crankshaft as opposed to a con rod. If this excess motion is a fundamental weakness for this engine I would have expected to hear of this kind of failure before. I think this is the first reported case, and believe there’s more to this story!


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[Sierra1]

Apparently, correct nomenclature is very important around here! . . . .

It's bound to happen. There's members from all corners of the US; we cant even agree what to call carbonated soft drinks. And, then throw in other countries. It's pretty surprising that we're all not asking what did he say/mean on a daily basis.

 

[Clawdog60]

Thanks for this, as everyone else has stated, it’s a great video. The starting motor is in perfect condition, the bike actually fires up every time, the engine runs, just won’t go above 4000Rpm. It’s the crank rods that broke, and they can’t figure out why, how, where, what could have caused it. I wish I would have taken a video of it when it first happened. I do have a small clip, mainly for the sound effect, but can’t load it here for some reason. Daddy Yamaha now wants a deeper investigation, so that may well be forthcoming for me , fingers crossed

you will be getting a new drive train from them. when? well that's the million dollar question

 

[Clawdog60]

Thanks for that, learn something new everyday! The “elephant ear” phenomenon sounds like it’s not a description of the failure itself, but rather something fundamental in the design that can lead to a failure, in Kevin Cameron’s example a cracked/broken crankshaft as opposed to a con rod. If this excess motion is a fundamental weakness for this engine I would have expected to hear of this kind of failure before. I think this is the first reported case, and believe there’s more to this story!


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Why I had the crank on my road king trued and welded