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Discussion Starter #1
I have owned my zx12r since new.59,000 miles.I changed the oil over 30 times with mobil 1 car 15-50 oil.The engine saw redline a million times but never purposely rode wheelies like those squids. It ran like a mother fucker till the second it blew up..I totally disassembled the engine.Beside the fact that #3 rod explode thru the cylinder and cases front and rear WHY.
There is no bluing from heat anywhere on this engine,The Rod #3 big end still on the crankshaft still spins smooth as butter.I believe the head can be reworked and used again .Do wrist pins work their way out and cause this.Can a rod just crack in half for no reason.The starter clutch is right by # 3 rod.Could it have caused this...............
 

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pull the cap off, i bet the bearings are toast and now thats its cooled down, it has clearance.

you said it had a knock in it right?
 

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Discussion Starter #3
pull the cap off, i bet the bearings are toast and now thats its cooled down, it has clearance.

you said it had a knock in it right?
yes a little at idle. Both nuts are smashed and will have to be cut off......

Hey Scott.On new engine break in oil what do you use.Every new bike I bought has to me a different kinda oil in it. At 500 miles when i change it it looks grey and translucent. It smells different too to me.Weird shit.What do you think.
 

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i use regular kawi oil 10 40, run for a bit, then change filter and oil to what ill be using
 

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Discussion Starter #6
Why 15-50 oil? Kawi specs 10-40. Synthetics are even a little thinner for the same viscosity.
right out of my owners manual. 10/40,10/50,20/40,20/50
 

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... #3 rod explode thru the cylinder and cases front and rear WHY.
Hours on strategic parts.

Do wrist pins work their way out and cause this.
No. Wrist pins tend to walk out of the piston, cause 2 gouges at the cylinder wall due to the pin's contact points at the circle or the pin. The clip usually drops down onto the sump cover. The engine eventually knocks.

Can a rod just crack in half for no reason.The starter clutch is right by # 3 rod.Could it have caused this...............
No. Back to a stressed part, or more like a stretched part. The piston speed is huge. The piston is heavy. So when you spin it up, the piston wants to keep moving. It pulls the rod like taffy. There is your stress at the hours on the bike.

Did you drag race it? Beat it hard. Missed too many shifts at high rpm? Stretch is the killer. Hours of one too many rpms, meaning, when the bike blew, were you beating crap out of it a few minutes before or did you WOT as it blew up?
 

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i doubt the rod just stretched. i think theres 30 000 on the black bike and its yrs here have been pure torture at the drag strip. the past season i was running heavier than normal pistons (i wish they were light, but price you pay for rugged sometimes) and routinely see more than the factory rev limit. to be honest it saw 13400 once(mistake) a couple yrs ago. i dont recommend this as even though it ran fine after, the winter tear down/inspection showed some of the in valves were slightly mushroomed. (wouldnt pull through the guide) i hit the tops with a dremmel, replaced the bad ones and ran it again. rods are stock. i do plan on putting carrillos in before i go over 20 psi boost. (it went 173 on 13.5 ;) ) this motor/fuel/turbo system are making great power imo.
 

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IMO as has been said ,its had a hard life at the drag strip , to have those Miles on it its done well .. How many times has it smacked the limiter ? every time any motor does it free loads the rods , hence loading up the rod more than necessary ... your motor done well under the circumstances (being a high revving/screamer engine) so I would be happy with that if it was mine ..
PS to do the times you have on it she's been ridden well !!
 

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i doubt the rod just stretched.
Taffy True! Everything is x-rayed for stress cracks, air bubbles in the casting, etc., before it goes on to the assembly stations.

... i was running heavier than normal pistons
Guys run stronger rods for extended rpm just because of both rpm and piston weight change.

Look at it this way. Factory ties a pingpong ball around your nut sack, you jump off a step, land on your feet. That means, max weight for dependability. YOU come along, tie a bowling ball around your nut sack, you jump off a step ladder.

How do your balls feel now? Are they still attached to your body?

Signed,

Whathe fuck you think I'm guessing and you come along and quantify the theory? :clap: :crazyloco:
 

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my results prove the strength of the oem rods. its been a 1287, a nitrous fed 1287 and now turbo. nuff said. now go test your own ball theory lol
 

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Factory parts are tested by manufacturers for mean time to failure.
If the number of passes for a test satisfies the factory and manufacturers' quality assurance standards, the components will get used in production. This does not mean that there were no failures on test and it can be expected that not all parts will survive in working machinery.
Aircraft bolts for example are far more expensive than standard bolts, not because they are better, but because a higher percentage are tested. This still does not guarantee any component will not have a working failure, it just theoretically makes it less likely.
Saying that your rods were fine when used beyond spec just proves that you had 4 good rods and no more.
 

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i guess muzzys did too
 

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It was never identified why Dan Millhollands 1290cc motor spit a rod after 500 miles of street riding and even a few roll on races where it was run up to high speeds. Bolted to the dyno, properly warmed up and on the second pull I believe it spit #3 and bandsawed the cases. It was thought the piston seized and caused the failure but the piston didn't back that theory up. It came down to a weak part that most likely had a flaw hidden well enough to escape the naked eye yet large enough to cause a failure with the extra power levels. Sometimes parts just fail. We all know of the ZX11 and the rod failures they had. Terry Kizer made a small fortune fixing oil pans to cure the problems. He stated in print that a ZX11 Rod was good to 300 Hp but I always found it funny he ALWAYS without fail had aftermarket rods in his own motors. We most all pay life insurance money for many years to protect out families from unexpected hardship in case we check out early. Buying premium rods is the same type deal. It's insurance on having a stock rod check out earlier than say Muzzy said it should. Any good mechanic knows that even the best parts fail when they shouldn't and any part pushed way past it's designed limits is far more likely to fail. This thread is proof positive that these rods can and do fail in STOCK motors after years of bullet proof life. Think about it
 
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