OMR: '76 KZ900 Restoration/Modification

Old Man Rock wrote: :laugh: :laugh: :laugh:

And yes we have Winter in Az, just invisible white stuff... Crap is harder then hell to shovel off the drive way, pisses me off...

Glad to hear you're alright man! Pistons, rods and blocks are replaceable. OMR isn't

mtbspeedfreak wrote: Glad to hear you're alright man! Pistons, rods and blocks are replaceable. OMR isn't

Yeah that's the major thing. I'm looking forward to reading up on your new build! Might give me the kick in my ass to get me rolling a little quicker on my projects :S

testarossa wrote: Holy crap! That sucks donkeys. Where the hell is that piston? All over the side of the road? Good thing you didn't eat it when all that oil decided to exit stage right.

Man you sure are tough on engine cases. Hopefully all those bits of piston didn't foul up everything else. :sick:

The piston is gone, and if I'm looking at the pictures correctly even the bottom of the #4 cylinder sleeve is gone and that was made of steel! Where did that go? Did it break off in the engine case? Ed

Thanks all for the concern for I'm fine, not even poopy pants when this occurred.

Seriously, when she went down all I felt was a little hickup as if I hit a flat spot in the carbs with no indication such as a loud bang, pop, knock, tire lock up, tank slapping, high speed wobble, tire lock up, nuts thrown into gas tank etc... NADA!....

BTW... LUV them Michelin Road Pilots serious tires, stick to the road real fine!

Now the Kerker was a singing so most likely just didn't hear the piston going through the case... :blink:

I immediately pulled in the clutch while observing my lanes for vehicle presence, started my move to the right.... listening to decreasing rpm, what she was sounding like... She was done...

I know, I know but this is truly how it occurred, no other way to describe. Freaking weird and I was extremely lucky that day no doubt for this could have been one serious FUBAR of a day. KZ Gods where shinning on Old Man Rock...

Testa, yup looking forward to see what may be left of the piston in the belly of the beast (oil pan)... As mentioned, these images are 100% untouched where this is how I found her... No cleaning or brushing away pieces, remnants of what used to be a piston...

Ok, so here's the deal...

Quit smoking incentive = $300 a month.
Plus play money $200 a month.
~ $500 a month total for bike parts...
Xmass on the way so slight delay... damn it.

January...
1) Have a line on a 1197cc (9:1) kit with Sleeves... includes Rings, buttons, wrist pins, gaskets etc... Get this and the cylinder block out for bore & hone.

2) Get bored/sleeved cylinder block and upper case out for machining (enlarging for new sleeves).

3) Save some more $$$ and get the KZ1000 head out to Larry.

Not going to dick around with the old head, just going to start over with the KZ1000 head.

That's the game plan... Hopefully will be able to stick with it.... I'll post the oil pan images or any other WTF images as we go....

OMR

You think that maybe any of this was due to the serious overload that was placed on her awhile back??? Hmm, hefferitus?
Maybe the wristpin circlip came loose and from there the rest was all but history. I remember oldkawsforever riding with us to milwaukee and his engine took a dump...That's always a sinking feeling.

There's so little left on that one cylinder, it's probably best to investigate the other three to see if you can see signs of detonation, or any piston seize marks on the remaining pistons. How are the ring lands on the three surviving pistons - are any of the rings trapped?

It's strange the piston totally disintegrated and the valves are still in the head. In most bad trashing of motors I've seen, it's a broken valve that did most of the damage.

If that cylinder ran very lean, you'd expect it to be just a hole in the piston. So it seems likely you had a piston failure - possibly from seizing and breaking apart. What punched the hole in the cases? Presumable a chunk of the piston skirt.

When you took the 4-1 pipe off, any debris in the pipe? The picture suggests the valves are in very good shape - so everything had to go downwards?

How were the cam bearings? They would be the first to show an oil feed issue.
When you pull the oil pan off, check the oil pump. Do you know if the oil light came on or not?

Staying tuned...interested in the investigation-diagnosis... sorry to hear bout this man. Real bummer ...but on the flip side you get to go big! :evil:

I wonder if an oil passage was clogged on the RH side of the case/block?

Plum, your up. :lol:

Yes, what Jeff said about the valves still intact! (good point) I blew up a brand new engine after a valve broke.... it was horrific (brand new stage 2 head & everything...)the crank/rear end locked-up really fast and the ass end of my bike jumped out into traffic. I grabbed the clutch and the ass end literally jumped over to the right side of pavement..... (think extremely VIOLENT tankslapper) I was only doing 60 mph and it was just pure luck I didn't crash.

It almost seems like the piston let go at BDC and snapped the sleeve of at the same time. Sure is a strange situation. This could of been real ugly for you OMR, glad your OK.

Doug

Excellent questions Jeff...

As for surviving Pistons/rings/sleeves/timing components etc... All seem normal for an engine with ~ 6K miles on them.

Regarding the camshafts, cam bearings, oil in the head, timing components etc... ALL normal, no pieces of aluminum, aluminum dust, excessive wear, signs of holly crap etc... NADA!

Piston failure - possibly from seizing and breaking apart. What punched the hole in the cases? Presumable a chunk of the piston skirt. This is what I'm thinking where the sleeve came apart, possibly raised and the piston caught it and went to shit from there... Either of the two seems the most likely cause. You would think I'd feel that for sure but nope.....

When you took the 4-1 pipe off, any debris in the pipe?
Nope, unless trapped in there which I'll have to investigate closer but as mentioned to Larry, the head exhaust port shows signs of aluminium dust but no pieces as seen on the intake port.... :blink: I know, I know, how the hell did this get in here (intake).... :blink: :S

Basically all went straight down through the case and oil pan. I'll know more this weekend when I can get into the belly of the beast.... As always, I'll post images.