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engine blow up for my rmz?

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i have an 05 rmz250 i just bought last week. the last owner said everything has been rebuilt including the crank, rod, piston, valves, and cams. he said it had about 4 rides on it and it sounded pretty strong. i was riding it yesterday in a tight trail and jumped a root and it all of the sudden started knocking bad . it has a hot cams intake cam and i think it has ti valves. i am thinking the piston hit one of the valves and shattered it:excuseme: , but does anyone else have any suggestions to what happened?:applause:

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The valve would not shatter. If it hit one it would hit both or all 4. Does it still run? Knocking usually indicates a rod bearing going. The fact that you hit a root at that time is probably coincidental, as i don't see any way that could affect the motor.

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well i've heard since ti is such a high tensile strength it only shatters, it doesn't bend. i also heard that if you have an aftermarket cam, it lowers the valves or something and if you slam some whoops really hard or something, the inertia causes the valve to drop and the piston hits it and shatters the valve, that is what some guy told me. but yes, it does run still. i just popped the valve cover off and i can see the valves are opening but the kickstarter won't go down anymore after about 1/3 of a kick, i think there is something that broke that is hitting the piston and valves and won't allow the piston to go to the top of its stroke. i am stumped, thanks for the help though man, any other suggestions anybody?

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Just looking at it from the outside will not repair it and all the advice in the world won't help as none of the forum readers have a magic wand to make it go away.Why not just tear it down and let us know what you find.All the good meaning replies are only speculation.Enough said!

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How does it run if it does'nt kick?Just curious, not trying to be a smartass. Ti valves don't shatter and no whoop or bump in the world would make a valve hit the piston. Ever.

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the kickstarter will kick down, but it takes a lot more force than it normally would. i am going to tear it down, i am just wondering what you guys think it is before i do it.

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Maybe the auto decompression mechanism on your ex cam is stuck open or came apart. that would account for the hard to kick and the tapping. Does it run ok still, any smoking, how loud is the tap? Is it a heavy rap or a ticking sound?

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it wont run if a valve is shattered or broke and it will run bad if a valve is way out of wack

a ticking noise indicates a valve has moved out of place and you either have it checked out or check it out yourself,

a loud knocking noise would be a crankbearing/ or rod bearing, i would check valves before you strip the whole engine though

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i just tore the bike apart and the cylinder, cams, valves, head, piston etc. were all okay and the timing was spot on. so i started to wiggle the timing chain around and i heard the clacking and knocking down by the clutch cover. i took the whole clutch cover off and found bits and pieces of a gear and a bolt. it turns out the idiot that had the bike before overtightened and snapped a bolt or didn't tighten the bolt enough right next to the shifting fork mechanism and it was floating around in there until it got sucked in with the main crank gear and the clutch basket gear. both are shot but i have only found the bolt head and the screw part and one other gear tooth from the crank gear. unfortunately i cannot find the gear tooth off of the clutch basket on the clutch side. therefore, i think it got into the cases so i will probably have to split the cases,:applause: a big job.

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