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Valve let go

377 Views 2 Replies 2 Participants Last post by  Foreman96
Hey guys, new member. Bought an 04 450 a week ago. Put some fairly hard miles on. Third day of riding the intake valve let go and destroyed the head, piston and jug. Got the motor out of the bike and pulled the top end and front cover off. Piston has a gaping hole where the valve was lodged in and found some aluminum in the case but nothing too serious. Question is should I be alright to give a good rinse with brake clean and toss a new top end on? Buddy has a new top end off a 400 that I can steal. Don’t really want to keep tearing apart the case as I’m already over my head.
Thanks for any advice
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I can understand not wanting to tear it down the rest of the way, and I’d imagine it would likely be ok…. But I’d hate to put it all back together and have some debris I didn’t get out ruin the crank or the case. If it were me I’d want to take it the rest of the way apart.
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Update: Found a parts motor at a local Atv shop, the guy took the motor as payment 5 years ago and sold it to me for $400. He never seen it ran as it was out of the quad when he was given it although the guy said it worked fine an didn’t smoke. I ripped the top end off that motor and swapped it onto the bottom end of mine as the parts motor wasn’t electric shift. I rinsed my bottom end out very thoroughly with gas and brake clean and got quite a few big chunks of aluminum. As of right now the bike is running probably better than before and shifting wicked. I’ve dumped the oil twice already and will do so once more in the morning before I take it riding all weekend for my buddies stag party. Pretty proud so far about having it back running in 3 days and doing my first ever top end.

Let’s see how these next few hundred miles go!
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