2003 yz 450 seized, hole in front of the engine

7 replies to this topic
  • Curtybird95

Posted April 21, 2013 - 05:30 PM


My bike seized up the other day, like i the kick starter wont even go down and i was looking on it today and noticed a hole the size of a fifty cent piece on the front of the engine, what couldve blown through this?? Expensive?? New parts??

  • jojo1224

Posted April 21, 2013 - 05:47 PM


The connecting rod broke, lots of new expensive parts. :thumbsdn:

  • Curtybird95

Posted April 22, 2013 - 08:29 AM


Avg price? And mine engines not tuined right?

  • grayracer513

Posted April 22, 2013 - 09:19 AM


Depends on what you mean by ruined. You'll be looking at a minimum of $800 in parts if you got really lucky, and closer to $2500 if not, plus the welding and machining (or replacement) of the broken crankcase, plus labor. It can be repaired, but feasibly? That's your call. First thing that has to happen to be more certain than that is to tear it down and evaluate the damage.

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  • MaxPower

Posted April 22, 2013 - 01:05 PM


Use this as a life lesson Son. When a 4 stroke is knocking,fix the problem before it gets worse, they dont heal themselves. I thought you were joking when you posted the video of your engine knocking and said you were going riding on the weekend

  • NitrousR1

Posted April 28, 2013 - 02:07 PM


I would call it ruined, the repair might cost as much as the bikes worth. Count on needing new crankshaft new cylinder new piston possibly case or cases depending on damage. Most likely new cylinder head, unless if you got really lucky and it can be repaired which is rare. 5 new valves new cam chain, possibly cams depending on damage and wear. Maybe buckets and a lot of other parts all depending on how they look and measure out during tear down. Add in labor with the cost of these parts and u will probably be upside down on the bike. And that's if everything else is in perfect shape on the bike. Please take pics of the damage so we can try to evaluate the cases

  • RagingBunny

Posted April 28, 2013 - 10:06 PM


I would call it ruined, the repair might cost as much as the bikes worth.

I agree with NitrousR1. The engine is most likely ruined. Especially if you pay a dealership/shop to do the work it's gonna cost way more than the bike is actually worth. My dads 2008 yz450f has started to knock A LOT lately. I'm immediately taking it apart next weekend to see whats going on in there. But you might even want to sell each part off on ebay. eg. wheels, frame, subframe, swingarm, and what ever else survived in the engine!

  • DGXR

Posted April 29, 2013 - 09:19 AM


Avg price? And mine engines not tuined right?

After reading your first thread about this bike, and now reading this one, good grief please just TAKE APART THE MOTOR -- get someone to help you do it or get someone else to do it for you. It's either going to be junked or totally rebuilt, so there's no harm by tearing into it. Heck, I'd take it apart myself if it weren't 2000 miles away. :)

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