Oil, lots of oil, in my airbox (Now I know why)

[clubhousemotorsports]

Nice pictures.

Yes your cases are made in 1998 November. This should make them the same all the way up to 2002. the same as my 2002 m620 cases.

You should have a small pin hole (piston oil jet) in the horizontal hole. As you look inside the horizontal case hole you should see a small pin hole on the left hand side. It is on the opposite side of the vertical jet hole. I do guess it is possible that ducati forgot to put one in or simply decided the horizontal did not need one.  I remember drilling those holes on some race motors we built in that era but  I do not remember which cases or why. Seems odd to have 1 drilled and not the other.

I can remove and replace rods in larger case motors such as the 900 and up (doing a 748 now) but I am not sure I could on a small case motor with the smaller bore. It would be hard to fit torque wrenches in there, I have not tried one yet to see if I could pull it off. If  the cases are out of the bike I would not bother and just split them you have already done most of the work.

The oil feed o-ring at the base gasket will deform and leak if you get gasket sealer on it. The cases/cylinder grow and the o-ring would be happy but the sealer has stuck it to one side and it will deform. We had this happen to us as well and learned to keep the o-ring clear of sealer. We once tried to use sealer on o-rings and that simply does not work. One or the other, but not both.


Your tests show that outside of the missing horizontal piston jet you are getting clear passageways everywhere. It appears there is no blockage and if low pressure air is getting through the oil should as well.. Have you inspected the oil pump? I would also look at both rod bearings if you are pulling the rods to make sure you were not low on pressure. With functioning oil; jets and good pressure (any idea of pressure, was it tested) I see no reason for both pistons to be burnt on the bottom. The vertical should have had a functioning oil jet but the crack would have burnt it pretty good . the horizontal may have had no jet so maybe it was a little of both.

Brings us back to why did it crack?
If the jet was cooling the vertical piston and the crack then happened I would guess the piston just fatigued.

Have you figured out what has happened to the "chipped" rod? Coincidence that it was the one with the cracked piston?  Or related.
Any other damage in the motor? Have you found anything that may have gotten in the piston rod area to maybe crack a piston and damage a rod? I had a SV650 race bike in the shop last year with a blown gearbox and the broken teeth junked the rods and cylinders, I would look things over well. might not be related but I would not take a chance and not look.

It is hard to tell from a picture but you had a picture earlier of the Carrillo rod burnt as well , I would send at least that rod back to Carrillo to have it reconditioned/inspected.  Carrillo rods are really good stuff but the small end of them is the weak point and you have "chips and visible heat damage on yours.

oops!
I just saw the picture of no oil jet for the Horizontal. Yes I would drill a hole for one. You need to remove the main bearing shell and you will see a cavity that runs around the bearing. It should have a feed hole to it from the oil system. Drill with small bit the same size as the verticals jet hole. Angle the hole so that it points at the bottom of the  piston when the crank cheek is clear  Should be TDC for the Horizontal. Aim the drill to end up in the oil channel and that should give you a horizontal oil jet. you can see the flat area where the jet should be in the center left side of the hole.

[stopintime]

.........

It is hard to tell from a picture but you had a picture earlier of the Carrillo rod burnt as well , I would send at least that rod back to Carrillo to have it reconditioned/inspected.  Carrillo rods are really good stuff but the small end of them is the weak point and you have "chips and visible heat damage on yours.
...........

I emailed the rod pictures to Carrillo and they think it looks like melted aluminum. I need to check to confirm, but it seems right - the 'chipped' area has a surface that looks like the normal surface. I don't know this stuff, but the 'chip' might be a chip of the once melted aluminum, not of the rod surface itself. Carrillo suggest media blasting the remaining aluminum, magnaflux for damages and recondition. If I wish, they can do it for $120.
This all requires the cases to be split - which I hope to avoid...

[clubhousemotorsports]

Sounds like someone else should be splitting those cases at no charge to you to make sure everything is alright. If you need new rod bearings and rod bolts plus a re-condition on the rod it will be much cheaper than letting a weakened part run in your soon to be fresh motor.

I can show a picture of what that could look like, and I got off easy...I think.

[Privateer]

My money's on a broken reed valve in the breather.

the breather on my 04 620 has been misting a lot more oil lately than ever before.  i can't seem to get it off to inspect it.  It's the OEM breather.  I was afraid to use too much force and destroy it.  Is there some magic to removing it and opening it up?

