Recent odd failures on bikes that have come into my shop...

[mitt]

Discussion on questionable sss hub / wheel design versus perfect mechanical skills

http://ducatimonsterforum.org/index.php?topic=39092.msg694026#msg694026


mitt

[Speeddog]

Been a while since I added anything.

'08 1098 came in on a flatbed, ~14k miles, had started squeaking and quit running.

Not looking good already:



Nope, definitely not good:




And not getting any better:



Strained the oil:



Dug into the motor, not too bad, barely marked the journal on the crank.



Buuut, this is bad, scraped and hammered out to about half thickness, scuffed the crank quite a lot:



Special bonus; piston tapping the head in the squish area, all the carbon knocked off:



Second helping of dessert, rod was so loose that it allowed the piston to rotate enough that the exhaust valve was scraping the edge of the pocket:



Aluminum on the (most likely bent) valve:

[ducatiz]

No new shop stories at this time.

Fuel lines from the factory are good stuff, but it seems that allowing them to marinate in spoiling ethanol-laced fuel will kill 'em.

Believe it or not, a lot of fuel additives have rubber-eating ingredients in them -- use too much for the small gas tank and it could easily attack the rubber.

A lot of them (STABIL) use mineral spirits as an ingredient.  Mineral spirits eats rubber if left in contact long enough.

I can easily see some schmo putting a FAR too high concentration of Stabil in their gas tank thinking MORE IS BETTER and then that happening.

[thought]

This thread is awesome 

[Langanobob]

Been a while since I added anything.

'08 1098 came in on a flatbed, ~14k miles, had started squeaking and quit running...

...Nope, definitely not good:

Any thoughts on what caused that on a low mileage bike?  I've seen similar, but on real high mileage engines, or rod bearings that were set up with too much clearance to begin with.  Seems like even abusing it, would be hard to do that in only 14,000 miles.

Thanks for posting this stuff.

[zooom]

former race bike maybe?

[Speeddog]

Doesn't look like the bike has been raced.

AFAIK, it's on it's second owner, who knows the first owner.
Reportedly, the bike has never been down.

Probably a temporary oil starvation, too long a wheelie, or high rpm/load when cold.

Brain fade, doing an oil change and start the engine before refilling.

Oil seal on the crank end may have blown, I don't have the clutch sidecover off yet.

Perhaps I'll find the culprit.

[Duck-Stew]

That is a LOT of damage SpeedDog...

Are you going to rebuild, or replace the motor with a different one?

[Speeddog]

That is a LOT of damage SpeedDog...

Are you going to rebuild, or replace the motor with a different one?

Pending further inspection, current plan is to reload this round.

[NakedPastaRocket]

great thread, very informative.  Keep em coming Speeddog!

[Gimpy]

Out of curiosity, assuming there is no other damage to the piston, besides the valve scrape. Do you replace it? and why or why not?

[Speeddog]

Out of curiosity, assuming there is no other damage to the piston, besides the valve scrape. Do you replace it? and why or why not?

Need to do further inspection, as it was tapping the head.

It may have closed up the upper ring groove.

[Novelo]

Eh that 1098 makes me cringe, thanks for the post Speeddog.

[SpikeC]

 At this point not replacing the pistons would be a false economy, IMO.

[Speeddog]

An ST2 came in on a truck, no run condition.

Key on, fuel pump sounded not so good, more of a wuhhhhhhhhhhhh than the usual wheeeeeeeee.
Checked pressure, 15 psi instead of the normal 45, that explained why it wouldn't run.

Pulled the pump flange out, checked the general condition of pump, filter, screen, wires, all looked good.
Ran the pump directly with 12V, spun like normal.
Ran it with 12v directly to the external plug, spun like normal.
Buttoned it all back up.
Turned the key.....wuhhhhhhhhhhhh.


Culprit:



Which is really odd.
Every other relay failure has been total, none of this 'runs at 1/3 speed' business.

Opened it up, found the contacts looking like this:



Not particularly bad in the grand scheme of relay contacts, but there you go.
Possible there was another problem in the rest of the 'wiring' in the relay, but didn't see anything.

In any case, a new relay got it all back to normal.