[stopintime]

Bike is back and running


Details at this point:
the piston damages are normal - 'nobody' has ever seen 'race'/high comp pistons with 50,000km on them. Now we know how long they can last - or not.

The rocker arms and cams weren't damaged due to heat or lack of oil, but because they were knocking together and finally the rocker chrome gave up. As much as I'd like to blame someone else... I have to swallow this one myself because I treated it too hard (Alps, Autobahn, trackdays, racing) without valve adjustments for ~9,000 km. The first edition of tuned engine didn't require much shorter intervals, but this engine obviously did. There were no real signs of friction burn and I skipped at least one required valve adjustment. Lesson learned.

New pistons are in. The type I had are no longer available, so now I'm running 90mm Pistals called 750F1 Laguna Seca (IIRC). The dome on these reach much higher and would create WAY too much compression, so they were machined. Not enough material to lower them much/at all, but reduced the diameter of the dome. Strange looking, but with correct squish edge and ordinary compression 10.9/1.

Rods are fine. Like Carillo suspected, melted aluminum on the small end. Nice and round small end hole.

Didn't see exactly what was done, but a new O-ring arrangement is in place. Since the interface between my '98 750 cases and cylinders didn't have guides/locating dowels, which may have allowed movement, they installed guides to keep those parts from floating. The theory is that this might have caused or contributed to the dislocated O-ring. We'll see how well it holds up.

I asked about the missing horizontal oil jet and was told where it is. It's an opening, almost like a gap or a crack, somewhere close to the bearing. It squirts oil onto the rod which in turn flings it toward the piston. At least, that's how I understood the explanation.

The horizontal cam is ok - the vertical is ~ok, but will be replaced 'soon'.

I only did a short and mild test ride, but it seems to run smooth and strong with normal sound and vibration.


Updates will follow as we go along 

[suzyj]

Nine paragraphs and not a single picture. Not good enough!

Seriously tho, awesome that your bike is running again.

[Speeddog]

the breather on my 04 620 has been misting a lot more oil lately than ever before.  i can't seem to get it off to inspect it.  It's the OEM breather.  I was afraid to use too much force and destroy it.  Is there some magic to removing it and opening it up?

No magic.

Is it the all-plastic with a hex (actually octagon IIRC) on the lower part?

[Privateer]

No magic.

Is it the all-plastic with a hex (actually octagon IIRC) on the lower part?

yes. 

I didn't want to destroy it getting it off so when it didn't turn easily I stopped.  I've heard elsewhere the plastic ones can crack pretty easily.

so just slide in a corresponding open end wrench and turn CCW?

[Speeddog]

yes. 

I didn't want to destroy it getting it off so when it didn't turn easily I stopped.  I've heard elsewhere the plastic ones can crack pretty easily.

so just slide in a corresponding open end wrench and turn CCW?

Theoretically, yes.

I've not seen an open end wrench that will fit over it *and* fit in that space.

I can't remember what I used the last time I took one off, perhaps smooth jaw channellocks.

[Privateer]

Theoretically, yes.

I've not seen an open end wrench that will fit over it *and* fit in that space.

I can't remember what I used the last time I took one off, perhaps smooth jaw channellocks.

yeah after wrangling it for the better half of an hour I see your point.  Something is definitely going on there and up front somewhere.  oil mist all over the engine.  back area near the breather and down near the temp sensor, on the transverse surfaces of the rear sets... /sigh

[Privateer]

yeah after wrangling it for the better half of an hour I see your point.  Something is definitely going on there and up front somewhere.  oil mist all over the engine.  back area near the breather and down near the temp sensor, on the transverse surfaces of the rear sets... /sigh

  It seems mine is leaking from the middle of it, kind of where there's a seam running the circumference.


does the oem breather come apart?  Is there something going on inside it I can fiddle with or clean up to stop the oil seep?

[Privateer]

well after some makeshift repairs to the OEM breather, a garage scrounge band-aid on it, and a week commuting there doesn't seem to be any oil leaking from it.  Not sure about the mist through the filter.  that's a project for another time.

[stopintime]

New cam going in 

Oil leak is back - will (?) be fixed by blocking the through-cylinder oil passage and installing outside line from oil pressure sensor location to cam cover. Fingers crossed for a final solution.

[koko64]

900ie cams. (I looked up Brad's cam specs)
So going for "more" cam again.

[stopintime]

900ie cams. (I looked up Brad's cam specs)
So going for "more" cam again.

Same as now, but in better condition than my current one (see pictures earlier).